Chapter 3
Avena
Igor G. Loskutov and Howard W. Rines
Devoted to Ken Frey – Oat Breeder
3.1 Introduction
Oat is one of the most important cereal crops in the
world. The genus Avena L. includes cultivated species
with different ploidy levels and a number of wild
species reflecting a wide range of botanical and ecological diversity. A majority of these forms came from
the centers of origin, which by definition shows great
diversity of Avena species. With this in view, oat
species became the subject of investigations to specify
the complex organization of the Avena genus and
indicate aspects of its evolution and phylogenetic
links between the species. Further search for agronomical traits and utilization of new oat breeding sources
is very important for breeding purposes.
3.1.1 Basic Botany of the Species
3.1.1.1 Taxonomic Position of Avena Species
Investigation of species diversity using morphological
traits is very important for their systematization and
determining taxonomic position. Taxonomic and morphological descriptions of species of the genus Avena
L. was started as far back as the sixteenth century
(Tournefort 1700) and continues till today. A great
number of species had been described by a number
of authors since establishment of the system of binary
I.G. Loskutov (*)
Department of Genetic Resources of Oat, Barley, Rye, N.I.
Vavilov Institute of Plant Industry, 44, Bolshaya Morskaya
Street, St. Petersburg 190000, Russia
e-mail: i.loskutov@vir.nw.ru
nomenclature proposed by C. Linnaeus (Linneaus
1753) (Table 3.1). In most cases, characterization of
a species was initially performed on the basis of morphological traits.
An example of one of the first descriptions of the
diploid species is the characterization of cultivated
Avena strigosa (Schreber 1771). Later, this species
was described as A. hispanica Ard. (Malzev 1930).
Another wild diploid species A. pilosa was first
described during examination of the material collected
in the Transcaucasus (Marshall Bieberstein 1819).
During processing of the Algerian materials, the
same species was described under the name A. eriantha
Durieu. Another original species was described under
the name A. clauda (Durieu de Maisonneuve 1845).
These two species are morphologically similar: the
only distinction is that A. clauda disarticulates single
florets instead of spikelets, like A. pilosa, due to the
presence of a callus only in the lowest floret, governed
by one or two genes (Rajhathy and Thomas 1967).
According to the opinion supported by Malzev (1930),
disarticulation of spikelets is an advanced way of seed
distribution. With the help of two awns in a spikelet,
seeds can move and twist into the soil surface more
efficiently than with only one awn of a single floret.
Moreover, with a spikelet, several seeds, instead of just
one, bury into the soil simultaneously.
There are two more closely related species, one
described under the name of A. ventricosa (Balansa
1854) and the other as A. bruhnsiana (Gruner 1867).
Along with morphological and physiological similarities, and thanks to the elongated callus, their seeds can
screw into the toughest stony soil even under the
strongest drought in the steppe, deserted areas, or
on ranges. Along with the above-mentioned species,
A. longiglumis was initially described by the author in
the course of processing the materials from Algeria
C. Kole (ed.), Wild Crop Relatives: Genomic and Breeding Resources, Cereals,
DOI 10.1007/978-3-642-14228-4_3, # Springer-Verlag Berlin Heidelberg 2010
I.G. Loskutov and H.W. Rines
Table 3.1 The history of description Avena species
Species
Ploidy
A. fatua L.
6
A. sativa L.
6
A. sterilis L.
6
A. strigosa Schreb.
2
A. barbata Pott ex Link
4
A. hirtula Lag.
2
A. pilosa M. Bieb.
2
A. clauda Durieu
2
A. longiglumis Durieu
2
A. occidentalis Durieu
6
A. byzantina C. Koch
6
A. abyssinica Hochst.
4
A. macrostachya Balansa et Durieu
4
A. ventricosa Balansa
2
A. wiestii Steud.
2
A. ludoviciana Durieu
6
A. bruhnsiana Gruner
2
A. vaviloviana (Malz.) Mordv.
4
A. magna Murphy et Terrell
4
A. murphyi Ladizinsky
4
A. prostrata Ladizinsky
2
A. damascena Rajhathy et Baum
2
A. canariensis Baum, Raihathy et Sampson.
2
A. atlantica Baum et Fedak
2
A. agadiriana Baum et Fedak
4
A. insularis Ladizinsky
4
Year of description
1753
1753
1762
1771
1799
1816
1819
1845
1845
1845
1848
1851
1854
1854
1855
1855
1867
1927
1964
1971
1971
1972
1973
1985
1985
1996
(Durieu de Maisonneuve 1845). According to Malzev
(1930), all the mentioned species are primitive ones,
and this view was later supported by other researchers
(Rajhathy and Thomas 1974).
The diploid oat A. prostrata was described during
exploration of the southwestern coast of Spain by a
collecting mission. The most typical characters of the
species are the minimal size and some other traits
related to the grains as well as the prostrate juvenile
growth of the plant (Ladizinsky 1971b). The species
A. damascena, characterized by the semi-prostrate
juvenile growth, was described for the first time during
an expedition to the Syrian territory (Rajhathy and
Baum 1972). The diploid species A. canariensis collected on Fuerteventura Island (Spain, the Canaries)
disarticulates spikelets and has bidentate lemma tips
(Baum et al. 1973), the latter trait not characteristic of
the diploid species. The lodicules and epiblast of the
species are of the hexaploid cultivated type, though it is
not characteristic in all of the diploid species. A. wiestii
was described on the basis of seed samples and
herbarium materials collected in Egypt (Steudel von
Reference
Linneaus (1753)
Linneaus (1753)
Linneaus (1762)
Schreber (1771)
Pott (1799)
Lagasca (1816)
Marshall Bieberstein (1819)
Durieu de Maisonneuve (1845)
Durieu de Maisonneuve (1845)
Durieu de Maisonneuve (1845)
Koch (1848)
Hochstetter (1852)
Balansa and Durieu Maisonneuve (1854)
Balansa (1854)
Steudel von (1855)
Cosson and Durie de Maisonneuve (1855)
Gruner (1867)
Malzev (1930)
Rajhathy et al. (1966)
Ladizinsky (1971a)
Ladizinsky (1971b)
Rajhathy and Baum (1972)
Baum et al. (1973)
Baum and Fedak (1985a)
Baum and Fedak (1985b)
Ladizinsky (1998)
1855). The species A. hirtula was initially described
in Spain (Lagasca 1816) and A. atlantica – during a
collecting mission to the Atlantic coast of Morocco
(Baum and Fedak 1985a). Morphologically, the latter
species is similar to A. hirtula, with the only difference
that A. atlantica disarticulates spikelets instead of
single florets.
The tetraploid species A. barbata was initially
described in Portuguese material (Pott 1799). Later,
this species was described as A. hirsuta Roth (Malzev
1930), though according to Baum (1977), A. hirsuta is
a synonym of A. matritensis Baum. Romero Zarco
(1990) subdivides A. barbata into A. barbata subsp.
barbata proper and A. barbata subsp. lusitanica, while
Baum (1977) assigns the species rank to the latter
subspecies and proposes the diploid species A. lusitanica Baum. The ploidy level of the latter species
has been questioned recently (Markhand and Leggett
1996). The species A. vaviloviana has been found by
Vavilov (1965b) in Ethiopia and initially described
as a subspecies of A. strigosa subsp. vaviloviana
Malz., but later it was promoted to a species level
3 Avena
(Mordvinkina 1936). Malzev (1930) believed this
species to be a wild parent form of A. abyssinica
(Hochstetter 1852) with which it shared the same
natural habitat that differed from that of other tetraploid species. According to Vavilov, the African group
of oats, studied by Trabut (1909), had to be subjected
to a special study, as there was no reason for uniting it
with the European and Asian species (Vavilov 1965a).
At present, this group of species is considered independent from the others (Baum 1977; Loskutov 2008).
The tetraploid species A. agadiriana was first
described from the material collected in Morocco on
the Atlantic and Mediterranean coasts. Morphologically, this species resembles A. barbata (Baum and
Fedak 1985b), but it sharply differs in that A. agadiriana disarticulate spikelets and bidentate lemma tips.
The species A. magna was described during explorations of the Mediterranean coast in Morocco (Rajhathy
et al. 1966). It is believed that this species had been
initially described as A. moroccana Gdgr.; however,
no direct proof of that has been found. The discovery
of A. magna has “filled the last cell” concerning traits
homology in the tetraploid species, as it was the species with only the first lower floret to have a callus.
This type of joint had been previously described only
for the diploid and hexaploid species. Another species, A. murphyi, has been discovered and described
from southern Spain (Ladizinsky 1971a). A series of
morphological traits makes this species similar to
A. magna, and therefore it was attributed to the Pachycarpa Baum section (Baum 1977) characterized by
bidentate lemma tips. The species A. insularis was
discovered and described in Italy, on Sicily. Morphologically, it occupies an intermediate position between
A. murphyi and A. sterilis (Ladizinsky 1998).
The outcrossing tetraploid perennial species A.
macrostachya was discovered and described in
Algeria (Balansa and Durieu de Maisonneuve 1854),
though it is believed that initially it had been described
under the name of Helictotrichon macrostachyum
Holub (Holub 1958). Many researchers, due to morphological characteristics, regarded this species as a
primitive representative of the genus Avena (Malzev
1930; Baum and Rajhathy 1976; Baum 1977; Loskutov
2007).
Although the hexaploid A. fatua was one of the first
described species (Linneaus 1753), a unified hypothesis has not been developed yet on the origin of this
species regardless of the magnitude of research. The
difficulty in identifying the progenitor of this species
relates to its very wide polymorphism, which, according to Vavilov, is linked with its natural broad habitat (Vavilov 1965a). The species A. occidentalis has
been described in the Algerian materials (Durieu de
Maisonneuve 1845). This species greatly resembles
A. fatua but has some differences concerning disease resistance and vegetative period duration. Other
wild (A. sterilis – Linneaus 1762 and A. ludoviciana –
Cosson and Durie de Maisonneuve 1855) and cultivated
(A. sativa – Linneaus 1753 and A. byzantina – Koch
1848) hexaploid species have been described long ago
and a broad spectrum of subsequent research has
been devoted to their taxonomic affinity (Malzev
1930; Rajhathy and Thomas 1974; Baum 1977;
Loskutov 2007).
Thus, the taxonomic position of Avena species
is not always unambiguous. In recent years, numerous collecting missions targeted on oat species have
been carried out with new species being subjected to
thorough investigation.
3.1.1.2 Geographical Locations of Genetic
Diversity and Morphology of Avena
Wild Species
Natural and ecological conditions under which oat
species grow differ considerably in terms of rainfall,
temperature regime, altitude, and soil and subsoil
types. The richest occurrence and highest genetic
diversity of wild oat species in the Old World is
observed in a narrow territory between latitude 20
and 40 N. It stretches mainly through basins of the
Mediterranean, Black, and Caspian seas with very
diverse ecological conditions.
Morphological traits used for oat species characterization relate to the vegetative part of a plant; however, the main taxonomic characters are the detailed
morphological features related to the structure of generative organs.
Diploid Species
Avena clauda Durieu, 1845, Rev. Bot., 1: 360, excl.
syn.; Coss. et Durieu, 1855, Expl. sc. Alger., 2: 111, t.
41, f. 2; Steud., 1855, Syn. Pl. gram., 1: 234; Hausskn.,
1894, Mitteil. Thur. Bot. Ver., 6: 42, 45; idem, 1899,
I.G. Loskutov and H.W. Rines
Mittel. Thur. bot., XIII, XIV: 47, excl. var. solida
Hausskn.; Batt. et Trabut, 1895, Fl. Alger. Monocot.:
180; idem. 1902, Fl. anal. Alger.: 370; Malzev 1930,
Ovs. & Ov.,: 230; Roshevitz 1934, Fl. USSR, II: 260;
Baum 1974, Canad. Jour. Bot., 52: 2243; Tzvelev,
1976, Poaceae USSR,: 242; Rodionova et al. 1994,
Cult. Fl.,: 100–102.
Annual. Juvenile growth prostrate to semi-prostrate. Flowering stem erect, 60–100 cm high. Panicum
unilateral. Spikelets awned, and containing 3–5 florets. Glumes very unequal, lower glume one-half of
upper one with 7 veins. Lemma tips biaristulate to
bisubulate. All florets disarticulate at maturity. Awn
inserted at 1/3 of the lemma. Lemmas small or
medium sized, glabrous, or pubescent; pubescence of
white color. Callus elongated, linear, about 3 mm long.
A. clauda can be found together with A. pilosa. It
grows in Bulgaria, Greece, throughout Asia Minor, in
Turkish, Iranian, and Iraqi Kurdistan, in Uzbekistan,
Azerbaijan, high-altitudinal areas of Jordan, in Israel,
Lebanon, Syria, Algeria, and Morocco. The species
grows under conditions of the steppe climate with up
to 350–500 mm annual rainfall, in mountainous semideserts and deserts, on coastal sands, on gray-brown,
gray-meadow, alluvial meadow, chestnut and podzolic
black soils, as well as on brownish and yellowishbrown stony soils (Malzev 1930; Roshevitz 1934;
Ladizinsky 1971c; Baum et al. 1972a; Baum 1977;
Kanan and Jaradat 1996; Leggett et al. 1992; Sheidai
et al. 2002; Loskutov 2007).
Avena pilosa M.Bieb., 1819, Fl. Taur.-cauc., III
Suppl.: 84; Griseb., 1844, Spicil. Fl. rumel.: 452;
Koch C., 1848, in Linnaea, XXI: 392; Ledeb., 1853,
Fl. Ross., 4: 413; Steud., 1855, Syn. Pl. gram.: 231;
Coss. et Durieu, 1855, Expl. Sc. Alger., II: 109; Batt.
et Trabut, 1895, Fl. Alger. Monocot.: 179; idem. 1902,
Fl. anal. Alger.: 370; Malzev 1930, Ovs. & Ov.,: 233;
Roshevitz 1934, Fl. USSR, II: 261; Rodionova et al.
1994, Cult. Fl.,: 102–105. – A. eriantha Durieu, 1845,
Rev. Bot., 1: 360; Coss. et Durieu, 1855, Expl. sc.
Alger., 2: 109; Nevski 1934, Work. Asie. Univ., ser.
8в, 17: 3; Baum 1974, Canad. Jour. Bot., 52: 2243;
Tzvelev, 1976, Poaceae USSR,: 243; Romero Zarco
1996, Lagascal., 18, 2: 171–198. – A. clauda var.
solida Hausskn., 1885, Mitt. geogr. Ges., 3: 237–239.
Annual. Juvenile growth prostrate to semi-prostrate.
Flowering stems erect, 55–85 cm high. Panicle unilateral. Spikelets awned medium sized and containing
2–3 florets. Glumes very unequal, lower glume one-
half of upper one with 7 veins. Glumes medium
sized, glabrous, or pubescent; pubescence of white
color. Lemma tips biaristulate to bisubulate. Only the
lower floret disarticulates at maturity. Awn inserted at
1/2 of the lemma. Callus linear elongated, about
3–4 mm long.
A. pilosa (syn. A. eriantha Durieu) is usually found
in a mixture with A. clauda. It occurs in Spain, Greece,
Bulgaria, Ukraine (Crimea), Russia (Dagestan),
Iranian, Turkish and Iraqi Kurdistan, Uzbekistan,
Azerbaijan, Turkmenistan, Morocco, Algeria, Lebanon,
Syria, Jordan, and Israel. It grows on poor soils, e.g.,
gray-brown, gray-meadow, alluvial meadow, chestnut
and podzolic black soils, as well as on limestone
slopes, stony gray soils and on pebbly heavy loamy
soils (Baum 1977; Baum et al. 1972a; Kanan and
Jaradat 1996; Ladizinsky 1971c; Leggett et al. 1992;
Malzev 1930; Musaev et al. 1976; Romero Zarco
1996; Roshevitz 1934; Sheidai et al. 2002).
Avena ventricosa Balansa. ex Coss., 1854, Bull.
Soc. Bot. Franc., 1: 14; Coss. et Durieu, 1855, Expl.
sc. Alger., 2: 109; Malzev 1930, Ovs. & Ov.,: 240,
excl. subsp. bruhnsiana (Grun.) Malz.; Ladiz. et
Zohary, 1971, Euphyt.,: 385–387; Baum 1974, Canad.
Jour. Bot., 52: 2243; Tzvelev, 1976, Poaceae USSR,:
243; Rodionova et al. 1994, Cult. Fl.,: 110.
Annual. Juvenile growth prostrate. Flowering
stems erect, about 65 cm high. Panicle unilateral.
Spikelets awned medium sized, and containing 2 florets. Glumes nearly unequal, about 27–30 mm long
with 7 veins. Lemmas small sized, glabrous. Lemma
tips bisubulate. Only the lower floret disarticulates at
maturity. Awn inserted at 1/2 of the lemma. Callus
very long awl-shaped, about 5 mm.
A. ventricosa occurs on Cyprus as an adventive
species. The primary focus of its distribution is located
in Algeria and the secondary one, according to the
unconfirmed reports, in Iran. Its typical habitats are
stony soils with a surface of hard loamy crust, as well
as a range of soils from limy to sandy desert ones
(Malzev 1930; Bor 1968; Musaev and Isaev 1971;
Baum et al. 1972a).
Avena bruhnsiana Gruner 1867, Bull. Soc. Nat.
Moscou, 40, 4: 458, t. IXB; Roshevitz 1934, Fl.
USSR, II: 261; Musaev et Isaev, 1971, Work. AN
AzSSR, 27: 64–65; Rodinova et al., 1994, Cult. Fl.,:
111. – A. ventricosa subsp. bruhnsiana (Grun.) Malz.,
1930, Ovs & Ov.: 242.
3 Avena
Annual. Juvenile growth prostrate. Flowering stems
erect, 70–110 cm high. Panicle unilateral. Spikelets
awned medium sized and containing 2 florets. Glumes
nearly unequal, about 40 mm long with 7 veins.
Lemmas medium sized, pubescent; pubescence of
white color. Lemma tips bisubulate. Only the lower
floret disarticulates at maturity. Awn inserted at 1/2
of the lemma. Callus awl-shaped very long, about
10 mm.
A. bruhnsiana is an endemic species that used to
grow in abundance throughout the Apsheron Peninsula in Azerbaijan in dry sandy and loamy places. At
present, this species can evidently be found only in its
northeastern part near the coastal sands on gray-brown
soils (Malzev 1930; Roshevitz 1934; Musaev 1969;
Musaev and Isaev 1971; Loskutov 2007).
Avena longiglumis Durieu., 1845, Rev, Bot., 1:
359; Coss. et Durieu, 1855, Expl. Sc. Alger., 2: 110;
Steud., 1855, Syn. Pl. gram.: 233; Batt. et Trabut,
1895, Fl. Alger. Monocot.: 179; idem. 1902, Fl. anal.
Alger.: 370; Malzev 1930, Ovs & Ov.,: 238; Ladiz. et
Zohary, 1971, Euphyt.,: 385–387; Baum 1974, Canad.
Jour. Bot., 52: 2243; Rodionova et al. 1994, Cult.
Fl.,: 113–115 Romero Zarco 1996, Lagascal., 18, 2:
171–198. – A. barbata var. longiglumis Hausskn.,
1899, Mittel. Thur. bot., XIII, XIV: 48.
Annual. Juvenile growth semi-erect to prostrate with
nodes covered by hairs. Flowering stems erect,
50–180 cm high. Panicle unilateral to equilateral. Spikelets large and containing 2–3 florets. Glumes nearly
unequal, much longer than lemmas, 40 mm long with
9–10 veins. Lemmas large, pubescent, nearly equal. All
florets awned. Lemma tips biaristulate 12 mm long. All
florets disarticulate at maturity. Awn inserted at 1/2 of
the lemma. Callus very long awl-shaped, about 10 mm.
A. longiglumis can be found in the western Mediterranean, southern Spain, Portugal, Greece, Italy,
Syria, Libya, Morocco, Algeria, Israel, and Jordan.
This species grows on more dense substrates, on neutral red sandy soils, and prefers light sandy soils with a
varying moisture content – from fertile coastal to poor
sandy desert soils (Malzev 1930; Ladizinsky 1971c;
Baum et al. 1972a; Rajhathy and Thomas 1974;
Leggett et al. 1992; Kanan and Jaradat 1996; Romero
Zarco 1996; Perez de la Vega et al. 1998).
Avena damascena Rajhathy and Baum 1972,
Canad. Jour. Genet., 14: 645–654; 1989, Rep. Work.
Gr. Avena,: 19–32; Rodionova et al. 1994, Cult.
Fl.,: 115.
Annual. Juvenile growth prostrate. Flowering stem
geniculate, 70–80 cm high. Panicle equilateral. Spikelets awned small and containing 3 florets. Glumes
equal, about 20 mm long with 7 veins. Lemma tips
biaristulate. All florets disarticulate at maturity. Awn
inserted at lower 1/3 of the lemma. Callus roundedelliptical.
A. damascena was first discovered in Syria and then
in Morocco. The species grows under dry stony desert
conditions on alluvial-pebbly grounds as well as on
red-brown dry loamy sands within the 700–1,650 m
altitudinal range (Rajhathy and Baum 1972; Baum
1977; Leggett et al. 1992).
Avena prostrata Ladizinsky, 1971, Israel Jour.
Bot., 20: 297–301; Baum 1974, Canad. Jour. Bot.,
52: 2243; 1989.
Annual. Juvenile growth prostrate. Flowering stem
geniculate, 50–60 cm high. Panicle unilateral. Spikelets awned small and containing 2–3 florets. Glumes
equal, 12–15 mm long with 9–10 veins. Lemmas
small, pubescent. Lemma tips biaristulate. All florets
disarticulate at maturity. Awn inserted at lower 1/3 of
the lemma. Callus rounded.
A. prostrata was discovered on the southwestern
coast of Spain on poor loess deposits on limy and
metamorphic rocks as well as in stony habitats. Also,
the species has been found in the coastal part of
Morocco on fertile red-brown soils (Ladizinsky
1971b; Leggett et al. 1992).
Avena canariensis Baum, Raihathy et Sampson,
1973, Canad. Jour. Bot., 51, 4: 759–762; Ladiz.,
1989, Rep. Work. Gr. Avena,: 19–32; Rodionova
et al. 1994, Cult. Fl.,: 116.
Annual. Juvenile growth prostrate. Flowering
stems erect, 50–75 cm high. Panicum unilateral. Spikelets awned small and containing 2–3 florets. Glumes
equal, 18–20 mm long with 9–10 veins. Lemmas
small, pubescent. Lemma tips bidentate. Only the
lower floret disarticulates at maturity. Awn inserted
at 1/2 of the lemma. Callus elliptic.
A. canariensis is an endemic species from the
Canary Islands (Spain), where it occurs on Fuerteventura and Lanzarote islands. It grows within the
200–500 m range on piles of basalt stones, volcanic
ash, or well-structured dry volcanic soils (Baum et al.
1973; Baum 1977).
Avena wiestii Steud., 1855, Syn. Pl. gram.: 231;
Roshevitz 1934, Fl. USSR, II: 265; Mordvinkina 1936,
Cult. Fl. USSR,: 423; Baum 1974, Canad. Jour. Bot.,
I.G. Loskutov and H.W. Rines
52: 2243; Rodionova et al. 1994, Cult. Fl.,: 105–108. –
A. barbata var. caspica Hausskn., 1894, Mitteil. Thur.
Bot. Ver., 6: 41, 45. – A. strigosa subsp. wiestii
(Steud.) Thell., 1911, Veirt. Natur. Ges., LVI: 333;
idem, 1928, Rec. trav. bot. neer., XXVa: 435; Malzev
1930, Ovs. & Ov.,: 276; Ladiz. et Zohary, 1971,
Euphyt.,: 385–387. – A. barbata subsp. wiestii
(Steud.) Mansf., 1959, Kulturpflanze Beih., 2: 479;
Tzvelev, 1976, Poaceae USSR,: 242; Romero Zarco
1996, Lagascal., 18, 2: 171–198.
Annual. Juvenile growth semi-erect to prostrate.
Flowering stems erect, 75–140 cm high. Panicle
equilateral. Spikelets awned small and containing
2 florets. Glumes nearly equal, 10–20 mm long with
7–9 veins. Lemma tips biaristulate 3–6 mm long with
2 denticula. All florets disarticulate at maturity. Awn
inserted at lower 1/3 of the lemma. Callus oval, about
2 mm long.
A. wiestii can most often be found in Spain, eastern
Transcaucasia, Azerbaijan, Turkey, Iraq, Iran, Syria,
Jordan, Israel, Algeria, Egypt, in northern Sahara, and
in the Arabian Peninsula. The species grows in the arid
zone with 50–250 mm annual rainfall on sandy loess
soils, limy slopes, gray-brown, gray-meadow and
alluvial meadow soils, as well as on loamy sands in
deserts and volcanic soils (Malzev 1930; Roshevitz
1934; Baum et al. 1972a; Romero Zarco 1984, 1996;
Loskutov 2007).
Avena hirtula Lag., 1816, Gen. Sp. Nov.: 4; Steud.,
1855, Syn. Pl. gram.: 230; Hausskn., 1894, Mitteil.
Thur. Bot. Ver., 6: 42; Mordvinkina 1936, Cult. Fl.
USSR,: 432; Baum 1974, Canad. Jour. Bot., 52: 2243;
Rodionova et al. 1994, Cult. Fl.,: 108–110. – A. lagascae Sennen, 1926, Pl. Esp.: 5980. – A. strigosa subsp.
hirtula (Lagas.) Malz., 1930, Ovs. & Ov.: 247; Ladiz.
et Zohary, 1971, Euphyt.,: 385–387. – A. barbata
subsp. hirtula (Lagas.) Tab. Mor., 1939, Bot. Soc.
Brot., ser. 2, 13: 622; Mansfeld., 1959, Kulturpflanze
Beih., 2: 479; Romero Zarco 1996, Lagascal., 18, 2:
171–198.
Annual. Juvenile growth semi-erect to prostrate.
Flowering stems erect, 70–150 cm high. Panicle equilateral. Spikelets awned small and containing 2–3
florets. Glumes nearly unequal, 10–20 mm long with
7–9 veins. Lemmas equal, small or medium sized,
strongly pubescent. Lemma tips biaristulate with 1
denticulum. All florets disarticulate at maturity. Awn
inserted at lower 1/3 of the lemma. Callus narrow
elliptic, about 2 mm long.
A. hirtula with the highest degree of genetic polymorphism is observed in Spain, Portugal, France,
Italy, and Greece. Besides, in the eastern Mediterranean, the species occurs in Algeria, Morocco, Tunisia,
Israel, Turkey, Syria, and Jordan. Among its typical
habitats are the areas with small-stony or limy soils
and sand dunes (Vavilov 1965c; Rajhathy et al. 1966;
Baum et al. 1972a; Baum 1977; Perez de la Vega et al.
1998).
Avena atlantica Baum et Fedak, 1985, Canad. Jour.
Bot., 63: 1057–1060; Ladiz., 1989, Rep. Work. Gr.
Avena,: 19–32; Rodionova et al. 1994, Cult. Fl.,:
117–120.
Annual. Juvenile growth prostrate. Flowering stems
geniculate, about 95 cm high. Panicle equilateral.
Spikelets awned small and containing 2–3 florets.
Glumes nearly unequal with 9–10 veins. Lemma tips
biaristulate. Only the lower floret disarticulates at
maturity. Awn inserted at lower 1/3 of the lemma.
Callus round-elliptical.
A. atlantica is a Moroccan endemic. Its population
grows on the Atlantic and Mediterranean coasts. The
species climbs up the northwestern slopes of the Atlas
Mountains up to 1,000 m. The most favored by the
species are very dry red-brown sandy and stony soils
in the foothills (Baum and Fedak 1985a; Leggett et al.
1992).
Tetraploid Species
Avena barbata Pott ex Link autopsia spec. orig., 1796,
Herb. Acad. Sc. Petrop.; idem in Link in Schrader,
1799, Jour. Bot., 2: 315; Ledeb., 1853, Fl. Ross.,
4: 412; Coss. et Durieu, 1855, Expl. sc. Alger., 2:
112; Hausskn., 1894, Mitteil. Thur. Bot. Ver., 6: 40,
45, excl. var. caspica et var. longiglumis Hausskn.;
Roshevitz 1934, Fl. USSR, II: 262; Mordvinkina 1936,
Cult. Fl. USSR,: 422; Mansfeld., 1959, Kulturpflanze
Beih., 2: 479; Baum 1974, Canad. Jour. Bot., 52: 2243;
Tzvelev, 1976, Poaceae USSR,: 242; Rodionova et al.
1994, Cult. Fl.,: 91–97; Romero Zarco 1996, Lagascal.,
18, 2: 171–198. – A. hirsuta Moench, 1802, Meth.
Suppl.: 64; Roth, 1806, Catal. Bot., 3: 19; Marschall
et Bieberstein, 1819, Fl. Taur.-cauc. suppl. III: 82;
Baum 1974, Canad. Jour. Bot., 52: 2243. – A. hispida
Hort. ex Steud., 1840, Nomencl. Bot., 2, 1: 172. –
A. japonica Steud., 1855, Syn. Pl. gram.,: 231. –
A. strigosa subsp. barbata (Pott) Thell., 1911, Veirt.
3 Avena
Natur. Ges., LVI: 330; idem. 1928, Rec. trav. bot.
neer., XXVa: 434, excl. var. solida Hausskn.; Malz.,
1930, Ovs. & Ov.; 268. – A. lusitanica Tab. Mor.,
1939, Bot. Soc. Brot., ser. 2, 13: 624; Baum 1977,
Monogr. Gen. Avena: 129. – A. matritensis Baum
1977, Monogr. Gen. Avena: 129. – A. barbata subsp.
castellana Romer. Zarc., 1990, Lagascl., 16: 252.
Annual. Juvenile growth prostrate to erect. Flowering stems erect, 65–210 cm high. Panicle equilateral.
Spikelets awned medium sized and containing 2–4
florets. Glumes nearly unequal with 9–10 veins.
Lemma tips biaristulate. All florets disarticulate at
maturity. Awn inserted at 1/2 of the lemma. Callus
round.
A. barbata with the highest degree of genetic polymorphism is observed throughout the Mediterranean
region and along the European Atlantic coast. In the
East, it is spread through Asia Minor up to the Himalayas and also occurs on the Ethiopian Plateau at
altitudes around 2,200–2,800 m. It grows on limy
soils, on hilly terrain with loess-like soils, in depressions with alluvial deposits on red sandy, volcanic,
and heavy basalt soils, which form on metamorphic
rocks. It is also spread in Brazil, Japan, and Australia
as an adventive species (Malzev 1930; Roshevitz
1934, 1937; Vavilov and Bukinich 1959; Ladizinsky
1971c, 1975; Baum et al. 1972a; Kliphuis and
Wieffering 1972; Whalley and Burfitt 1972; Loon
van 1974; Dillenburg 1984; ; Romero Zarco 1990;
Sheidai et al. 2002; Loskutov 2007).
Avena vaviloviana (Malz.) Mordv., 1936, Cult. fl.
USSR,: 422; Mansfeld., 1959, Kulturpflanze Beih.,
2: 479; Baum 1974, Canad. Jour. Bot., 52: 2243;
Rodionova et al. 1994, Cult. Fl.,: 90–91. – A. strigosa
subsp. vaviloviana Malz., 1930, Ovs. & Ov., 278. –
A. barbata subsp. vaviloviana (Malz.) Nevski 1934,
Work Asie. univ., ser. 8в, 17: 4; Ladiz. et Zohary,
1971, Euphyt.,: 385–387.
Annual. Juvenile growth prostrate to erect. Flowering stems erect, 80–110 cm high. Panicle unilateral.
Spikelets awned medium sized, and containing 2–3
florets. Glumes equal, longer than florets, 20–25 mm
long with 8 veins. Lemma tips biaristulate 1 mm long
with 2 denticula. All florets disarticulate at maturity.
Awn inserted at 1/2 of the lemma. Callus short, oval,
about 3–5 mm long.
A. vaviloviana is an endemic species in Ethiopia,
Eritrea, and Yemen. In these countries, it occurs
everywhere and is very common on the Ethiopian
Plateau at altitudes between 2,200 and 2,800 m, mostly
on cultivated fertile lands (Mordvinkina 1936; Vavilov
1965b; Ladizinsky 1975).
Avena agadiriana Baum et Fedak, 1985, Canad.
Jour. Bot., 63: 1379–1385; Ladiz., 1989, Rep. Work.
Gr. Avena,: 19–32; Rodionova et al. 1994, Cult.
Fl.,: 120.
Annual. Juvenile growth prostrate. Flowering
stems geniculate, about 60 cm high. Panicle unilateral.
Spikelets small, and containing 2 florets. Glumes
nearly unequal, 15–18 mm long with 8 veins.
Lemma tips bidentate. Only the lower floret disarticulates at maturity. Awn inserted at lower 1/3 of the
lemma. Callus rounded-elliptical.
A. agadiriana is a Moroccan endemic species. A
number of its populations have been collected from the
Atlantic and Mediterranean coasts. The species prefers
red-brown sandy and stony soils (Baum and Fedak
1985b; Leggett et al. 1992).
Avena magna Murphy et Terrell, 1968, Science,
159: 103; Ladiz. et Zohary, 1971, Euphyt.,: 385–387;
Baum 1974, Canad. Jour. Bot., 52: 2243; Rodionova
et al. 1994, Cult. Fl.,: 98–100. – A. moroccana Gdgr.,
1908, Bull. Soc. Bot. France, 55: 658; Baum 1977,
Monogr. Gen. Avena: 129.
Annual. Juvenile growth prostrate. Flowering stems
geniculate, 65–100 cm high. Panicle unilateral.
Spikelets large and containing 3–4 florets. Glumes
wide, long, membranous, nearly unequal with 8–10
veins. Lemma tips bidentate. Only the lower floret
disarticulates at maturity. Awn inserted at 1/2 of the
highly pubescent lemma. Callus strongly pubescent,
rounded.
A. magna (syn. A. moroccana Gdgr.), an endemic
species, have been collected on the Moroccan coast
and in the mountains within the altitudinal range
from 500 up to 1,000–1,300 m. Wherever it occurs,
this species grows on fertile, loose, reddish-brown
alluvial loamy soils (Rajhathy et al. 1966; Leggett
et al. 1992).
Avena murphyi Ladizinsky, 1971, Israel Jour. Bot.,
20: 24–27; Baum 1974, Canad. Jour. Bot., 52: 2243;
Rodionova et al. 1994, Cult. Fl.,: 97–98; Romero
Zarco 1996, Lagascal., 18, 2: 171–198.
Annual. Juvenile prostrate. Flowering stems geniculate, 70–80 cm high. Panicle equilateral. Spikelets
large and containing 2–6 florets. Glumes equal with
8 veins. Lemmas wide, equal, mostly glabrous. Lemma
tips bidentate. Only the lower floret disarticulates at
I.G. Loskutov and H.W. Rines
AU1
maturity. Awn inserted at lower 1/4 of the pubescent
lemma. Callus oval.
A. murphyi originates from limited natural areas in
southern Spain and northern Morocco, where it grows
in a typically Mediterranean climate on thick alluvial
soils (Ladizinsky 1971a; Leggett et al. 1992; Perez de
la Vega et al. 1998).
Avena insularis Ladizinsky 1998, Gen. Res. Crop
Evol., 45: 263–269; Hanelt, 2001, Mansf. Encycl. Agr.
Hort. Crops, 5: 2507.
Annual. Juvenile growth prostrate. Flowering stems
geniculate, about 60 cm high. Panicle unilateral.
Spikelets V-shaped, large, and containing 3–5 florets.
Glumes long, equal, with 9–10 veins. Lemmas
medium sized, strongly pubescent. Lemma tips bisubulate or shortly biaristate. Only the lower floret disarticulates at maturity. Awn inserted at lower 1/3 to
1/2 of the pubescent lemma. Callus elliptical.
A. insularis has been found in Southern Sicily and
then in Tunisia at altitudes from 50 to 150 m on
alluvial clay soils with sand-clay and conglomeratestony subsoils varying in color from whitish to gray,
black, brown, or red, with a pH of 7.8, with rainfall
around 400 mm. Later on, the populations of this
species were collected on the same type of soil in
Tunisia (Ladizinsky 1998, Ladizinsky and Jellen
2003).
Avena macrostachya Balansa et Durieu, 1854,
Bull. Soc. Bot. France 1: 318; Baum 1974, Canad.
Jour. Bot, 52: 2243; Ladiz., 1989, Rep. Work. Gr.
Avena,: 19–32. – Helictotrichon macrostachyum
Holub 1958, Pflanzentaxonom,: 101–133.
Perennial, outcrossing autotetraploid plant. Juvenile growth semi-prostrate. Flowering stems erect,
about 100 cm high. Panicle equilateral. Floret anthers
large, yellow, with anthocyan. Spikelets small with the
awns, and containing 6–8 florets. Glumes short, very
unequal, lower glume one-half of upper one with 7
veins. Lemmas medium long, slightly pubescent.
Lemma tips bisubulate. Awns inserted in lower 1/3
of the lemma. All florets disarticulate at maturity.
Callus linear-elongated.
A. macrostachya is a narrow endemic species
found at the very edge of snows (1,500 m) in the
mountainous regions of Djurdjura and Aures (the
Atlas Mountains) in Northeastern Algeria. It grows
predominantly on limy soils (Baum 1977; Baum and
Rajhathy 1976; Baum et al. 1975; Guarino et al.
1991).
Hexaploid Species
Avena sterilis L., 1762, Sp. Pl., ed. 2:118; Ledeb., 1853,
Fl. Ross., 4:412 incl. A. fatua b-trichophylla (C. Koch.)
Griseb.; Coss. et Durieu, 1855, Expl. sc. Alger., 2: 109,
excl. A. sterilis var. minor; Grillet et Magne, 1875, Fl.
Franc. Ed. 3:532, excl. subsp. ludoviciana Durieu et
Magne, subsp. barbata Gillet et Magne; Hausskn.,
1894, Mitteil. Thur. Bot. Ver., 6:38, 44, excl. A. sterilis
f. abbreviata Hausskn.; Thell., 1911, Veirt. Natur. Ges.,
LVI: 312–319, excl. A. sterilis subsp. ludoviciana
(Durieu) Gillet et Magne; idem, 1928, Rec. trav. bot.
neerlan., 25a: 429–433; Malz., 1930, Ovs. & Ov.: 359,
quoad subsp. macrocarpa (Monch) Brig.; Roshevitz
1934, Fl. USSR, II: 269; Mordvinkina 1936, Cult. Fl.
USSR,: 417; Baum 1974, Canad. Jour. Bot., 52: 2243;
Tzvelev, 1976, Poaceae USSR,: 238, excl. subsp.
ludoviciana (Durieu) Gillet et Magne; Rodionova
et al. 1994, Cult. Fl.,: 86–90; Romero Zarco 1996,
Lagascal., 18, 2: 171–198. – A. macrocarpa Moench,
1794, Meth. Pl.: 196. – A. atherantha Presl, 1820,
Cyper. Gram. Sicul.,: 30; Baum 1977, Monogr. Gen.
Avena: 129. – A. maxima Presl., 1826, Fi. Sic.,: 44;
Baum 1974, Canad. Jour. Bot., 52: 2243. – A. sterilis
subsp. macrocarpa Briq., 1910, Prodr. fl. Cors., 1: 105;
Thell., 1911, Veirt. Natur. Ges., LVI: 312–319. –
A. sativa subsp. sterilis (L.) Ladiz. et Zohary, 1971,
Euphyt., 20: 385–387.
Annual. Juvenile growth erect to prostrate.
Flowering stems erect, 30–145 cm high. Panicle equilateral. Spikelets V-shaped, large, and containing 3–5
florets. Glumes large equal. Lemma tips bidentate.
Only the lower floret disarticulates at maturity. Awn
inserted at lower 1/2 of the slightly moderate pubescent lemma. Callus rounded.
A. sterilis is widely spread throughout the
Mediterranean, from the Atlantic Ocean to the Himalayas, namely in Spain, Portugal, Italy, Switzerland,
southern France, northern Iran, Turkey, Ukraine,
Transcaucasia, in all countries of northern Africa,
and in Ethiopia. The highest degree of genetic polymorphism may be observed in the areas with rainfall
from 50 to 800 mm, on almost all types of sandy and
clay soils, on basalt rocks, and at altitudes above
600–700 m. Numerous form of A. sterilis can be
found at present in Japan and South Korea (Roshevitz
1934; Holden 1966; Ladizinsky 1975; Yamaguchi
1976; Garcia-Baudin et al. 1978, 1981; Schuler 1978;
Maillet 1980; Brezhnev and Korovina 1981; Costa
3 Avena
AU2
1988; Romero Zarco 1994; Kanan and Jaradat 1996;
Loskutov 2007).
Avena ludoviciana Durieu, 1855, Act. Soc. Linn.
Bordeaux, 20: 41; Roshevitz 1934, Fl. USSR, II: 269;
Mordvinkina 1936, Cult. Fl. USSR,: 418; Rodionova
et al. 1994, Cult. Fl.,: 78–82. – A. persica Steud., 1855,
Syn. plan. gram., I: 230. – A. sterilis var. minor Coss.
et Durieu, 1855, Expl. sc. Alger., 2: 109. – A. sterilis
subsp. ludoviciana (Durieu) Gillet et Magne, 1875, Fl.
Fr., Ed. 3: 532; Thell., 1911, Veirt. Natur. Ges., LVI:
313; Malz., 1930, Ovs. & Ov., 363; Tzvelev, 1976,
Poaceae USSR,: 239; Romero Zarco 1996, Lagascal.,
18, 2: 171–198. – A. sterilis f. abbreviata Hausskn.,
1894, Mitteil. Thur. Bot. Ver., 6: 39, 44. – A. trichophylla C. Koch 1848, Linnaea, XXI: 393; Roshevitz
1934, Fl. USSR, II: 269; Baum 1974, Canad. Jour.
Bot., 52: 2243. – A. sterilis subsp. trichophylla (C.
Koch) Malz., 1930, Ovs. & Ov.,: 363; Tzvelev, 1976,
Poaceae USSR,: 238.
Annual. Juvenile growth erect to prostrate. Flowering stems erect, 40–150 cm high. Panicle equilateral.
Spikelets large and containing two or rarely 3 florets.
Glumes equal, 25–30 mm long. Lemma tips bidentate.
Only the lower floret disarticulates at maturity. Awn
inserted at lower 1/3 of the pubescent lemma. Callus
rounded.
A. ludoviciana is found throughout Europe, in
eastern Mediterranean, Ukraine, southern Russia,
Azerbaijan, Central Asia, Iran, Asia Minor, southwestern Asia, Afghanistan, as well as along the entire
coast of northern Africa and Mediterranean Sea. It
grows on almost all types of sandy and clay soils and
demonstrates wide genetic diversity. The species has
been brought over to northern and southern Australia
and to New Zealand (Roshevitz 1934; Romero Zarco
1994, 1951; Vavilov and Bukinich 1959; Holden
1969; Guillemenet 1971; Kropac and Lhotska 1971;
Whalley and Burfitt 1972; Garcia-Baudin et al. 1978;
Schuler 1978; Costa 1988; Loskutov 2007).
Avena fatua L. 1753, Sp. Pl.,: 80; idem, 1762, Ed.
2: 113; Lebed., 1853, Fl. Ross., 4: 412, excl. A. fatua.,
b-trichophylla (C. Koch) Griseb. et syn. A. byzantina
C. Koch; Coss. et Durieu, 1855, Expl. sc. Alger., 2:
109; Hausskn., 1885, Mitt. geogr. Ges., 3: 237–239;
idem, 1894, Mitteil. Thur. Bot. Ver., 6: 37, 45,
exl. subsp. sativa Hausskn.; Thell., 1911, Veirt.
Natur. Ges., LVI: 319; Malz., 1930, Ovs. & Ov.,:
287; Roshevitz 1934, Fl. USSR, II: 267; Mordvinkina
1936, Cult. Fl. USSR,: 402–403; Baum 1974, Canad.
Jour. Bot., 52: 2243; Tzvelev, 1976, Poaceae USSR,:
239; Rodionova et al. 1994, Cult. Fl.,: 72–78; Romero
Zarco 1996, Lagascal., 18, 2: 171–198. – A. hybrida
Peterm., 1841, Fl. Bienitz: 13; Koch, 1844, Syn. Fl.
Germ. Helv. Ed. 2.II: 917; Steudel, 1855, Syn. Pl.
gram.: 230; Baum 1977, Monogr. Gen. Avena: 129.
– A. sativa subsp. fatua (L.) Thell., 1911, Veirt. Natur.
Ges., LVI: 319; Ladiz. et Zohary, 1971, Euphyt.,:
385–387. – A. septentrionalis (Malz.) Roshevitz,
1934, Fl. USSR, II: 265; Baum 1974, Canad. Jour.
Bot., 52: 2243. – A. meridionalis (Malz) Roshevitz,
1934, Fl. USSR, II: 266. – A. cultiformis (Malz.)
Roshevitz, 1934, Fl. USSR, II: 268.
Annual. Juvenile growth erect to prostrate. Flowering stems erect, 40–150 cm high. Panicle equilateral.
Spikelets large and containing 2–3 florets. Glumes
equal, 20–25 mm long. Lemma can be hairy or glabrous. Lemma tips bidentate. All florets disarticulate
at maturity. Awn inserted at 1/2 of the lemma. Callus
rounded.
A. fatua grows on different soils under different
climatic conditions ranging from the Tropics right up
to the Polar Circle; it climbs high into the mountains
up to the upper limit of crop cultivation (till 3,000 m)
and demonstrates the highest degree of genetic polymorphism. Wild oat has penetrated almost all agricultural areas around the globe – from the Atlantic Ocean
across Eurasia into Mongolia, Japan, and South Korea;
spread throughout southern and northern Africa and
got into North and South Americas, Australia, and
New Zealand (Malzev 1930; Roshevitz 1934, 1937;
Vavilov and Bukinich 1959; Guillemenet 1971; Baum
et al. 1972a; Kuhn 1972; Whalley and Burfitt 1972;
Nilsson et al. 1973; Yamaguchi 1976; Rines et al.
1980; Costa 1988).
Avena occidentalis Durieu, 1865, Jard. Pl. Bordeaux, 2: 24; Hubbard, 1937, Fl. Trop. Afr., 10: 122;
Baum 1971, Canad. Jour. Bot., 49: 1055–1057; Rodionova et al. 1994, Cult. Fl.: 82.
Annual. Juvenile growth semi-erect to prostrate.
Flowering stems geniculate, 45–100 cm high. Panicle
equilateral. Spikelets large and containing 3–4 florets.
Glumes equal, 16–20 mm long. Lemma can be hairy
or glabrous. Lemma tips bisubulate or shortly biaristate. All florets disarticulate at maturity. Awn inserted
at 1/2 of the lemma. Callus rounded.
A. occidentalis occurs mostly on the Canary
Islands (Spain), but according to Baum (1977) can
be also found on the continent in Portugal, Egypt,
I.G. Loskutov and H.W. Rines
Ethiopia, as well as on the Azores and on Madeira
Island, though initially it had been described in course
of processing herbarium material from Algeria. The
species tends to grow on alluvial soils in valleys and
on stony slopes (Durieu de Maisonneuve 1845; Baum
1971).
Therefore, wild Avena species occupy vast areas in
the basins of the Mediterranean, Black, and Caspian
seas and demonstrate a wide range of genetic diversity
and good adaptation to different ecogeographical and
soil conditions of the regions.
A detailed morphological description and study of
features of this or that oat species helps to define
precisely its systematic position within a complicated
system of the entire genus showing different ploidy
levels and the huge morphological diversity determined by the vast natural habitat occupied by wild,
weedy, and cultivated species.
3.1.1.3 Karyotype and Cytology of Avena
Species
Quite often, karyological analyses of cultivated plants
and their wild relatives confirm their taxonomic status at the interspecific levels, thus making genomic
characterization of the material in question possible.
Karyological and cytological studies of Avena L. species have a long history (Avdulov 1931; Huskins
1927; Nikolaeva 1922; Rajhathy and Thomas 1974)
(Table 3.2).
Diploid Species with C Genomes
The widest karyotype diversity is found within
diploid oat species. All of them split into three
groups: those containing predominantly subterminal
Table 3.2 The karyotype structure of Avena species
Species
Genome
Type of chromosomesa
SMt2
STt2
SMt1
A. bruhnsiana
Cv
–
–
1
A. ventricosa
Cv
–
–
1
A. clauda
Cp
1
–
1
A. pilosa
Cp
1
–
1
A. prostrata
Ap
1
–
1
A. damascena
Ad
1
–
1
A. longiglumis
Al
1
–
1
A. canariensis
Ac
1
–
1
A. strigosa
As
1
–
1
A. hirtula
As
1
–
1
A. wiestii
As
1
–
1
A. atlantica
As
1
–
1
A. barbata
AB
1
–
1
A. vaviloviana
AB
1
–
1
A. abyssinica
AB
1
–
1
A. agadiriana
AB?
–
–
2
A. magna
AC
1
1
1
A. murphyi
AC
1
–
1
A. insularis
AC?
1
–
1
A. macrostachya
CC?
–
2
–
A. fatua
ACD
1
–
2
A. sativa
ACD
1
–
2
A. byzantina
ACD
1
–
2
A. sterilis
ACD
1
–
2
A. ludoviciana
ACD
1
–
2
A. occidentalis
ACD
1
–
2
Reference
M
–
–
–
–
3
4
4
4
2
2
2
2
4
4
4
2
4
4
4
10
4
4
4
4
4
4
SM
1
–
–
–
1
1
1
1
2
2
2
2
6
6
6
7
2
6
7
–
7
7
7
7
7
7
ST
5
6
5
5
1
–
–
–
1
1
1
1
2
2
2
3
5
2
1
2
7
7
7
7
7
7
Emme (1932)
Rajhathy (1961)
Nikolaeva (1922)
Nikolaeva (1922)
Ladizinsky (1971b)
Rajhathy and Baum (1972)
Malzev (1930)
Baum et al. (1973)
Kihara (1919)
Huskins (1926)
Huskins (1926)
Baum and Fedak (1985a)
Kihara (1919)
Emme (1932)
Aase and Powers (1926)
Baum and Fedak (1985b)
Murphy et al. (1968)
Ladizinsky (1971a)
Ladizinsky (1998)
Baum and Rajhathy (1976)
Kihara (1919)
Kihara (1919)
Kihara (1919)
Kihara (1919)
Huskins (1926)
Baum (1971)
M median chromosomes; SM submedian, ST subterminal, SMt1, SMt2, STt2 satellite chromosomes with different type of satellites
(t1 large satellite, t2 small satellite)
a
3 Avena
chromosomes (A. ventricosa, A. bruhnsiana, A. clauda,
and A. pilosa), the species with one pair of such
chromosomes (A. prostrata, A. wiestii, A. hirtula,
A. atlantica, and A. strigosa), and those with only
median and submedian chromosomes (A. damascena,
A. longiglumis, and A. canariensis).
A. ventricosa and A. bruhnsiana have been determined as diploid species with the somatic chromosome number equal to 14 (Emme 1932). Numerous
studies have shown that A. ventricosa has the Av type
of nuclear genome being similar in some features with
A. pilosa (Rajhathy 1961, 1963). Later on, modification of the A. ventricosa genome relative to the clauda–
pilosa complex has been confirmed (Thomas 1970) and
underlined by assigning the Cv symbol to the A. ventricosa genome (Rajhathy 1966, 1971b). A study of an
A. bruhnsiana population from the VIR collection
revealed that all forms of this species collected in
Azerbaijan possess five subterminal chromosome pairs
(Loskutov 2007) as has been observed in an earlier
investigation (Rajhathy 1971b). On the basis of similarity of submedian chromosomes, the species A. ventricosa and A. bruhnsiana have been identified as the very
primitive ones in the Avena section (Rajhathy and
Thomas 1974).
A study of another pair of closely related diploid
species, A. clauda and A. pilosa, has found them to have
similar karyotypes (Nikolaeva 1922; Emme 1932). An
analysis of karyotypes of the species has shown that
the presence of two pairs of satellite chromosomes and
five of medium subterminal chromosome pairs in the
karyotype may be regarded as their main character. On
the basis of karyological analysis, the genome formula
of A. pilosa and A. clauda was changed from previously
suggested Ap (Rajhathy 1966) to Cp and the species
were defined as primitive ones in the Avena section
(Rajhathy and Thomas 1974).
The differences between these genomes confirm
the rule deduced for the diploid species karyotypes
(Thomas 1992), the essence of which is that the differences in the morphology of chromosomes in diploids
are mainly in the position of the centromere and secondary constrictions. At the same time, all the abovementioned species with the asymmetric karyotype are
not primitive in the true sense of the word; they are
only archaic, i.e., undergoing evolution at a slower
bradytelic type (Stebbins 1971).
The diploid Cp and Cv genome species were
studied using C-banding and fluorescence in situ
hybridization (FISH). Species with the C genome
differed considerably from the species of the A genome
group in the karyotype structure, heterochromatin
type and distribution, and position of 5S and 45S
rDNA loci. These facts confirmed that the C genome
had diverged from the ancestral genome before the
radiation of the various A genome group. Presumably,
further evolution of the A- and C-genome species
occurred separately (Shelukhina et al. 2008b).
Diploid Species with A Genomes
The number of chromosomes in somatic cells of A.
longiglumis is 14 (Malzev 1930) that was later confirmed by other researchers (Holden 1966). A study of
different populations of this species revealed that the
early flowering short-stem forms had two pairs
of satellites, while the late flowering tall forms had
just one pair (Morikawa 1992). Some researchers
believe the genome of this species to be similar to
that of A. strigosa (Steer et al. 1970), while others
think it is different (Griffiths et al. 1959). The genome
had been designated as Al (Rajhathy and Morrison
1959), and later, the difference of the genome of this
species from other variants of A genome has been
confirmed by a variety of other methods (Rajhathy
1961; Thomas and Jones 1965; Murray et al. 1970).
Chromosome number and karyotype structure were
determined for A. prostrata (Ladizinsky 1971b), and
its genome was designated as Ap (Rajhathy and Baum
1972).
The number of chromosomes of A. damascena is
14 (Rajhathy and Baum 1972). Its karyotype (designated as Ad) resembles that of A. longiglumis very
much with the only difference in the ratio (1:1)
between the large satellite and the chromosome
arm to which it is attached (Rajhathy and Thomas
1974). On the other hand, later evidence indicated
that this species occupied a unique position in the
A-genome diploid species based on the pattern of in
situ hybridization with rDNA probes (Shelukhina
2008).
A. canariensis was shown to be a diploid species
(Baum et al. 1973). The karyotype of this species (Ac)
is similar to the Al (A. longiglumis) and Ad (A. damascena) karyotypes with the only difference being one
satellite slightly larger. This species was supposed to
be the A genome donor for hexaploid oats (Baum et al.
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I.G. Loskutov and H.W. Rines
1973) and for the AC-genome tetraploid species
(Leggett 1980). Different populations of this species
had different numbers of satellited chromosomes. The
early flowering population from Lanzarote Island
(Spain) was found to have just one chromosome pair
with a satellite, while the late flowering populations
had two pairs of SAT chromosomes (Morikawa and
Leggett 1990). The diploid oat species containing the
Al and Ac genomes were studied by C-banding and in
situ hybridization. Their karyotypes displayed similar
C-banding patterns but differed in size and morphology of several chromosomes, presumably because of
structural rearrangements that occurred during the
divergence of A genomes from a common progenitor.
A considerable similarity of A. canariensis and A.
longiglumis to Avena diploid species carrying the As
genome variant was demonstrated (Shelukhina et al.
2008a).
The chromosomes number of cultivated A. strigosa
is 2n ¼ 14 (Kihara 1919). The karyotype of this
species was characteristic of the whole diploid sandy
oats group that included A. hirtula and A. wiestii with
the As genome (Huskins 1926; Emme 1932; Shepeleva
1939; Rajhathy 1961), though initially the former species had been grouped with the tetraploids (Huskins
1926, 1927). A study of the A. wiestii karyotype and its
comparison with the A genome of hexaploid species
had initially confirmed their similarity (Holden 1966;
Thomas and Thomas 1970), and its partial structural
modification has been proved by a number of authors
(Sadanaga et al. 1968). A cytogenetic investigation of
the As-genome species has displayed significant closeness of A. strigosa and A. weistii and a somewhat
isolated position of A. hirtula in this group. The results
of this investigation contradict the findings of other
authors that the rearrangement of chromosome 7 is
species-specific to A. strigosa because all three studied
species (as well as A. hispanica) are similar morphologically as well as in terms of the chromosome
C-banding pattern (Badaeva et al. 2005).
Later-discovered species A. atlantica, with the
number of chromosomes in somatic cells 2n ¼ 14,
had a similar karyotype as the As genome (Baum and
Fedak 1985a), though its plants differed very much
morphologically from other species in this group. A.
strigosa-specific carried a chromosomal translocation
relative to the diploid species A. atlantica and A. hirtula
(Loarce et al. 2002).
Tetraploid Species with CC Genomes
A. macrostachya, the most primitive perennial outcrossing species, has been identified as an autotetraploid (2n ¼ 28). It has a symmetrical karyotype mainly
with median chromosomes, which differ little in size
and represent a gradually decreasing series in terms of
length. The presence of a large number of chromosomes, which are similar in terms of size and structure,
favor its autotetraploid nature. Cytologically, the
nature of this species has been confirmed by behavior
of chromosomes in meiosis. On the average, 56.6%
of chromosomes formed quadrivalents, which is
characteristic of the majority of autotetraploids in
the Poaceae family (Baum and Rajhathy 1976). A
symmetrical karyotype is not characteristic of the
C-genome diploid species (Pohler and Hoppe 1991),
but at the same time, this character brings A. macrostachya closer to the A-genome oat species (Loskutov
2001b). The presence of large C-heterochromatic
blocks in the chromosomes’ pericentromeric regions
indicates similarity between this and the C-genome
species and it is supposed that this species can have
the hitherto undescribed CmCm genome (Rodionov
et al. 2005). At the same time, the karyotype symmetry suggests its primitive nature, being confirmed by
outcrossing, perennial type of development, and a
complex of morphological and cytological characteristics. According to Levitsky’s (1976) results in
1931 obtained and those of Stebbins (1971) perfectly
symmetrical karyotype is an indicative of species
primitiveness.
Tetraploid Species with AB Genomes
Morphologically, karyotypes of tetraploid species are
subdivided into two groups that have two distinctively
different genomes. In the first place, the studies of
tetraploid species refer to the chromosome number
analysis in the wild species A. barbata (Kihara 1919;
Emme 1932; Shepeleva 1939). Morphologically, chromosomes of the tetraploid species differ somewhat
from those of the diploid species belonging to the
strigosa group, and the AsAb formula has been used
to designate their karyotype (Holden 1966). On the
other hand, the genome of this group of species has
been designated as AB (Ladizinsky 1973b) as it was
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3 Avena
determined earlier that the A genome of the tetraploid
species was similar to the As genome of the diploid
ones (Ladizinsky and Zohary 1968). A similarity of
the main karyotypic features with other tetraploid species with AB-genomes has been confirmed by many
researchers (Rajhathy and Morrison 1959; Thomas
and Thomas 1970). This group includes two Ethiopian
endemics: A. vaviloviana, a wild species (Emme
1932), and cultivated A. abyssinica (Aase and Powers
1926; Emme 1932). All these species have one and the
same karyotype and AB genome composition.
The recently discovered species A. agadiriana has
been classified as tetraploid (Baum and Fedak 1985b).
Its karyotype does not resemble those of any other
tetraploids (Baum and Fedak 1985b), still its genome
is presumed to be AB (Leggett 1988), though this
species has an absolutely different morphological
structure of lodicules and of the lemma tip. A study
of different populations of this species has shown the
early flowering forms to have three pairs of satellited
chromosomes, while the late flowering ones had only
two (Morikawa 1991, 1992).
The tetraploids A. abyssinica, A. vaviloviana,
A. barbata, and A. agadiriana have been studied
using C-banding and in situ hybridization, which confirmed affiliation of all the four species with the AB
genome group and demonstrated significant isolation
of A. agadiriana. A supposition has been made that
A. abyssinica, A. vaviloviana, and A. barbata had
originated from a common tetraploid progenitor:
however, the species diverged due to structural chromosome rearrangements and changes in the polymorphism system. Phylogenetic closeness has been
demonstrated of the A and B genomes of these species
to the A-genome diploids. The most probable progenitor of the A genome for A. abyssinica, A. vaviloviana,
and A. barbata is an As-genome species. The second
diploid progenitor of these three species has not been
identified, but most likely, it does not belong to the Asgenome group. Diploid progenitors of A. agadiriana
also have not been established; however, it is supposed
that A. damascenа could be one of them (Shelukhina
et al. 2009). FISH and Southern hybridization were
used to investigate the chromosomal distribution and
genomic organization of tetraploids. The study indicates that the Ethiopian endemic species A. abyssinica
and A. vaviloviana have diverged from A. barbata.
Differences between A. barbata and A. vaviloviana
genomes were also revealed by both FISH and Southern
hybridization using pAs120a rDNA probes. Whereas
two B-genome chromosome pairs were found to be
involved in intergenomic translocations in A. vaviloviana, FISH detected no intergenomic rearrangements in
A. barbata (Irigoyen et al. 2001).
Tetraploid Species with AC Genomes
A. magna (Murphy et al. 1968) and A. murphyi
(Ladizinsky 1971a, d) represent the second group of
tetraploid species. It has been established that the
karyotype of A. magna differs from those of other
tetraploid species and does not contain the B genome
(Murphy et al. 1968). Later, this genome was designated as AC instead of the previously determined
AD genome (Murray et al. 1970). A cytogenetic analysis of A. magna and A. barbata hybrids has found
these species to have little relation to each other
(Thomas 1988). Further study showed that the karyotype of A. murphyi has a somewhat different structure
(Rajhathy and Thomas 1974), though this species
also have the AC genome (Rajhathy and Thomas
1974).
Another tetraploid species, A. insularis, is morphologically very similar to the above-mentioned group.
The species was not found to contain the A genome
(Ladizinsky 1999): presumably, this species contains
either AC or CD genome. Crosses between A. insularis populations collected on Sicily and in Tunisia
gave partially sterile hybrids, confirming their genetic
remoteness (Ladizinsky and Jellen 2003). Evaluation
of A. insularis C-banding karyotype showed that the
Sicilian wild tetraploid is a close relative of A. magna
and A. murphyi and is more plausible than either of
these two species as the immediate tetraploid progenitor of A. sterilis and the other hexaploid oats (Jellen
and Ladizinsky 2000).
A comparative cytogenetic investigation of three
tetraploid species A. magna, A. murphyi, and A. insularis has shown these species to be similar in terms of
C-banding patterns of a number of chromosomes.
According to the data obtained, A. insularis is phylogenetically closer to A. magna, while A. murphyi is
somewhat isolated from two other species. It may be
supposed that all of the three studied species have a
common tetraploid progenitor and their divergence is
associated with different species-specific chromosome rearrangements. Apparently, the evolution of
I.G. Loskutov and H.W. Rines
A. murphyi proceeded independently from other species (Shelukhina et al. 2007).
Hexaploid Species
Hexaploid species have similar karyotypes and in
general have the same genome composition. Investigations of these species started by determining chromosome numbers for A. fatua, A. sterilis (Kihara
1919; Emme 1932), and A. ludoviciana (Huskins
1926). Eighteen chromosome pairs of hexaploid
A. sativa and A. fatua were morphologically similar,
while three pairs showed very different morphology
(Shepeleva 1939). Later on, it was determined that
such karyotype structure is typical for hexaploids.
A. fatua, A. sterilis, A. byzantina, and A. sativa have
been found to possess the same ACD genome composition (Rajhathy and Morrison 1959; Rajhathy
1966). Initially, the genome was designated as ABC
(Nishiyama 1929), but then, the genome formula
was changed to ACD (Rajhathy and Morrison 1959;
Rajhathy 1963). It has been later supposed that A
genome was the Ac genome of the diploid A. canariensis (Thomas and Leggett 1974), while the Cv
genome of the diploid A. bruhnsiana was the source
of the C genome (Rajhathy 1966). However, similarity of the As genome to the A genome of hexaploid
species has not been confirmed (Ladizinsky 1969).
A cytogenetic study of populations of wild Mediterranean species concluded that A. pilosa (Cp) and
the A. strigosa (As) group are the basic variants of the
C and A genomes, respectively, while other species
(A. ventricosa (Cv) and A. longiglumis (Al)) have
structurally altered derivative karyotypes (Rajhathy
1963).
On the contrary, a study of the AB genome of the
tetraploid A. barbata did not identify it as a progenitor
of the hexaploid species (Thomas et al. 1975).
Thus, the modern karyological and cytological
investigations make it possible to identify chromosomes in a karyotype and thus provide the possibility
of making a judgment about intraspecific and genomic
differences at the chromosomal level. Therefore, the
karyotypic peculiarities characterizing individual species facilitate a better understanding of the position of
each species in the system of genus Avena and help to
elucidate taxonomic problems.
3.1.1.4 Agricultural Status of Wild Oat Species
Some Avena species are truly wild and grow in natural
habitats on different types of soils, and some of them
are weeds. They comprise noxious weeds in agricultural fields such as A. fatua and A. sterilis, including
the well-known A. ludoviciana and A. barbata, and
truly wild plants as native components of their local
flora as A. clauda, A. pilosa, A, ventricosa, A. prostrate, A. damascena, A. hirtula, A. wiestii, A. canariensis, A. atlantica, A. murphyi, A. agadiriana, A.
insularis, etc. (see Sect. 3.1.1.2).
All oat species prefer in general a temperate hot,
semi-arid and dry climate; in the east, they prefer
temperate semi-arid or temperate arid climate and do
not grow in hot and dry climates. For diploid and
tetraploid species, a combination of favorable climate
types in the African continent occurs in some regions
of Morocco, Algeria, and coastal regions of Tunisia in
the north, and Ethiopia in the east. In the European
continent, this combination is offered by the southern
Europe, especially Spain, Mediterranean islands, as
well as coastal and mountainous territories of the
Black and Caspian sea basins. In the Asian continent,
favorable climates may be found in Israel, Jordan,
Syria, Turkey, Azerbaijan, northern parts of Iraq,
Iran, and Afghanistan, and Central Asian states, and
it is here that some of the diverse species of oat are
found. Hexaploid species A. sterilis and A. ludoviciana
grow in the same territories and occupy wider areas
to the south and north of the natural habitat. A. fatua
has a wider natural habitat, which encompasses all
European countries up to the northern ones as well as
territories of Russia, Mongolia, and China. This species has never occurred below the 25th parallel in the
Asian continent. In the African continent, this species
occupies the entire northern part and reaches as far
as Ethiopia and northern Kenya in the east. A. barbata,
A. ludoviciana, A. sterilis, and A. fatua occur as adventitious species in most regions of the American continent, on the southern tip of Africa, in New Zealand,
and Australia (see Sect. 3.1.1.2).
The the economic importance of the wild diploid
species such as A. clauda and A. pilosa occurring in
arid semi-deserts in the Caucasus and A. canariensis
growing in the Canaries (Spain) is not great as they
have limited value as forage for cattle (Grossheim
1967; Morikawa and Leggett 1990); however, the
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3 Avena
nutritive value of another tetraploid species, A. barbata,
is of special importance for breeding. The hybrids produced in Japan exceed standard cultivars by 15–40%
in terms of total green mass yield. In the US, the latter
species is regarded as a promising forage (Marshall
and Jain 1968, 1970; Coffman et al. 1970). According
to a number of explorers, the hexaploid species
A. fatua and A. ludoviciana represent a fairly good
pasture forage in the Caucasus and Southern Russia
and are promising for green fodder crop breeding and
use for fodder purposes (Roshevitz 1934; Grossheim
1967; Musaev et al. 1976). A thorough study of local
populations of A. sterilis applying different methods
was carried out in California with the aim of involving
them in fodder crop breeding (Singh et al. 1973). In
India, A. strigosa, A. magna, A. sterilis, and A. fatua
are widely used for breeding fodder cultivars (Choube
et al. 1985).
Thus, on the one hand, wild oat species are noxious weeds of agricultural crops, while on the other,
they can be used as natural forages for agricultural
purposes.
3.2 Conservation Initiatives
3.2.1 Evaluation of Genetic Erosion
at Space and Time Scale
Population growth, urbanization, developmental pressures on the land resources, deforestation, changes in
land use patterns, and natural disasters are contributing
to abundant habitat fragmentation and destruction
of the crops and their wild relatives. Social disruptions or wars also pose a constant threat of genetic
wipeout of such promising diversity. Overexploitation
and also the introduction of invasive alien species are
the other factors contributing to the loss of genetic
resources. More recently, global warming and a high
degree of pollution have also been recognized as further causes for the loss of biodiversity (Hammer and
Teklu 2008).
Genetic diversity among domestic lines or cultivars
is always more restricted than that of the parents or the
general plant population(s) from which the cultivars
originated. As improvements are made through further
recombination and selection among progenies, genetic
diversity narrows even more. When the oat crop was
developed from the original wild species, early agriculturists selected successive individual plants over a
long time on the basis of favorable appearance, seed or
green forage production or both under cultivation, and
personal preferences of those who harvested and saved
seed for replanting. Each primitive cultivar had less
genetic diversity than the source population or the
species (Wesenberg et al. 1992).
Loss of such diversity is critical because it could be
a source of pest resistance or adaptive characters not
recognized at the time. Loss of genetic diversity associated with oat domestication and other species, however, dwarfs the loss of genetic diversity that modern
plant breeders have been responsible for in the process
of cultivar development. Thus, a continuing effort is
required to conserve most wild Avena populations, old
landraces, and populations; otherwise they will be lost
forever.
Two types of genetic erosion can be distinguished
in wild populations: the extinction of populations
and the drastic change of genetic structure of populations. The first type means the total loss of genetic
resources, which results from complete destruction of
habitats, and all genotypes and/or alleles being lost,
while the second one originates from isolated local
populations due to the deterioration of habitats. In
another case, there is significant risk of the ultimate
loss of diversity because smaller populations are vulnerable to demographics and the decline in fitness
associated with genetic drift and inbreeding. Genetic
drift is the random change in allele frequency that
occurs because gametes transmitted from one generation to the next carry only a sample of the alleles
present in the parental generation (Hammer and
Teklu 2008).
The threatened wild oat species and those with a
shrinking natural habitat include A. clauda, A. pilosa,
A. ventricosa, A. bruhnsiana, A. damascena, A. prostrata, A. canariensis, A. atlantica, A. agadiriana,
A. magna, A. murphyi, A. insularis, and A. occidentalis. All these species represent components of natural
habitats in some countries on the Mediterranean
coast of Africa, southern coast of Spain, Italy, Greece,
and a part of Mediterranean and Atlantic islands.
Most natural habitats are disjunctive due to the island
location of habitats; therefore, the species are narrow
endemic in the outlined area. At present, natural habitats of these species are shrinking because of the
I.G. Loskutov and H.W. Rines
anthropogenic pressure. Apparently, the abovementioned species once had wide natural habitats.
For instance, Malzev (1930) noted in his work that
in the early twentieth century, A. ventricosa used to
be widely spread in Algeria and in Cyprus, while at
present, the natural habitat of this species is very
narrow, with single plants occurring in these regions.
According to researchers who recently have been
collecting A. bruhnsiana, in the Apsheron Peninsula
(Azerbaijan), this species is disappearing at high rate,
most likely because of activities of oil development
and construction companies in this territory (Loskutov
2007). The endemic diploid species A. canariensis
occurs only within a limited area of the Canaries
(Spain); another tetraploid species (A. agadiriana),
isolated from that diploid and resembling it morphologically, is distributed in a very narrow range near
Agadir in Morocco. According to Spanish and Moroccan researchers, genetic diversity of the tetraploid
species A. murphyi has sharply decreased in comparison with the results of previous collecting, and in some
places, it could not be found at all (Perez de la Vega
et al. 1998; Saidi and Ladizinsky 2005). The recently
described new tetraploid species A. insularis, which
has been discovered in both Italy (Sicily) and Tunisia,
also has a very narrow natural habitat. Of special
importance is the most primitive oat species – the
perennial outcrossing tetraploid A. macrostahya. This
narrow endemic species has been found at the very
edge of snows (1,500 m) in the mountainous regions of
Djurdjura and Aures (the Atlas Mountains) in northeastern Algeria only. Apparently, all the above-listed
species are losing a part of their habitats, and some
genotypes and/or alleles are being lost; other species
may experience genetic erosion as a result of genetic
drift and inbreeding caused by the shrinkage or split of
natural habitats, or the decrease in plant number in a
certain territory.
The problem of genetic erosion through inappropriate maintenance of ex situ collections is widely recognized. Genetic erosion can occur at many stages in the
preparation, subsampling, exchange, storage, and
regeneration of seed samples (Sackville Hamilton
and Chorlton 1997). These authors also highlighted
loss of diversity through genetic shifts and convergent
selection during regeneration as a potentially severe
and often underacknowledged problem. However, the
different institutes are suffering from financial problems, lack of staff, and shortage of farms.
The threat of loss of genetic integrity from regeneration of wild oat species is very high. The reason is
that practically all Avena species originate from the
Mediterranean and adjacent regions, while the ex situ
collections are maintained predominantly in countries
that are quite distant from the regions of collection and
natural habitats. As a result, regeneration of these
species in the regions where the genebanks conserving
these accessions are located may lead to genetic shifts
and convergent selection during regeneration. Lengthening of regeneration backlogs due to inadequate
funding, lack of technical staff, and its low proficiency
causes partial loss of germination by seed material,
which, in turn, leads to the loss of genetic integrity of
the non-regenerated accessions. The long-term storage
strongly reduces the metabolism and therefore highly
limits viability and seed vigor. In this case, poor germination potential and vigor in the field also are indicators of genetic erosion.
Another important problem complicating regeneration of accessions and experienced by genebanks
around the world in their work with wild oat species
is the absence of distinct descriptors based on clearly
visible and easily distinguishable morphological characters, which could be used for the identification of
botanical diversity using morphological characters
of the plant in the field and morphological characters
of the kernels in the laboratory. On the whole, these
problems may lead to genetic erosion of individual
accessions even if they are under careful conservation
and safety-duplication.
3.2.2 Attempts of In Situ and Ex Situ
Conservation
The conservation of plant diversity is of critical importance because of the direct benefits to humanity that
can arise from its exploitation in improved agricultural
and horticultural crops, because of the potential for
development of new medicinal and other products and
because of the pivotal role played by plants in the
functioning of all natural ecosystems (Hammer and
Teklu 2008).
In formulating strategies for the conservation of
any crop, it is essential to know areas of distribution
and identify regions where its collecting for conservation activities could usefully be initiated. This will
3 Avena
be due to a combination of high levels of genetic
diversity at the site(s), interest of the user community
in the specific genetic diversity found at or believed to
be found at the site, lack of previous conservation
activities, and imminent threat of genetic erosion
(Maxted et al. 1997).
There are two primary complementary conservation strategies, ex situ and in situ, each of which
includes a range of different techniques that can be
implemented to achieve the aim of the strategy. The
products of conservation activities are primarily conserved germplasm, live and dried plants, cultures,
and conservation data. The conservation materials
are either maintained in their original environment
or deposited in a range of ex situ storage facilities.
To ensure safety, conservation products should be
maintained at more than one location (Hammer and
Teklu 2008).
The great genetic diversity to be found in the traditional agriculture stocks in the centers of genetic
diversity, where the wild or weedy relatives of crop
species can be found, were called gene centers or
centers of origin according to Vavilov (1926) and
centers of diversity according to Harlan (1975).
As agriculture progressed with the beginning of
scientific plant breeding, modern varieties were
widely distributed replacing landraces from cultivation. This increased the need to formally store plants
and seeds in ex situ collections. Landraces were then
gathered together, which resulted in fairly large collections, above all in the US and in Russia. The great
Russian biologist N. I. Vavilov accumulated rich collections of diversity in the Institute of Plant Industry
(now VIR) by systematically collecting material
(Loskutov 1999).
Wild species are much more difficult to maintain
and to regenerate than the cultivated forms. Their
safeguard is a major concern in the oat community.
As the convention of biological diversity (CBD) and
the International Treaty (IT) reinforce the national
sovereignty on biological diversity, centers of diversity will need primary consideration in developing a
global conservation strategy, also with respect to complementary actions of ex situ and in situ conservation.
Such a complementary approach will not only
increase the security of the conserved material, but it
will also allow evolutionary processes to continue, use
the safest conservation strategies, and facilitate a
closer link between the more scientific orientated and
static ex situ approach with the much more practically
orientated and dynamic in situ conservation. In addition, it is expected that this complementary approach
will also result in an improvement of the quality of
conservation and of the knowledge of the existence of
genetic material as well as in more transparency.
These factors increase the possibility to integrate the
various conservation strategies and to make use of the
material collaboration, also through exchange, independently from where the material is located (ECPGR
2008).
Among the various ex situ conservation methods,
seed storage is the most convenient for long-term
conservation of plant genetic resources. Traditionally,
many crops are conserved as seed in gene banks. This
involves desiccation of seeds to low moisture contents
and storage at low temperature. The ex situ conservation of large numbers of cultivated plants depends on
the longevity of the seeds. Most species belong to the
orthodox seed type with a logarithmical progression of
shelf-life as humidity and storage temperature are
reduced (Hammer and Teklu 2008).
The recently established Global Crop Diversity
Trust has begun contributing to the development of
regional and global crop-specific strategies aimed at
more effective arrangements for ex situ conservation
(www.croptrust.org). The Global Strategy for the ex
situ conservation for oats was discussed at the meeting
of genebank curators and stakeholders of oat in St.
Petersburg in 2007.
Ex situ conservation of wild oat species has
provided fairly good results. Some of these species,
especially hexaploid ones, can retain their germinating
ability for 10–15 years at room temperature. Under
controlled conditions, at þ4 С, 10 С, or 18 С and
standard humidity, seeds of these species keep viability well and therefore retain genetic integrity for a long
period. Unfortunately, until now, no research has been
undertaken by genebanks to elucidate the influence of
duration of different types of ex situ storage facilities
on the oat species genetic integrity. Judging from the
data on genetic integrity of oat landraces conserved at
VIR in ex situ storage facilities for the last 80 years, a
positive conclusion about genetic stability of the studied material can be made (Zelenskaya et al. 2004).
In situ conservation is defined as the conservation
of ecosystems and natural habitats, and the maintenance and recovery of viable populations of species in their natural surroundings, and, in the case of
I.G. Loskutov and H.W. Rines
domesticated or cultivated species, in the surroundings
where they have developed their distinctive properties.
The first decision concerning the establishment of a
nature reserve for the in situ conservation of cereal
species in Ethiopia was taken at the First International
Wheat Congress in Rome in April 1927 following the
N.I. Vavilov’s report entitled “Les centres mondiaux
des genes du ble,” in which he formulated preliminary
results of his collecting mission to Ethiopia (Loskutov
1999). Over 50 years had passed before this method of
genetic diversity preservation was adopted by the
international community.
In situ conservation activities should be carried out
for saving wild oat species, some of which are quite
rapidly disappearing from Earth. Unfortunately,
according to the Spanish researchers, only vegetation
of the Canaries can at present be regarded as relatively
protected from destruction, thanks to the ban on
human activities expansion in effect on the islands.
Among the species growing there are A. canariensis
and A. occidentalis. At present, an EU project for the
in situ conservation of the species of special importance for cultivated oat breeding (A. magna, A. murphyi and A. insularis) is being developed for
implementation in Morocco, Spain, Italy, and Tunisia.
3.2.3 Germplasm Banks: National and
International
About 220,000 oat accessions in ex situ collections
have been estimated in the state of the world’s plant
genetic resources report. Large collections are held by
the USDA (20,000 accessions), the PGRC, Canada
(30,000 accessions), and within the framework of the
ECP/GR (34,146 accessions), namely by the Vavilov
Institute of Plant Industry (VIR, Russia) (about 12,000
accessions), which has a collection of about 10,000
accessions of four cultivated and 2,000 accessions of
21 wild species (Loskutov 2001b). For those 90,000
accessions, documentation is easily accessible on the
internet. Further, large collections have been mentioned by FAO in Kenya (13,000 accessions), in Israel
(7,500 accessions), the latter announcing an especially
rich collection of A. sterilis (5,000 accessions), and in
Australia (Germeier 2008).
In FAO/WIEWS (http://apps3.fao.org/wiews/
germplasm.htm), 29 collections are listed that maintain accessions of wild Avena species (Table 3.3) of
which 13 hold more than 20 respective accessions
(Brazil, Canada, China, Germany, Israel, Morocco,
Norway, Poland, Russia, Spain, Sweden, UK, USA).
Some genebanks accumulate specific and geographic diversity of wild oat species not only by
means of natural collection but also through seed
exchange with and ordering samples from other genebanks (Tables 3.4 and 3.5). This way, they managed to
accumulate quite a wide diversity of these species.
These genebanks are located in USA, Canada, Russia,
Germany, Great Britain, and Poland. Other genebanks,
such as those in Australia, Israel, Turkey, Brazil, and
some other countries, have the mandate to collect and
conserve national biodiversity including wild species
that occur in these territories. Therefore, they possess
small collections of the species in question. It should
be noted that hexaploid species, A. sterilis (A. ludoviciana) and A. fatua, in the first place represent the
Table 3.3 Number of accessions of wild oat species in the main genebanks (Germeier 2008)
Institution
Country
Agriculture and Agri-Food Canada, Plant Gene Resources of Canada, Saskatoon Research Center
USDA-ARS, National Small Grains Germplasm Research Facility
N.I. Vavilov Research Institute of Plant Industry
Tel-Aviv University Institute Cereal Crop Development Lieberman Germplasm Bank
Agricultural Research Center, Australian Winter Cereals Collection
Aegean Agricultural Research Institute, Department of Plant Genetic Resources
Institute for Plant Genetics and Crop Plant Research – Genebank
National Wheat Research Center
National Plant Genetic Resources Center Plant Breeding and Acclimatization Institute
Agricultural Research Organization, Volcani Center, Israel Gene Bank for Agricultural Crops
Canada
USA
Russia
Israel
Australia
Turkey
Germany
Brazil
Poland
Israel
Number
of accesions
14,935
10,908
2,001
1,544
549
311
300
254
168
117
AU8
3 Avena
Table 3.4 Representation of wild Avena species in ex situ
collections in the world (Germeier 2008)
Species
Number of accessions
A. atlantica
18
A. brevis
87
A. canariensis
70
A. damascena
17
A. hirtula
75
A. hispanica
16
A. longiglumis
85
A. nuda
35
A. prostrata
2
A. strigosa
697
A. wiestii
76
A. bruhnsiana
1
A. clauda
111
A. pilosa (syn. A. eriantha)
156
A. ventricosa
8
A. macrostachya
13
A. abyssinica
615
A. barbata
2,526
A. lusitanica
30
A. vaviloviana
248
A. agadiriana
18
A. insularis
14
A. magna (syn. A. moroccana)
97
A. murphyi
12
A. diffusa
8
A. fatua
2,341
A. hybrida
24
A. ludoviciana
444
A. macrocarpa
2
A. occidentalis
71
A. sterilis
22,951
main part of wild oat accessions in the ex situ collections because they are of great importance as breeding
material and are easy to conserve and propagate in the
field (Table 3.5). Other species, especially the diploid
ones, are rare in genebank collections as their natural
ranges are narrower, their diversity is sufficiently
smaller, and because most of them are difficult to
distinguish from each other, and their conservation
and propagation are very laborious. In this respect,
the Canadian genebank is quite unique with its collection of oat species founded by B. Baum, who has been
collecting oats worldwide in the 1970s–1980s (Baum
et al. 1975). The American genebank maintains a
small collection of diploid and tetraploid species;
VIR (Russia) conserves a diverse collection of these
species; small collections are also preserved in
Germany and Poland. Besides, a small, very carefully
composed unique collection of diploid and tetraploid
species of oats is conserved in the Welsh Plant Breeding Station, University College of Wales (UK). The
base of this collection is seed of Avena wild species
obtained during Canada–Wales Expeditions (Rajhathy
et al. 1964). Basically, this collection was assembled
for research rather than practical purposes for studying
cytogenetics and genomic interactions between wild
oat species (Leggett 1992a).
Genebanks can employ standard methods of ex situ
conservation, but organizationally they may differ.
Two types of national genebanks exist, the centralized
and decentralized ones. Genebanks of the first type
unify management of all the plant genetic resource
(PGR) activities within one single center (institution),
while the stations, where collections are studied and
regenerated, can be located elsewhere (Russia, Germany, Canada, etc.). The decentralized genebanks
consist of a National PGR Council that coordinates
activities of individual institutions and stations where
different collections are conserved, studied, and regenerated (USA, France, Spain, etc.).
The institutions with a long-standing history of
PGR activities belong to the group of centralized genebanks, while the recently established ones, especially
those in the West-European countries, belong to the
decentralized organizations.
United States’ National Plant Germplasm System.
Initially in 1898, at the Department of Agriculture of
US was established the Section of Seed and Plant
Introduction. Later on, the National Plant Germplasm
System (NPGS) was organized. It constitutes a coordinated group of scientists from Federal, State,
and private sectors of the US agricultural research
community. Responsibilities include (1) the acquisition, maintenance, evaluation, enhancement, and distribution of a broad array of germplasm, (2) research
on the preservation of genetic diversity and methods
of preserving viability through improved storage procedures, and (3) monitoring of genetic vulnerability
(Wesenberg et al. 1992).
The key elements of the NPGS pertinent to oat
include:
1. USDA-ARS Plant Science Institute, Beltsville Agricultural Research Center, Beltsville, MD. This
includes the Plant Introduction Office, the Germplasm Services Laboratory, the Germplasm Quality
Enhancement Laboratory, and the Systematic
Botany and Nematology Laboratory. Included in
AU9
Table 3.5 Representation of wild Avena species in the main ex situ collections (Germeier 2008)
Genebank atlantica canariensis dama‐ hirtula longi‐ wiestii clauda pilosa ventri‐ macro‐ barbata vavilo‐ agadiriana insularis magna murphyi fatua hybrida ludovi‐ sterilis
scena
glumis
cosa
stachya
viana
ciana
Canada
USA
Russia
Australia
Germany
Poland
Israel
Turkey
Brazil
15
45
3
51
13
45
7
12
46
4
15
2
17
5
9
5
1
10
5
6
7
5
5
1
7
1
91
13
132
4
12
5
1
3
1
1
10
6
6
2
1,685
611
90
40
3
10
32
50
135
43
46
22
14
3
2
34
2
16
2
1
4
4
8
34
1
2
1
3
579
23
1,322 1
219
7
96
1
20
71
1
434
4
11,461
8,246
833
536
65
37
1,500
204
52
I.G. Loskutov and H.W. Rines
3 Avena
the Germplasm Services Laboratory is the Germplasm Resources Information Network (GRIN)
Database Management Unit.
2. USDA-ARS National Seed Storage Laboratory
(NSSL), Fort Collins, CO. The NSSL, established
in 1958, is the only long-term storage facility in
the US for crop germplasm normally maintained
through seed.
3. USDA-ARS National Small Grains Germplasm
Research Facility, Aberdeen, ID. The NSGC is
housed in the USDA-ARS National Small Grains
Germplasm Research Facility that was completed
in 1988 at the University of Idaho Aberdeen
Research and Extension Center, Aberdeen, ID
(Wesenberg et al. 1992). This is main storage
for all cereal crops and for cultivated and wild
oat too.
Nearly one-half of the NSGC oat germplasm consists of wild Avena species, primarily A. sterilis and
A. fatua. Since the latter two are hexaploids and can
be crossed readily with A. sativa, they are currently
the most useful of the related species. Adequate
diversity is probably represented in the A. sterilis
accessions obtained from Israel, but not from other
regions of the world. There is inadequate diversity
represented by the accessions available in the NSGC
for most other wild species, including some diploids
and tetraploids (Wesenberg et al. 1992). GRIN provides National Genetic Resources Program (NGRP)
personnel and germplasm users continuous access
to databases for the maintenance of passport, characterization, evaluation, inventory, and distribution data
important for the effective management and utilization of national germplasm collections (http://www.
ars-grin.gov/).
Plant Gene Resources of Canada. Agriculture and
Agri-Food Canada appointed the first Plant Gene
Resources officer and established Plant Gene
Resources of Canada (PGRC) in 1970. Until early
1998, it was located at the Central Experimental
Farm in Ottawa, but moved to a modern facility in
Saskatoon. Canada’s Plant Germplasm System is a
network of centers and people dedicated to preserving
the genetic diversity of crop plants, their wild relatives, and unique plants in the Canadian biodiversity.
The system plays a significant part of Agriculture and
Agri-Food Canada’s commitment to the Canadian
Biodiveristy Strategy in response to the Convention
on Biological Diversity. The largest wild oat collection in the world is located there.
A multinodal system was established in 1992 to
respond to the recommendations from study committees on the enhancement of germplasm conservation
in Canada. It was initially funded through the Green
Plan. This initiative links rejuvenation, evaluation,
and documentation to research and plant breeding
programs for specific crop plants. Seed storage facilities at PGRC consist of long-term, medium-term
and cryopreservation units. For long-term storage, a
large walk-in vault is available in which seed is
preserved in laminated envelopes at 20 C. For
medium-term storage, a large walk-in vault stores
seed in paper envelopes at 4 C and 20% relative
humidity. Seeds are evaluated for viability, dried to
optimum moisture content of 6–8% and transferred
to either medium- or long-term storage. Cryopreservation (a type of freezing) in or over liquid nitrogen
at 196 C is the most highly developed of these
techniques. Depending on the species, dry seeds can
last from a few years to probably centuries (http://
pgrc3.agr.gc.ca/index_e.html).
Vavilov Institute of Plant Industry – VIR (Russia)
originated and developed from the Bureau of Applied
Botany organized in 1894; in 1930, it was named the
All-Union Research Institute of Plant Industry (VIR –
Russian abbreviation), and since 1967, it has borne the
name of N.I. Vavilov. The main directions in the work
of the Institute were determined by N.I. Vavilov to be
collecting, conserving, studying, and utilizing plant
genetic resources. Besides, the Institute is involved
in designing methods for studying collection materials
and developing various long-term conservation techniques. The Vavilov Institute of Plant Industry is governed by the administration (located in St. Petersburg)
that supervises and coordinates activities of the entire
institute and experiment stations, including nine
departments of crop genetic resources, the Department
of Agrobotany, and In Situ Conservation with a unique
herbarium collection, ten departments and laboratories
dealing with methodology of PGR studies, a genebank
consisting of several storage facilities (ensuring PGR
conservation at þ4 C, 10 C, 18 C and cryoconservation), and the Department of Biotechnology
that includes an in vitro conservation unit. The
network of the Institute also includes 11 experimental
stations for PGR studies and regeneration, and the
I.G. Loskutov and H.W. Rines
National Seed Store at Kuban Experiment Station
(þ4 C, 10 C, 18 C).
On the VIR website, more information about Institute’s activity and passport database of VIR collection
is available (http://vir.nw.ru/data/dbf.htm). VIR collection of cultivated and wild oat is maintained in the
Department of Genetic Resources of oat, barley, and
rye. All information about taxonomy, characterization,
evaluation, and breeding value of cultivated and wild
species collection is available on their Avena webpage
(http://vir.nw.ru/avena/).
Coordination activities of national genebanks are
fulfilled by international organizations. The International Board for Plant Genetic Resources (IBPGR)
was established in 1974 to create and coordinate a
worldwide network of germplasm resource conservation centers. The IBPGR receives funds from the
World Bank, the Food and Agriculture Organization
of the United Nations (FAO), the United Nations
Development Program, and individual donor nations.
Like other international centers for agricultural
research, the IBPGR is under the jurisdiction of the
Consultative Group on International Agricultural
Research (CGIAR), established in 1971. The Board’s
Secretariat, responsible for collecting and documenting information and administering the Board’s financial program, is provided by the FAO in Rome. The
IBPGR has been effective in assisting various international, regional, and national research centers in
acquiring, multiplying, storing, documenting, evaluating, and distributing germplasm. The IBPGR or its
designees have established a set of descriptors for
many crop species, organized and sponsored collection expeditions, and designated specific locations as
repositories for the world’s base collections for seed
of principal food crops. In 1991, IBPGR was renamed
as International Plant Genetic Recourses Institute
(IPGRI). IPGRI is an autonomous international scientific organization, supported by the CGIAR. Mandate
of the Institute is to advance the conservation and use
of plant genetic resources for the benefit of present and
future generations. In 2006, IPGRI and the International Network for the Improvement of Banana and
Plantain (INIBAP) became a single organization
under new name Bioversity International (http://www.
bioversityinternational.org).
Collection centers participate in national, regional,
and global networks. National networks in many cases
organize the national plans and responsibilities on
genetic resources and often have to coordinate a
multitude of institutions working in the sector.
Important regional networks are the ECP/GR on the
European level and related activities as EURISCO
and the Central Crop Database. Information networking in the Nordic countries is affiliated with SESTO,
a genebank management tool developed by the
Nordic Gene Bank. In South America, some networking has been mentioned around the software product
DBGermo. Global networks cover breeding interests, such as the Quaker nursery and a Uniform Oat
Winter Hardiness Nursery, the FAO World Information and Early Warning System (WIEWS), and several international information projects such as the
Global Biodiversity Information Facility (GBIF)
and the Pedigree of Oatlines (POOL) database.
Though GRIN is a national product of the USDA, it
is of global relevance and is also used by Canada, and
thus considered as an international network. A large
part of networking focuses on information and documentation issues (Germeier 2008).
The Working Group on Avena was set up in 1984
with the task of coordinating the work on oat genetic
resources in Europe (IBPGR 1984). The Group unites
oat collection curators from all European genebanks.
The Working Group coordinates activities aimed at
collecting, documenting, studying, conserving, and
utilizing oat genetic resources. A large part of networking focuses on information and documentation
issues through Avena Database (http://eadb.bafz.de/
bgrc/eadb/avena.htm). Periodically, the Group convenes its meetings to discuss the most important questions related to genebank activities (IBPGR 1986,
1989; Frison et al. 1993; Maggioni et al. 1998). At
present, the Avena Working Group operates within the
ECPGR Cereals Network that coordinates the work on
genetic resources of all cereal crops in the European
territory as well as that performed by the institutions
holding significant cereal collections in some Asian
and African countries (Lipman et al. 2005; Maggioni
et al. 2009) (http://www.ecpgr.cgiar.org/Workgroups/
avena/avena.htm).
At present, genebanks and international organizations involved in activities targeted at oat genetic
resources conservation successfully perform and coordinate this work aimed at rational and effective utilization of oat species in breeding programs.
3 Avena
3.2.4 Modes of Preservation and
Maintenance: Seeds/Propagule/
Cryopreservation
The limited amount of genetic variation for vegetatively propagated species has led to efforts to develop
in vitro conservation methods. It guarantees freedom
from pest infestation and diseases. However, it is
extremely laborious and cost intensive and can therefore only be used for special material as a long-term
storage possibility (Hammer and Teklu 2008).
Cryoconservation is accomplished with liquid
nitrogen at 196 C. It is also suitable for seeds and
leads to a dramatic prolongation of germination rates.
It allows for an extremely long storage of many species. The problem with cryoconservation is its high
cost, especially for technical equipment. A constant
supply of liquid nitrogen also has to be available at all
times (Hammer and Teklu 2008).
In regard to seeds of wild oat species, some experimental work concerning their cryoconservation was
carried out at VIR (Russia) in the 1970s–1980s but
was terminated later, as the procedure for seeds of
this type turned out to be unjustifiably expensive in
comparison with conservation under different storage
regimes ensuring good germinating ability of oat seeds
for a long period.
3.3 Role in Elucidation of Origin and
Evolution of Allied Crop Plants
Combined field studies performed in the late 1950s
and early 1960s in the regions of the origin and maximum diversity of oat species Avena (Baum et al.
1972a, b; Rajhathy et al. 1964, 1966) drew attention
of the researchers to the karyology and cytogenetics
of cultivated oat species and their wild relatives. This
added to understanding the mechanisms responsible
for reproductive isolation of the species. Since the
1950s, the investigation of wild and cultivated oat
species has involved interspecific crosses conducted
for various purposes (Rajhathy and Thomas 1974).
The theoretical objective of these studies was to establish the diploid ancestor of cultivated hexaploid oat,
which, in turn, would add to understanding the cytogenetics of this species and clarify its genomic formula
and pathway of evolution.
One of the first studies concerning the genomic
formula of cultivated oat was performed by Nishiyama
(1929), who crossed A. sativa and A. strigosa. In later
experiments, crosses of A. strigosa with the diploid
species A. hirtula and A. wiestii produced fertile
offsprings, and their chromosomes were completely
homeologous. This suggested that these species
belong to one group having the same genome, thereby
confirming Malzev’s (1930) suggestion on close relatedness of these forms, which he assigned to one
species A. strigosa. It was found that these species
are identical in chromosome structure because their
hybrids regularly formed seven bivalents (Rajhathy
1966).
The diploid species A. atlantica was crossed with
A. strigosa and other species of this group and gave
fertile progeny. On this ground, some authors regarded
A. atlantica as a wild analog of A. strigosa instead of
A. hirtula (Rajhathy and Morrison 1959).
Other diploid species having chromosome variants
of the A genome [A. canariensis (Ac), A. damascena
(Ad), A. prostrata (Ap), and A. longiglumis (Al)] differ by the results of hybridization: A. prostrata is
quite compatible with all the listed species, and A. longiglumis is readily crossable with A. strigosa, whereas
hybrids between A. canariensis and A. damascenа
are sterile (Rajhathy and Morrison 1959; Rajhathy
1961; Rajhathy and Baum 1972; Baum et al. 1973;
Ladizinsky 1973a; Leggett 1984, 1987). On the other
hand, A. strigosa, A. hirtula, A. wiestii, and A. atlantica have similar karyotype and are interfertile.
A. lusitanica, A. hispanica, and A. matritensis have
been demonstrated to be homologous to A. strigosa
according to results of DNA in situ hybridization.
A. longiglumis and A. prostrata are more related to
each other than to A. strigosa, from which they differ by at least five chromosome rearrangements.
A. damascena and A. canariensis are separate from
A. strigosa with at least three translocations; a larger one
is in A. canariensis and assume a common progenitor
for A. damascena, A. canariensis, and A. prostrata
(Jellen and Leggett 2006).
Crosses of the diploid species A. pilosa with
cultivated oat revealed partial chromosome homeology for one of these species genomes. A high or
I.G. Loskutov and H.W. Rines
complete homeology was revealed in crosses between
the A genome diploid species and hexaploid species.
However, these species are incompatible in crosses
with A. pilosa. It was thus concluded that A. pilosa
has a variant of the C genome (Rajhathy 1966). Species with the C genome are readily crossed with each
other and their hybrids form seven bivalents. At the
same time, no interspecific hybrids were obtained
between the species with the genomic formulas A
and C. The species A. ventricosa was generally used
in such studies as the donor of the C genome (Rajhathy
and Thomas 1967). The natural habitat of this species
(Algeria and Cyprus) is completely isolated from
those of species with the A genome, which confirms
their incompatibility. The scarcity of bivalents in the
meiosis of the A. strigosa A. pilosa hybrid carrying the A and C genomes confirmed the significant
difference between these genomes (Nishiyama and
Yabuno 1975).
The results of cytogenetic studies of C genome
species are consistent with the suggestion by Malzev
(1930), who pointed to a significant difference in the
ecology and morphology of these taxa and recognized
two groups of diploid species, A. pilosa, A. clauda and
A. ventricosa, A. bruhnsiana. The species of the former group gave fertile offspring in crosses with each
other (Rajhathy and Thomas 1967; Nishiyama and
Yabuno 1975) and demonstrated reproductive isolation in crosses with the species of the latter group.
Interspecific crosses between diploid species and
species with other ploidy levels demonstrated that the
A genome could have been originated from A. strigosa
and A. longiglumis (Rajhathy 1971a) or A. canariensis
(Baum et al. 1973). Only partial homeology was
revealed between the chromosomes of A-genome diploids and those of cultivated oat (Rajhathy and Thomas
1974). The morphological traits of A. canariensis suggested that it could have been the progenitor of tetraploid and hexaploid species (Baum et al. 1973), but
cytological studies did not reveal complete homeology
between their chromosomes (Leggett 1980). Afterwards the A genome developed independently from
the C genome, which brought about lots of A genome
variants (Al, Ap, Ad, Ac, As), and finally produced a
cultivated diploid species (A. strigosa) with the As
genome (Loskutov 2008).
On the basis of ample factual evidence, it was
suggested that A. ventricosa could have been the
diploid donor of the C genome for tetraploid and
hexaploid species (Rajhathy 1966). All tetraploid species can be classified into four groups based on their
karyotypes, morphology, and the pattern of chromosome conjugation in meiosis of interspecific hybrids.
Group 1 includes A. barbata, A. vaviloviana, and
A. аbyssinica. They are genetically uniform and possess the AB genome. Their relationships were later
confirmed by the fact that the tetraploid species of
this group are autotetraploids, which originated from
the diploid species A. hirtula and A. wiestii (Holden
1966; Ladizinsky and Zohary 1968; Sadasivaiah and
Rajhathy 1968). The AB genome was suggested to
have resulted from the divergence of the original diploid A genome (Rajhathy and Thomas 1974). In recent
studies, it is designated as AA0 (Fabijanski et al. 1990).
These species are readily crossable with all species
of the genus Avena, except for diploids with the
C genome (Leggett and Markland 1995). Both tetraploid species from this group A. vaviloviana and
A. abyssinica, having found in Ethiopia the most
favorable climate and soil conditions for distribution
into the south of the Mediterranean center, were
unable to move further because of more severe arid
climate in the countries adjacent to Ethiopia. It should
be mentioned that diploid and hexaploid cultivated
species incorporate naked forms, while tetraploids
do not contain them. The most probable reason for
that, in our opinion, is that the species of this group
were unable to disperse far from their center of origin
and had no recessive mutations (Loskutov 2008).
The species with A and AB (AA0 ) genomes and a
biaristulate lemma tip in most cases each floret disarticulated. Some of them have cultivated analog with
the same ploidy level (A. wiestii, A. hirtula – A. strigosa; A. vaviloviana – A. abyssinica) and wider areas
of distribution (A. wiestii, A. hirtula, A. barbata, etc.)
being rather active weeds. Obviously, this group
apparently had no part in the development of hexaploid oats (Loskutov 2008).
Group 2 includes A. magna and A. murphyi. Crossing of diploid species possessing the As genome with
A. magna gave partially sterile hybrids (Leggett 1987).
Cytological examination of the F1 hybrids from A.
barbata A. magna showed that these species are
not related. Crosses A. sativa A. magna also yielded
sterile F1 hybrids (Thomas 1988). The great morphological similarity between A. magna and wild hexaploids and the meiotic pattern of pentaploid hybrids
obtained with the use of A. sativa suggested that
AU10
3 Avena
A. magna could have been involved in the evolution of
hexaploid species as an AC tetraploid progenitor
(Ladizinsky and Zohary 1971).
Reciprocal crosses of A. magna with cultivated
oat and other hexaploid species demonstrated its
important role in the evolution of hexaploid species
(Ladizinsky 1988). The results of interspecific crosses
brought some scientists to the conclusion that the
tetraploids bearing the AC genomes originated from
diploid species bearing its components, presumably
A. canariensis (A) and A. ventricosa (C). According
to an alternative opinion, the A genomes of A. magna
and A. strigosa were identical, and the C genomes of
A. magna and A. pilosa were related. However, later,
this hypothesis was discarded (Leggett and Markland
1995; Leggett 1998).
Group 3 of tetraploids includes A. macrostachya,
which is a perennial outcrossing autotetraploid.
According to Malzev’s (1930) definition for the
genus Avena, the morphological features of this
species allow it to be assigned to the most primitive
oat-grasses. Crosses of this species with diploids
possessing various derivatives of the A genome
(A. damascena, A. prostrata, A. atlantica, and A. canariensis) demonstrate negligible chromosome homeology (Leggett 1985, 1992b). According to other
studies, the most viable F1 hybrids were obtained
between A. pilosa and A. macrostachya. They often
form trivalents in the metaphase. Hybrids between
A. atlantica and A. prostrata formed seven bivalents
each (Pohler and Hoppe 1991). The mitosis study of
crosses A. barbata A. macrostachya suggested
autotetraploid origin of the latter and the close relatedness of the species, although the hybrids were sterile
even after chromosome duplication by colchicine
(Hoppe and Pohler 1989).
The apparent differences in the morphology of
A. macrostachya and a low percentage of chromosome
conjugation in the meiosis of hybrids of A. macrostachya with A. sativa and A. murphyi indicate that
A. macrostachya was not involved in the evolution
of tetraploid or hexaploid species (Leggett 1985).
Further studies demonstrated that the A. macrostachya
genome is closer to the C (A. pilosa) genome than to
the A (A. strigosa) one (Leggett 1990).
A. macrostachya is considered as more related to
the C-genome than the A-genome diploids and the
situation may be complicated by the operation of a
pairing control gene in the species (Jellen and Leggett
2006). It is the only autotetraploid species within the
genus Avena (Rodionov et al. 2005), while all other
tetraploid species are a result of hybridization of different diploid progenitors (Badaeva et al. 2005).
Meanwhile, according to Rodionov et al. (2005),
the division of the phylogenetic oat lines carrying A
and C genomes was accompanied by accumulation of
differences in dispersed repeat sequences and accumulation of transitions and transversions specific for each
branch. Later, the C-genome line segregated into phylogenetic branches of A. macrostachya from the progenitor of the other species with the C genome, and
after that, the progenitors of A. macrostachya doubled
their chromosome number and generated large blocks
of C-heterochromatin that resulted in characteristic
C-banding pattern of A. macrostachya chromosomes.
Group 4, including A. agadiriana, cannot be considered as independent since this species is little studied. A. agadiriana was discovered by finding
tetraploid forms in collections of the diploid species
A. canariensis rather than discovering it in nature.
Later, it was found that these species have different
natural habitats: the diploid A. canariensis is endemic
to Canary Islands (Spain) and the tetraploid A. agadiriana occurs only in Morocco (Baum and Fedak
1985a, b). Nevertheless, it is believed that the latter
is more closely related to A. barbata than any other
tetraploid species and has the AB genome composition
(Leggett 1988). Moreover, A. agadiriana is similar to
A. magna, A. murphyi, and other hexaploids in the
structure of lodicules, forms of lemma tips, etc. The
participation of A. agadiriana in the evolution of hexaploids is indicated by the above evidence and by the
good crossability between hexaploids and this species
(Thomas 1988; Alicchio et al. 1995).
Interspecific crosses were also used for determining
the genomic constitution of the most important group
of hexaploids. Crosses of diploid species having the
As genome (A. strigosa group) and tetraploid species
having the AB genome with A. sativa demonstrated
that the hexaploid species has the A genome but lacks
the B genome. In later studies, the A and C genomes
were found to be similar to the corresponding genomes
of diploids and tetraploids, whereas the origin of the D
genome is still unknown (Rajhathy and Thomas 1974).
The following evolutionary pathway was proposed:
A. canariensis > A. magna > A. sterilis (Baum et al.
1973). Later, the A genomes of A. magna and
A. sterilis proved to be closer to each other than the
AU11
I.G. Loskutov and H.W. Rines
A genomes of A. abyssinica and A. sativa. It was suggested that A. magna was the donor of two genomes
(AC) of the hexaploid Avena species (Thomas 1988).
Later, it was found that the genomes A and D are
similar to each other but different from C (Leggett and
Markland 1995). The A genome of the diploid progenitor appears to have been the ancestor of the A and D
genomes of hexaploid species (Linares et al. 1996).
Recent studies have demonstrated that the D genome
is likely to be a variant of the “A” genome, like the B
genome, but differs from the latter (Leggett 1997). On
the other hand, Katsiotis et al. (2000) reported on repetitive DNA elements common to Arrhenatherum and the
Avena A genome that were either absent, less abundant,
or polymorphic in the C genome of Avena.
A new tetraploid species, A. insularis, has been
recently reported in 1998. It was suggested to be one
of the progenitors of the hexaploid species and is
tentatively assumed to have the CD or CA genome.
This species gave fertile hybrids with A. strigosa only.
With closely related A. magna and A. murphyi, the
hybrids were sterile and partially fertile hybrids are
obtained with hexaploid species (Ladizinsky 1999).
Species with C and AC genomes (A. ventricosa,
A. canariensis, A. magna, A. murphyi, A. insularis) are
considered as transitional progenitor forms in the evolution of hexaploid oats (Fig. 3.1). Some of these
species are strictly endemic or have a very limited
area of distribution as wild representatives of natural
undisturbed habitats. There are no other (direct)
cultivated analogs of these species. Together with the
cultivated forms, these species are classified into a
section Avenae (Loskutov 2008).
In Avena, areas of domestication seem not to coincide with the primary areas of distribution or the
centers of origin of the weed progenitors (Vavilov
1965a, 1992). Malzev (1930) located the origin of
the hexaploid oat in Southwest Asia region. Baum
(1972) considered A. septentrionalis (¼ A. hybrida)
as the closest progenitor to the cultivated oat. It is
distributed in Mongolia to the Ural links the European
center with the Chinese centers of diversity of
cultivated oats (Holden 1979; Thomas 1995).
The species A. sterilis is a more likely hexaploid
progenitor of cultivated oat than A. fatua (Zhou et al.
1999; Jellen and Beard 2000). It is suggested that
large-seeded A. sterilis, disarticulated by separate spikelets, underwent mutations in the type of floret dispersal, which led to the development of the cultivated
species A. byzantina, and on the other hand, of the wild
species A. occidentalis shattering by separate florets
and occurring presently only on the Canary Isles
(Spain). It is highly probable that, owing to the
changes in the disarticulation type, A. occidentalis
had previously occupied vast areas; besides, its dominating type of development is winter or semi-winter,
and we consider it as primary, compared to the spring
type. In the process of eastward distribution, A. sterilis
became differentiated into more adaptive smallseeded forms of A. ludoviciana, which underwent
mutations in the Minor Asiatic center that changed
their florets’ disarticulation type. It led, in turn, to the
appearance of weedy forms of A. sativa. As for A.
occidentalis, when moving eastwards, it acquired earlier-ripening, typically spring forms, which combined
into a separate species, A. fatua (may be included A.
hybrida). This species, disarticulating by separate florets, became a harmful weed and infested vast areas in
the north and east of Europe and Asia. Weak sensitivity to vernalization and strong reaction to the length of
day was reported to indicate true spring nature of A.
fatua, which enabled it to occupy by weeding the most
extensive agricultural territories on Earth. True spring
nature of this species proves that it was secondary in
origin as compared with A. sterilis and A. ludoviciana
(Loskutov 2007).
The ample evidence on interspecific crosses and
other researches suggest that the evolution of the
genus Avena involved two strikingly different genomes: A and C. Other genomes were their more or
less distant derivatives. According to the generally
adopted assumption that the diploid species A. canariensis and A. ventricosa are the progenitors of the A
and C genomes, respectively, the evolution of the
resulting allopolyploids should have involved structural chromosome rearrangements, making them partially homeologous.
3.3.1 List of Related Crop Plants
The cultivated hexaploid common oat ranks fifth
among cereals in world production. Oats are coolseason crop, and while they are grown to some
extent on every continent, their production is of far
greater importance in the cool climate of the northern
hemisphere.
3 Avena
ssp.nudibrevis
ssp.nudisativa
A.occidentalis - ACD
A.vaviloviana-AB
A.sativa - ACD
A.barbata - AB
A.hirtula - As
A.agadiriana – AB?
A.wiestii - As
A.ludoviciana - ACD
A.murphyi - AC
A.byzantina - ACD
A.sterilis - ACD
A.strigosa-As
A.magna - AC
A.canariensis - Ac
A.atlantica - As
A.insularis–CD?
A.clauda - Cp
A.bruhnsiana - Cv
A.pilosa - Cp
A.prostrata - Ap
A.ventricosa - Cv
A.damascena - Ad
A.longiglumis - Al
Avenastrum
- evolution pathways of the species and forms
- probable evolution pathway of hexaploid cultivated species
Fig. 3.1 Phylogenetic relationships of Avena species (Loskutov 2008). Thin arrow: evolution pathways of the species and forms,
bold arrow: probable evolution pathway of hexaploid cultivated species
Avena is a polyploid series from diploid through
tetraploid to hexaploid. There are cultivated forms
at each ploidy level: the common oat (A. sativa, 2n ¼
6x ¼ 42), the red oat (A. byzantina, 2n ¼ 6x ¼ 42), the
Ethiopian oat (A. abyssinica, 2n ¼ 4x ¼ 28), and
the sandy oat (A. strigosa, 2n ¼ 2x ¼ 14). The
whole diversity of cultivated oats was proven by
N. I. Vavilov (1926) to have a weedy field origin. As
its species moved northwards, oat replaced basic crops
by weeding them and became an independent crop for
itself. This process may be clearly traced in Spain on
the cultivated diploid species A. strigosa, in Ethiopia
on A. abyssinica, in Turkey and Iran on A. byzantina,
and in Iran and Russia on A. sativa (Fig. 3.2). The
main difference between wild species and cultivated
ones is disarticulation of the florets. All cultivated
species have non-shattering panicle, mostly glabrous
lemma and soft awn if it existed. Very high distribution of cultivated, especially hexaploid, species through
the whole world is a reason for their high diversity
(Loskutov 2008).
The hexaploid cultivated species A. sativa occurs in
all agricultural regions of the world with moderate
climate; it is cultivated in all European countries
including Russia, in the north of the Asian continent,
above the 30th parallel, in the North American
countries, in the northern and southern parts of South
America, at the southern tip of Africa, in New Zealand,
and Australia. This species is represented by both
hulled (A. sativa subsp. sativa L.) and naked forms
(A. sativa subsp. nudisativa (Husnot.) Rod. et Sold.)
(Rodionova et al. 1994), which, to all appearance,
have originated in China (Loskutov 2008) (Fig. 3.2).
The species A. byzantina has a more limited natural
habitat and is characterized by a higher degree of drought
tolerance. It is cultivated in countries of Southern
Europe, in northern Africa, in Southwest Asia above
the 30th parallel, and in some South American
countries. Under cultivation, this species is represented
by hulled form only [A. byzantina (С. Koch) Thell.],
while the existence of a naked form [A. byzantina
subsp. denudate (Hausskn.) Rod. et Sold.] has been
This figure will be printed in b/w
A.fatua - ACD
A.abyssinica -AB
I.G. Loskutov and H.W. Rines
subsp. nudibrevis
3
A. sativa
6
A. strigosa
subs. nudisativa
2
A. sativa
7
A. byzantina
subs. denudata
5
A. abyssinica
4
1. Mediterranean centre – Morocco, Algeria, Spain
5. South-West Asian centre – Turkey, Iran, Iraq, Syria
2. Spain and Portugal – centre of diversity of A. strigosa
6. Tatarstan, Bashkortostan – diversity of A. sativa convar. volgensis
3. Great Britain – centre of diversity of A. strigosa subsp. nudibrevis
7. China, Mongolia – centre of diversity of A. sativa subsp.nudisativa
4. Abyssinian centre – Ethiopia, centre of diversity of A. abyssinica
- pathways of distribution of cultivated species and forms.
Fig. 3.2 Evolution pathways of cultivated Avena species (Loskutov 2008)
identified by Malzev (1930) and mentioned by Rodionova et al. (1994). Recently, it has also been newly
described and confirmed of Turkish origin (Loskutov
2007) (Fig. 3.2). It should be noted that the majority
of modern oat cultivars widely spread in Southern
Europe, Asia, Africa, America, and Australia have
originated as hybrids of A. sativa and A. byzantina
with an intermediate manifestation of many morphological traits.
A. abyssinica is a tetraploid species typical of
Ethiopia, which had progressed northwards to more
humid regions, crowded out other cereal crops (e.g.,
barley), and had become a cultivated plant. In the
south of the country, it is an ordinary segetal weed in
spelt and barley fields (Vavilov 1965b, 1992). Most
likely, the species has not developed naked forms
because of the narrowness of its natural range. The
diploid A. strigosa has been quite widely cultivated for
forage and hay before Second World War in many
countries of northern and Central Europe as well as
in the European Russia. At present, this species is a
ruderal weed in Southern Europe and in some places
is cultivated for non-commercial use (Fig. 3.2). At
the same time, such commercial cultivars of this
species as Saia, Saia 2, Saia 4, Saia 6, etc. have
been bred in Brazil through selection from local
populations and are cultivated quite widely in South
America. In the nature and majority of collections,
this species is represented by hulled forms (A. strigosa subsp. strigosa Thell. and A. strigosa subsp.
brevis Husn.), which, most likely, have originated
from Spain, but sometimes unique naked forms originating from the mountainous regions of Great
Britain may be found, which had been described by
Linneaus (1762) as A. nuda L. In the beginning of the
twentieth century, the name A. nuda L. started to be
used for the naked forms of diploid cultivated
oats, while the diploid forms were given the name
A. nudibrevis Vav. In the 1970s, B. Baum (1977)
restored the initial name A. nuda L. to the diploid
naked forms, but the hexaploid naked forms were not
determined in this taxonomy. On the other hand, it
has been proved long ago that the diploid naked
forms are easily crossed with the hulled forms of
A. strigosa Schreb., and this pair has much in common concerning the majority of morphological traits.
This figure will be printed in b/w
A. byzantina
1
AU12
3 Avena
According to Rodionova et al. (1994), these naked
forms belong to the sandy oat subspecies A. strigosa
subsp. nudibrevis (Vav.) Kobyl. et Rod.
Thus, the genus Avena includes four cultivated
species, which had been quite widely used in agriculture of different countries of the Old World, while at
present only cultivated hexaploid oat species keep
leading positions in the world in terms of the occupied
areas.
3.3.2 Application of Morpho-taxonomy
Classification based primarily on morphological traits
is the fundamental basis for botanical research. There
is no agreement among researchers regarding the systematics of the species in Avena L. The history of
taxonomy of this genus started about 300 years ago
(Linneaus 1762, 1753). Among the numerous publications of the nineteenth century dedicated to the
systematics of Avena L., the most significant taxonomic surveys were by Marshall Bieberstein (1819),
Grisebach (1844), Koch (1848), and Cosson and Durie
de Maisonneuve (1855). Natural or phylogenetic classifications that outlined groups of related species and
derived cultivated species from wild ones were developed later (Jessen 1863; Haussknecht 1885). Similar
views on the polyphyletic origin of oats were shared
by other researchers (Trabut 1909, 1914; Thellung
1911, 1919, 1928; Zade 1918).
The most detailed classification of this very important genus of Mediterranean origin was developed
by Malzev (1930) and remains the most cited Avena
monograph based on the main morphological characters – rachilla and lemma tip shape, lemma pubescence, and the disarticulation of florets. Many
assumptions concerning the position of a number of
species were made by him on the basis of analysis of a
complex of morphological and biological characteristics. Malzev produced the most comprehensive phylogenetic system of the type section of this genus based
on lemma tip characteristics by dividing it into two
subsections and by analyzing all wild species known
at that time. According to Malzev (1930), Avena
includes 7 species represented by 22 subspecies and
184 recognizable groups within subspecies (varieties
and forms). The work of Malzev drew heavily on that
of Thellung (1928). Malzev made a thorough analysis
of Avena based on the major classification principles
dominating at that time, where subspecies was an
important taxonomic unit (Table 3.6).
Further development of a natural classification for
the genus resulted from explorations of Vavilov (1926,
1927, 1992), Nevski (1934), and Mordvinkina (1936).
For the detailed structured systems of the genus, the
authors used morphological characteristics and plant
immunological data for species and subspecific taxa,
genetic and cytological data, and new information on
the natural habitats for each species. The system of
Mordvinkina (1936) supplemented by genetic, karyological, and morphological data with the addition of
newly described species served as a foundation for the
development of classification of Avena L. suggested
by Rodionova et al. (1994).
In the second part of the twentieth century, several
classifications of Avena L. were developed, for example, by Sampson (1954), Stanton (1955), Mansfeld
(1958), Coffman (1961), and Romero Zarco (1996).
Two tendencies are obvious in the modern classifications of Avena (1) a decrease in number of species
due to lumping based on karyological observations
only, and (2) an increase in the number of species
and subdivisions of species into smaller ones on the
basis of morphological differences. Extreme examples of these trends are such classifications where the
number of Avena species is either only 7 (Ladizinsky
and Zohary 1971) and 14 (Ladizinsky 1988) or 34
(Baum 1977).
In the first case, one can see unjustified lumping of
species based only on karyological data disregarding
their natural habitats. Ladizinsky (1989) combined
the whole diversity of oat forms in a number of
composite (14), so-called biological species (A. ventricosa Bal ex Coss., A. clauda Dur., A. longiglumis
Dur., A. prostrata Ladiz., A. damascena Rajhat. et
Baum, A. strigosa Schreb., A. atlantica Baum et
Fedak., A. canariensis Baum, Raj. et Samp., A. macrostachya Bal. ex Coss. et Dur., A. barbata Pott. ex Link,
A. agadiriana Baum et Fedak, A. magna Murphy et
Terrell., A. murphyi Ladiz., A. sativa L.). The remaining species are defined by him as taxonomic species
and are incorporated in the former ones without being
divided into cultivated and wild forms.
In the second case, the rank of species is attributed
to hybrid species, forms, and mutants, which evolve
quite frequently. In his researches, Baum (1974)
employed a formal approach based on the analysis of
I.G. Loskutov and H.W. Rines
Table 3.6 Taxonomic system of section Euavena Griseb. of genus Avena L. (Malzev 1930)
Subsection
Seria
Species
Subspecies
Aristulatae Malz.
Inaequaliglumis Malz.
A. clauda Dur.
A. pilosa M. B.
Stipitae Malz.
A. longiglumis Dur.
A. ventricosa Balan.
ventricosa (Balan) Malz.
bruhnsiana (Grun.) Malz.
Eubarbatae Malz.
A. strigosa Schreb.
strigosa (Schreb.) Thell.
hirtula (Lagas.) Malz.
barbata (Pott) Thell.
wiestii (Steud.) Thell.
vaviloviana Malz.
abyssinica (Hochst.) Thell.
Denticulatae Malz.
A. fatua L.
septentrionalis Malz.
nodipilosa Malz.
meridionalis Malz.
macrantha (Hack.) Malz.
fatua (L.) Thell.
sativa (L.) Thell.
cultiformis Malz.
praegravis (Kraus.) Malz.
A. sterilis L.
ludoviciana (Dur.) Gill. et Magn.
pseudo-sativa Thell.
trichophylla (C. K. et Hausskn.) Malz.
nodipubescens Malz.
macrocarpa (Monch.) Briq.
byzantina (C. K.) Thell.
AU14
variability of 27 characters by taximetric methods.
Among the most significant characters, he used the
shape (type) of lodicules and epiblast as well as the
ploidy level of the species. Both tendencies may prevent practical application of such taxonomic systems.
Baum has analyzed a very wide variety of oat materials including more than 10,000 herbarium sheets,
5,000 accessions of field evaluation, and 5,000 collected accessions of wild species. On the basis of this
exploration and evaluation, the genus Avena L. was
divided into 7 sections and 34 species (Baum 1977;
Table 3.7).
Summarized taxonomy of Malzev (1930),
Mordvinkina (1936), and Rodionova et al. (1994) and
based on the recent literature concerning the oats and
on the evaluation of the 26 species, VIR world collection of the genus Avena L. under field conditions and
different laboratory methods were confirmed. The
genus is divided up into two sections of subgenus
Avena: Aristulatae (Malz.) Losk. and Avenae Losk.
Perennial outcrossing autotetraploid A. macrostachya
belongs to subgenus Avenastrum (C. Koch) Losk. On
the basis of a detailed morphology (presence of
bidentate or bisubulate lemma tip), distribution, and
ecology (most of them true wild, not weedy species),
we concluded that diploids and tetraploids of Avenae
section were involved in the evolution of hexaploid
wild and cultivated oats (Loskutov 2007; Tables 3.8
and 3.9).
A consideration of different taxonomic systems
based predominantly on morphological traits shows
that these systems can substantially differ from each
other depending on the keystone character.
3.3.3 Application of Biochemical
and Molecular Markers
Morphological studies do not offer a complete understanding of the evolutionary and systematic position of
some oat species and forms. There is no universal
molecular approach for many of the problems faced
by taxonomists and genebank managers, and many
AU13
3 Avena
Table 3.7 Taxonomic system of species of genus Avena L.
(Baum 1977)
Section
Species
Avenatrichon (Holub)
A. macrostachya Bal. ex Coss. et
Baum
Dur.
Ventricosa Baum
A. clauda Dur.
A. eriantha Dur.
A. ventricosa Bal. ex Coss.
A. clauda eriantha F1 hybrid
Agraria Baum
A. brevis Roth
A. hispanica Ard.
A. nuda L.
A. strigosa Schreb.
Tenuicarpa Baum
A. barbata Pott ex Link
A. canariensis Baum, Rajh. et
Samp.
A. damascena Rajh. eBaum
A. hirtula Lag.
A. longiglumis Dur.
A. lusitanica Baum
A. matritensis Baum
A. wiestii Steud.
A. lusitanica longiglumis F1
hybrid
Ethiopica Baum
A. abyssinica Hochst.
A. vaviloviana (Malz.) Mordv.
A. abyssinica vaviloviana F1
hybrid
Pachycarpa Baum
A. maroccana Gdgr.
A. murphyi Ladiz.
Avena Baum
A. atherantha Presl.
A. fatua L.
A. hybrida Peterm.
A. occidentalis Dur.
A. sativa L.
A. sterilis L.
A. trichophylla C. Koch
techniques complement each other. However, some
techniques are clearly more appropriate than others
for some specific applications. In an ideal situation,
the most appropriate marker(s) can be chosen irrespective of time or funding constraints, but in other cases,
the choice of marker(s) will depend on constraints of
equipment or funds (Spooner et al. 2005). The use of
protein markers helps to sufficiently accelerate the
works on specifying genomic composition of diploid
and allopolyploid species, establishing phylogenetic
relations between the species and clarifying some
aspects of intraspecific diversity. The application of
molecular markers, proteins and DNA, has offered
possibilities for solving a series of theoretical problems related to plant phylogeny and taxonomy.
The use of protein markers permits successful identification of genetic resources and registration when
solving different problems related to classification of
cultivated plants and their wild relatives. A study of
protein markers of the cultivated hexaploid oat
A. sativa, cultivated diploid species A. strigosa, and
wild A. ventricosa has shown that out of ten bands
identified in electrophoretic banding patterns of
A. sativa, seven were found in A. strigosa and six in
A. ventricosa. At the same time, two components
identified in the latter species were missing in A. strigosa, while another found in A. sativa has not been
discovered in any diploid species. Presumably, this
component can characterize the D genome of hexaploid species (Thomas and Jones 1968). Electrophoretic banding patterns have demonstrated that the Cp
genome of diploid species probably represents the
modified Cv genome, that the C- and A-genome species have very different avenin patterns, that tetraploid
species have demonstrated sufficient diversity of this
trait, and that all the studied hexaploids had the most
monomorphic patterns (Murray et al. 1970). Later, it
was determined that diploid species with the A-genome
types had different patterns, while those with the
C-genome types were similar to each other. All the
AB-genome tetraploid species were found to be monomorphic. Both hexaploid species and individual hexaploid accessions were mostly uniform, in comparison
with other studied accessions. At the same time, all
hexaploids species and only one tetraploid species
A. magna (AC genome) were found to have identical
bands, indicating their systematic affinity (Lookhart
and Pomeranz 1985). Comparative uniformity of electrophoretic banding patterns of the AB-genome tetraploid species proves their autotetraploid nature. In
addition to affinity of the AC-genome species, closeness of the As-genome diploids to hexaploid oat species has also been proved (Ladizinsky and Johnson
1972). A study of two subspecies, A. sterilis subsp.
ludoviciana and A. sterilis subsp. macrocarpa from
Spain, has shown them to significantly differ from
one another in terms of intensity of electrophoretic
banding patterns (Cadahia and Garcia-Baudin 1978).
Out of the total of 34 bands identified in electrophoretic banding patterns, wild diploid species of
Avena were found to contain 15 bands, tetraploid 16
and hexaploid 17, on the average. The presence of
only 11–13 bands are characteristic of the C-genome
(except A. bruhnsiana), as well as Ap- and Ad-genome
AU15
Table 3.8 Key for the identification of Avena species (Loskutov 2007)
1. Perennial plants . . . . . . . . . . . . . . . . . . . . . . . . . . . A. macrostachya Balan.
Annual plants
2. Lemma tips biaristulate
Lemma tips bidentate or bisubulate
3. Glumes very unequal, lower glume one-half of upper one
Glumes equal or nearly so
4. Disarticulate each floret at maturity . . . . . . . . . . . . . . . . . . . . A. clauda Dur.
Disarticulation occurs at the lower floret only . . . . . . . . . . . . . A. pilosa M.B.
5. Disarticulate each floret at maturity or panicle non-shattering
Florets disarticulating at maturity, plant with juvenile growth prostrate
6. Glumes 40 mm long, callus very long, awl shaped, 10 mm . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. longiglumis Dur.
Glumes 10–20 mm long, callus round or absent
7. Low floret disartuculates only, callus elliptic, awn inserted at 1/3 of lemma .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. atlantica Baum
Disarticulate each floret at maturity
8.
2
3
14
4
5
6
7
Panical non-shattering
15. Disarticulate each floret at maturity
Disarticulation occurs at the lower floret only
16. Spikelets with 2–3 florets, glumes 20–25 mm long . . . . . . . . . A. fatua L.
Spikelets with 3–4 florets, glumes 15–20 mm long . . A. occidentalis Dur.
17. Callus very long, awl shaped
Callus elliptic, oval or round shaped
18. Callus 5 mm long, glumes 27–30 mm long . . . . . . . . A. ventricosa Balan.
Callus 10 mm long, glumes about 40 mm long . . . . . A. bruhnsiana Grun.
25
16
17
18
19
9
20. Spikelets small size with 2–3 florets, glumes 18–20 mm long . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. canariensis Baum et Fed.
Spikelets small size with 2 florets, glumes 15–18 mm long . . . A.
agadiriana Baum et Fedak.
21. Spikelets large size with 2 rarely 3 florets, glumes 25–30 mm long. . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A. ludoviciana Dur.
Spikelets large size with 3–5 florets
22
22. Callus round shaped
23
Callus elliptic or oval shaped
24
23. Spikelets with 3–4 florets, lemma highly pubescent . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. magna Murphy et Terr.
Spikelets V-shaped with 3–5 florets, lemma slightly-moderate pubescent .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. sterilis L.
24. Awn inserted at about one-quarter of lemma, callus oval . . . A. murphyi
Lad.
Awn inserted at lower one-third to one-half of lemma, callus elliptic . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. insularis Lad.
25. Fracture surface at the base of the primary floret is straighting . . . A. sativa
L.
Fracture surface at the base of the primary floret is slanting . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. byzantina C. Koch.
Panical non-shattering
13
Spikelets very small 12–15 mm . . . . . . . . . . . . . . . . . . . . . A. prostrata Lad.
Spikelets 20 mm long . . . . . . . . . . . . . . . . . . . . . A. damascena Raj. et Baum
10. Lemma tips biaristulate, glumes with 9–10 veins . . . . . . . . . A. barbata Pott.
Lemma tips biaristulate with 1–2 denticula or without, glumes with 7–9 veins 11
9.
11. Lemma tips biaristulate with 1 denticulum, lemma tips longer than glumes;
first floret scar narrow elliptic . . . . . . . . . . . . . . . . . . . . . . A. hirtula Lag.
Lemma tips biaristulate with 2 denticula, lemma and glumes equal or nearly 12
so; first floret scar oval
12. Lemma tips biaristulate 3–6 mm long . . . . . . . . . . . . . . . . . .A. wiestii Steud.
20
21
I.G. Loskutov and H.W. Rines
19. Spikelets small size, glumes 15–20 mm long
Spikelets large size, glumes 25–30 mm long
10
13. Lemma tips biaristulate with 1 denticulum, lemma and glumes nearly equal,
panicle equilateral or unilateral . . . . . . . . . . . . . . . . . .A. strigosa Schreb.
Lemma tips biaristulate with 2 denticula, lemma tips shorter than glumes,
panicle unilateral. . . . . . . . . . . . . . . . . . . . . . . . . . .A. abyssinica Hochst.
15
8
Disarticulate each floret at maturity
Lemma tips biaristulate 1 mm long. . . . . . . . . . . . . . . A. vaviloviana Mordv.
14. Florets disarticulating at maturity
3 Avena
Table 3.9 Speciation in the genus Avena L. (Loskutov 2007)
Section
Species
Wild
Floret disarticulation
Spikelet disarticulation
Aristulatae (Malz.)
A. clauda Dur.
A. pilosa M. B.
Losk.
A. prostrata Ladiz.
A. damascena Raj. et Baum
A. longiglumis Dur.
A. wiestii Steud.
A. atlantica Baum
A. hirtula Lagas.
A. barbata Pott.
A. vaviloviana Mordv.
Avenae Losk.
A. ventricosa Bal.
A. bruhnsiana Grun.
A. canariensis Baum
A. agadiriana Baum et Fed.
A. magna Mur. et Terr.
A. murphyi Ladiz.
A. insularis Ladiz.
A. fatua L.
A. sterilis L.
A. occidentalis Dur.
A. ludoviciana Dur.
species, the same number of bands being typical of the
monomorphic tetraploid endemic oat A. vaviloviana
(AB). The largest number of bands (over 20) is characteristic of the As-genome species and the tetraploid
oat A. barbata (AB) only. All hexaploids (ACD)
contained 18–19 bands. The number of electrophoretic
banding patterns may be connected with the degree of
distribution and adaptiveness of the given wild species
in nature. The species with the minimum number of
bands have a very limited natural habitat, while the
species with the largest number of bands and types of
electrophoretic banding patterns have quite a wide
distribution, such as, for instance, the diploids A. hirtula and A. wiestii, the tetraploid A. barbata, hexaploid
species A. ludoviciana and A. sterilis, and of course A.
fatua that weeds crop fields in the cereal belt around
the globe. In general, the data analysis has shown that
the level of polymorphism in terms of types of electrophoretic banding patterns was the highest in hexaploid species and the lowest in tetraploid and diploid
species (Loskutov 2007).
Among, other markers, a sufficient polymorphism
was discovered by an analysis of isoenzyme systems.
Definite isoenzyme loci were characteristic of different populations of A. barbata depending on the air
temperature, soil type and place of growth (Allard
1997; Perez de la Vega 1997; Guma et al. 2006).
AU16
2n
Genome
14
Cp
Ap
Ad
Al
As
28
AB
14
Cv
28
Ac
AB?
AC
Cultivated
A. strigosa Schreb.
A. abyssinica Hochst.
A. byzantina Koch
A. sativa L.
42
AC?
ACD
Although Spanish and Californian A. barbata gene
pools are closely similar in allelic composition and
allelic frequencies, large differences are in multilocus
genetic structure. Isoenzyme analysis involving 15
loci revealed 33 alleles and 38 genotypes common in
Spanish and Californian populations, 20 alleles and 45
genotypes were found only in Spain, and 2 alleles and
3 genotypes only in California. These results describe
an increasing variability and less fixed genotypes
when comparing populations from California vs.
Spain or Spain vs. Israel and southwestern Asia, the
former gene pools being more similar to each other
than to the eastern Mediterranean ones, which suggests founder effects, genetic drift, and selection during the westward distribution. A. barbata was
introduced to California by ship from Southern Spain
(Garcia et al. 1989).
Many researchers have obtained results concerning
wide intraspecific isoenzyme diversity within wild
species (Craig et al. 1974; Hoffman 1996). The largest
differences in the isoenzyme composition of oat proteins were found to exist at the interspecific level, and
the differences were stronger in species with different
genomes (Craig et al. 1972; Sanchez de la Hoz and
Forminaya 1989). Significant differences by these
traits were discovered for A. barbata and A. fatua
among the populations initially growing in the eastern
I.G. Loskutov and H.W. Rines
hemisphere and carried to the western one (Marshall
and Allard 1970; Kahler et al. 1980). The widest
diversity of the isoenzyme composition in the studied
oat accessions has been found within forms of the
diploid species A. canariensis from Fuerteventura
Island (the Canaries), if compared with populations
from Lanzarote Island in the same archipelago (Spain).
It should be noted that the isoenzyme composition
data correlated very well with the data on plant morphological traits. The differences in isoenzyme composition among populations of the same species were
stronger than between individual species and between
populations found on different continents (Morikawa
and Leggett 1990; Morikawa 1991, 1992). A similar
result was obtained from a study of the tetraploid
species A. agadiriana (Morikawa and Leggett 2005).
A study of the diversity of mitochondrial DNA
enzymes has shown that forms of A. fatua and A.
sterilis were similar or identical to those of oat cultivars (Rines et al. 1983, 1988). A study of isoenzyme
composition in a representative set of A. sterilis accessions of different geographic origin has recorded a
large diversity both for separate groups of populations
and within each group. The largest diversity has been
registered within A. sterilis populations collected in
different regions of Turkey (Phillips et al. 1993). Further studies of this trait in bred oat cultivars from USA
and Canada and in wild species have shown wild
populations to have a wider diversity compared to
cultivars (Murphy and Phillips 1993). A study of
isoenzyme composition and morphological traits of
A. sterilis populations of different geographic origin
has determined that the average coefficients of affinity between the accessions studied using various
methods were very small. Therefore, the data on isoenzyme composition cannot be completely used for
checking morphological purity of collection accessions and their genetic integrity after regeneration
(Beer et al. 1993).
The DNA marker methods, the development of
which has been recently going quite actively, are
promising for investigating polymorphism in oats.
Molecular marking of genetic systems in an organism
is based on the use of biological specificity of nucleic
acids. Restriction fragment length polymorphism
(RFLP) markers applied for mapping genome and its
loci using electrophoretic patterns has become widespread among the genetic marker techniques employing
this feature. Moreover, randomly amplified polymorphic
DNA (RAPD), amplified fragment length polymorphism (AFLP), highly variable microsatellites markers, polymorphism of ribosomal DNA, etc. are
commonly applied in botanical, genetical, and breeding research.
The RFLP, RAPD, and other marker techniques
are used for studying polymorphism in diverse materials for different purposes, for instance, for genetic
mapping and determining genetic affinity between
oat species at the DNA level (O’Donoughue et al.
1992; Van Deynze et al. 1995), for identifying alleles
of the genes controlling characters of importance for
breeding (Howarth et al. 2000), or for clarifying intraspecific variation (Hayasaki et al. 2001).
The application of DNA markers gives valid and
reliable results only when it is complemented by a
complex study of a thoroughly selected specific diversity (Heum et al. 1994; Jellen et al. 1994; Katsiotis
et al. 1996, 1997; Abbo et al. 2001).
The study of a representative set of wild A. sterilis
populations collected on both Asian and African continents was carried out by RFLP markers. The highest
genetic polymorphism was observed for the accessions collected in Iran and the lowest one for Ethiopian
accessions. Cluster analysis performed using the test
results has clearly split all populations into two
groups according to the geographic principle, that
is, from the eastern (Iran and Iraq) and western (all
other countries) regions. Besides, the second group
was subdivided into two subgroups, one including
populations of Southwest Asian origin (from Israel,
Lebanon and Syria) and the other one of African
origin (from Algeria, Morocco, and Ethiopia) (Goffreda
et al. 1992).
The questions of phylogeny and systematic position
of species are actively disputed at present time. In this
relation, the search for new approaches to solving the
problems of genome affinity and systematic position
of Avena species in genus is quite relevant. DNA
markers are promising tools to be used when carrying
out investigations in this direction, and RAPD analysis
is one of the possible research methods.
For instance, a study based on RAPD analysis has
demonstrated a possibility of distinguishing between
representatives of 20 oat species according to their
genomic composition, ploidy level, and intraspecific
differentiation. Subsequent research has confirmed the
findings (Drossou et al. 2004). Diploid species were
found to display a wider range of polymorphism in
3 Avena
comparison with the polyploid oat species. It has been
established that all the As-genome species differed
from those with the A genome types (A. atlantica,
A. longiglumis и A. canariensis). Regardless of all distinctions between these species, the data may suggest
their indirect evolutionary closeness, and this confirms
the conclusions made by other researchers on the basis
of molecular markers application (Morikawa 1992).
It should be noted that all representatives of diploid
species with the C-genome types had a low level of
similarity with the A-genome species, as well as
within their group between the Cv and Cp genomes,
thereby confirming the remoteness of both individual
genomes (A and C) and even different genome types
(Cv and Cp) from each other. The differences between
A. pilosa and A. clauda, with the same structure of the
Cp genome, were also significant, thus confirming
their remoteness and correctness for classifying them
as two separate species. Substantial differences were
characteristic of two groups of tetraploid species with
the AB (A. barbata and A. vaviloviana) and AC genomes (A. magna and A. murphyi). The degree of difference between all the species in these groups was
significant and confirmed correctness of systematic
individualization of each of them (Loskutov 2007).
Another molecular marker technique, AFLP, was
applied to screen 163 accessions of 25 Avena species
with diverse geographic origins. For each accession,
413 AFLP polymorphic bands detected by five AFLP
primer pairs were scored. All the species were clustered together according to their ploidy levels. The
C genome diploids appeared to be the most distinct,
followed by the Ac genome diploid A. canariensis.
The Ac genome seemed to be the oldest in all the
A genomes, followed by the As, Al, and Ad genomes.
The AC genome tetraploids were more related to the
ACD genome hexaploids than the AB genome tetraploids. Analysis of AFLP similarity suggested that
the AC genome tetraploid A. maroccana was likely
derived from the Cp genome diploid A. eriantha and
the As genome diploid A. wiestii and might be the
progenitor of the ACD genome hexaploids. These
AFLP patterns are significant for our understanding
of the evolutionary pathways of Avena species and
genomes, for establishing reference sets of exotic oat
germplasm and for exploring new exotic sources of
genes for oat improvement (Fu and Williams 2008).
The technique of microsatellites markers has many
desirable marker properties. According to Li et al.
(2000), using microsatellite polymorphisms, dendrograms were constructed showing not so completely
clear phylogenetic relationships among Avena species.
On the other hand, according to Fu et al. (2007), the
study attempted to characterize a structured sample of
369 accessions representing 26 countries and two specific groups with Puccinia coronata avenae (Pc) and
Puccinia graminis avenae (Pg) resistance genes using
microsatellite (SSR) markers. Analyses of the SSR
data showed the effectiveness of the stratified sampling applied in capturing countrywise SSR variation.
Accessions from Greece, Liberia, and Italy were
genetically most diverse, while accessions from
Egypt, Georgia, Ethiopia, Gibraltar, and Kenya were
most distinct. Accessions with Pc and Pg genes had
similar levels of SSR variation, did not appear to
cluster together, and were not associated with the
other representative accessions. They conclude that
these SSR patterns are significant for understanding
the progenitor species of cultivated oat, managing
A. sterilis germplasm, and exploring new sources of
genes for oat improvement.
Consensus chloroplast simple sequence repeat
(ccSSR) makers were used to assess the genetic variation and genetic relationships of Avena species. The
analysis of genetic similarity showed that diploid species with the A haplome were more diverse than other
species, and that the species with the As haplome were
more divergent than other diploid species with the A
haplome. Among the species with the C haplome,
A. clauda was more diverse than A. eriantha and
A. ventricosa. As for the maternal donors of polyploid
species based on this maternally inherited marker,
A. strigosa served as the maternal donor of some
polyploid species such as A. sativa, A. sterilis, and
A. occidentalis from Morocco. A. fatua is genetically
distinct from other hexaploid species, and A. damascena might be the A genome donor of A. fatua.
A. lusitanica served as the maternal parents during
the polyploid formation of the AACC tetraploids and
some AACCDD hexaploids (Li et al. 2009).
Later, the technique of ITS1 and ITS2 sequences
was found to be effective for taxonomic and evolutionary pathway research.
To examine the genomic constitution of A. macrostachya, the individual genes from three oat species
with AsAs karyotype (A. wiestii, A. hirtula, and
A. atlantica) and those from A. longiglumis (AlAl),
A. canariensis (AcAc), A. ventricosa (CvCv),
I.G. Loskutov and H.W. Rines
A. pilosa, and A. clauda (CpCp) were sequenced. All
species of the genus Avena examined represented a
monophyletic group, within which two branches, i.e.,
species with A- and C-genomes, were distinguished.
A. macrostachya, albeit belonging to the phylogenetic
branch of the C-genome species, has preserved an
isobrachyal karyotype, probably typical of the common Avena ancestor. It was suggested to classify
the A. macrostachya genome as a specific form of
C-genome (Rodionov et al. 2005).
C-genome clones were sequenced and the analysis
revealed close proximity to A. ventricosa ITS1-5.8SITS2 sequences, providing strong evidence of the latter’s active role in the evolution of tetraploid and
hexaploid oats. In addition, cloning and sequencing
of the chloroplast trnL intron among the most representative Avena species verified the maternal origin of
A-genome for the AACC interspecific hybrid formation, which was the genetic bridge for the establishment of cultivated hexaploid oats (Nikoloudakis and
Katsiotis 2008).
Major genic divergence between the A and C genomes was revealed, while distinction among the A and
B/D genomes was not possible. High affinity among
the AB genome tetraploids and the As genome diploid
A. lusitanica was found, while the AC genome tetraploids and ACD hexaploids were highly affiliated with
the Al genome diploid A. longiglumis (Nikoloudakis
et al. 2008).
The species and their genome relationships among
13 diploid (A and C genomes), six tetraploid (AB and
AC genomes), and five hexaploid (ACD genome) to
infer evolutionary pathways in Avena were investigated by using the plastid matK gene and the trnL-F
region and the nuclear ribosomal internal transcribed
spacers (ITS). The evaluation is presented that the B
and D genomes of Avena could be regarded as variants
of the A genome. Avena wiestii (AsAs) likely was the
maternal parent of most AACCDD species, AACC
tetraploids, and A. agadiriana (AABB). Avena hirtula
(AsAs) was the maternal parent of the other three
AABB tetraploids, and A. damascena (Ad Ad) is the
maternal parent of A. fatua. A high degree of homogenization in the ITS sequences was found, except in
A. fatua, which had two types in separate clades, one
with A genome and one with C genome carrying
species. The C genome was always differentiated
from the undifferentiated A, B, and D genomes groups
in each gene tree as well as in the tree obtained from
the three genes combined (Peng et al. 2009).
The analysis of data has demonstrated that the
different research methods involving molecular markers should not be regarded as universal tools in oat
studies; however, their correct application combined
with the use of other approaches can yield the desired
results. The undoubtful advantage provided by such
markers is in the possibility to study plant genetic
diversity right at the level of DNA, the carrier of
hereditary information. That is why these markers
have recently got a wide application for genetic mapping, analyzing plant polymorphism, phylogeny, and
taxonomy.
3.4 Role in Classical and Molecular
Genetic Studies
The most promising method of reducing genetic erosion within the cultivated species is in using wild
species along with cultivated ones in breeding activities. Practical significance of the breeding work is in
successful transfer of valuable traits from wild species
to cultivated forms. In terms of crossability, all Avena
species are grouped into three gene pools based on the
gene pool classification system proposed by Harlan
and de Wet (1971). The primary gene pool includes
all cultivated and hexaploids wild species, which
directly cross with cultivated oat easily. The secondary
gene pool contains some tetraploid species (A. magna,
A. murphyi, A. insularis, etc.), which cross with
cultivated oat directly, though they produce sterile
progeny. Hybrids of A. sativa with these species are
partially, and increasing with backcrossing, female
fertile, and natural recombination occurs best with
A. insularis. The secondary gene pool contains several
desirable traits and needs to be better explored in
respect to collection as well as evaluation. The tertiary
gene pool includes diploid and the remaining tetraploid species requiring application of in vitro techniques for hybridization (Jellen and Leggett 2006).
Nevertheless, it is considered a rich reservoir of diversity for oat breeding.
In their turn, the crosses between cultivated and
wild oats can be subdivided into two groups (1) the
ones that proceed easily and gave either fertile (with
3 Avena
all hexaploid species) or partially sterile (with AC
genome species A. magna and A. murphyi) progeny,
and (2) the crosses that proceed with difficulty and
gave a progeny that is either sterile to a considerable
degree (e.g., with A. barbata) or completely sterile,
as is the case with A. prostrata and A. vaviloviana
(Leggett 1996).
The difficulty of transferring alleles from diploid
and tetraploid species into hexaploid forms had been
noticed by many authors (Leggett 1996; Mitrofanov
and Mitrofanova 1972), and its essence is in crossing
the crossability barrier. This problem can be solved by
using mutants, genetic transformation, or by applying
the method of backcrosses. Chromosome duplication
induced by colchicine treatment is often used to overcome sterility of the hybrids between diploid species
and the hexaploid cultivated oats. Irradiation with
thermal neutrons made it possible to cross the tetraploid species A. abyssinica with A. sativa (Sharma and
Forsberg 1977). The possibility of transferring entire
chromosomes or their parts from diploid species to the
cultivated hexaploid oat genome using genetic carriers
has been confirmed by successful hybridization of
many species. The most promising among the method
for overcoming the inability of chromosomes to conjugate employs the CW-57 accession of diploid
A. longiglumis, which facilitated the homeologous
chromosome conjugation at the transfer of traits from
tetraploid A. barbata to hexaploid A. sativa (Thomas
1988). The reason is that the diploid species contains the “wild” diploidization suppressor allele and
the gene responsible for the genome recombination
(Rajhathy 1966). A good example of using such a
vector is the creation of the hexaploids Amagalon
line by crossing A. sativa with A. magna via A. longiglumis. The same procedure may be used for crossing
other species, too. Fertility of the pentaploid sterile
hybrids, which can be obtained through simple crosses
between tetraploid A. magna, A. murphyi, and hexaploid A. sativa, can later be completely restored
through backcrossing these hybrids with the cultivated
oat. This scheme of using tetraploid species in breeding oat for grain quality and large grain size was
developed in Sweden (Hagberg 1983). The procedure
of natural backcrossing by growing pentaploid F1
hybrids on the plots of cultivated oat can also be
applied when A. barbata and A. macrostaсhya are
used in crossings.
For the first time, wild hexaploid oat species were
experimentally used in breeding for an increased grain
yield in 1936. The species A. fatua had been recommended for the purpose. It was proved that the main
traits of cultivated oat dominated in the progeny from
interspecific hybrids (Emme 1938; Vavilov 1962).
A study of interspecific hybrids did not confirm the
opinion that the hybrid resulting from a cross with
hexaploid A. sterilis is difficult to get rid of a set of
such “wild” traits as the presence of callus increased
huskness of grains, wild type of awnedness, etc.
(Popovic 1960). The use of the species in cultivated
oat breeding has been found to significantly increase
biomass and vigor in hybrid plants. These traits were
discovered to be controlled by additive alleles.
For the first time, wild oat species were used for
practical breeding purposes in the 20s of the twentieth century. However, the earliest commercial varieties created with their use appeared only in the
1960s. In the former USSR, A. fatua had been used
by breeders in their work for development of winter
type of oat varieties (Loskutov 2007). In Great Britain, diploid and tetraploid wild oat species have been
successfully used as sources of resistance to the most
important oat disease, which is mildew. The trait of
resistance had been transferred from A. barbata into a
series of oat cultivars, namely Maris Tabard, Maris
Oberon, Margam, and Maldwyn (Jones et al. 1984).
A. fatua had been used for creating the winter oat
Mostyn that carries genes for mildew resistance
(Hayes 1970). Beginning in the 1960s, oat breeding
in the US has widely employed the use of wild hexaploids species (Frey 1991, 1994), particularly for
disease resistance. The species A. fatua and A. sterilis
have served as major contributors in creating many
oat cultivars, which have occupied or now occupy
considerable areas in the US, Canada, Brazil, and
Australia.
Therefore, the availability of well-developed breeding methods and numerous successful practical results
confirm the possibility of effective transfer of many
agronomically important traits into cultivated oat by
means of interspecific hybridization for raising hereditary potential and broadening genetic basis of the
entire genus.
Genetically, oat is insufficiently studied in comparison with other cereal crops. The trait-oriented
genetic collections composed in different laboratories
AU17
I.G. Loskutov and H.W. Rines
in Europe and America are small (Dielz 1928;
Litzenberger 1949; Fleischmann et al. 1971b; Simons
et al. 1978; Marshall and Shaner 1992; Nielsen 1993),
though the first genetic research on the inheritance of
morphological traits in oats, e.g., color and pubescence of glumes (Surface 1916), has been carried
out since the beginning of the twentieth century.
Significant attention in genetic studies have been
paid to morphological traits of generative organs,
which were studied most thoroughly in relation to
the problems with systematics and phylogeny of the
genus Avena. Later on, the genes governing resistance
and susceptibility to diseases and pests have been
identified and genetic control of polymorphic protein
systems and generative organs development has been
established, thus making these data very useful for
breeding purposes. In 1978, a list of genes was published (Simons et al. 1978) and extended in 1992
(Marshall and Shaner 1992). Over 300 genes controlling different traits have been identified in oats,
and only single alleles responsible for morphological
traits were localized in concrete chromosomes.
Later on, composition of the genetic collection
kept growing continuously, mainly following new
publications, primarily in “Crop Science” and “Oat
Newsletter.” In 1997, VIR published a Catalog with
descriptions of accessions in the genetic oat collection
(Loskutov 2007), which included cultivars, cultivated
lines, and wild accessions with one or more identified
genes controlling different morphological, agrobiological, biochemical, and other traits. A big part of the
collection is represented by accessions with the most
important genes of resistance to mildew, crown and
stem rusts, and smut species. At present, the genetic
collection of oats at VIR includes over 600 accessions
belonging to both cultivated (A. sativa, A. byzantina,
A. strigosa, A. abyssinica) and wild (A. sterilis,
A. barbata, A. magna) species that contain over 200
identified genes controlling different morphological,
physiological, biochemical, and other traits.
The use of donors with the identified genes that
ensure clear manifestation of a trait makes it possible
to predict the results of investigations with sufficient
precision, it being quite important when carrying out
breeding for quality, plant height, and other traits. The
role of donors is especially important in broadening
the genetic basis of cultivated oats concerning resistance to smut and rust species as well as other diseases.
The use of the genetic collection increases efficiency
of the breeding work, facilitates selection of parental
pairs for crosses, and accelerates creation of cultivars
with required parameters.
All information about the accessions with identified
genes from the oat genetic collection is available in
the European Avena Database (EADB) established on
the initiative of ECPGR and Avena Working Group
at FAL (now part of the Julius K€uhn-Institute, JKI,
Germany) (http://eadb.bafz.de/CCDB_PHP/eadb/).
3.5 Role in Crop Improvement Through
Traditional and Advanced Tools
3.5.1 Potential of Wild Oat Germplasm
for Oat Improvement
The main objectives of agricultural crop breeding are
to increase their productivity and improve grain quality characters. Raising plant productivity requires
breeding cultivars with high productivity and quality
potential as well as resistance to biotic and abiotic
stresses. Resistance of wild oat species to unfavorable
environmental factors, pathogenic organisms, their
wide adaptability to different soil and climatic conditions, and a number of traits determining high productivity and quality are of special interest in the context
of oat breeding.
3.5.1.1 Vegetative Period
Oat displays great interspecific diversity in terms of
duration of vegetative period. In oat breeding, duration
of vegetative period is a very important character,
which is directly related to grain yield, its quality,
and seed sowing properties.
Wild forms may contain populations with very different duration of the vegetative period (Trofimovskaya
et al. 1976). In terms of duration of vegetative period,
Malzev (1930) subdivides all oat species into spring,
intermediate, and winter forms. The spring forms produce fertile stems within one summer; the intermediate forms produce turf similar to the winter ones and
generate shoots during the first year of vegetation,
while the winter forms do not produce fertile stems
during this period. The late or winter phenotype is
3 Avena
more characteristic of the diploid and tetraploid species. For A. sterilis, all three vegetative period phenotypes – from the winter to spring ones – are
characteristic, while for A. ludoviciana, the winter one
is more typical, and for A. fatua, the spring, early
type of development is more characteristic. The northern forms of this species have been found to have a
shortened vegetative period, while it is longer for the
southern ones.
The wild species are traditionally believed to have
an extended vegetative period and its individual
stages, but the performed investigations have yielded
a wide range of early forms, the use of which in
breeding for earliness may be quite promising. Some
accessions of such species as A. canariensis, A. abyssinica, A. fatua, and A. sterilis have a shorter vegetative period, if compared to the cultivated forms, and
can be both potentially and practically used in breeding programs (Trofimovskaya et al. 1976; Mal 1987;
Frey 1991). A study of the BC2 breeding lines involving A. fatua has found them to burst out 3 days earlier
than the parental forms (Stevens and Brinkman 1986).
Another hexaploids species, A. sterilis, is believed by
many authors to be an inexhaustible source of alleles
determining a wide range of seed maturation dates
(Welsh 1945; Hayes 1970; Hagberg 1983). Notable
is that special earliness was characteristic of accessions of the species collected in Ethiopia (Rezai 1978).
A big set of accessions of wild species has been
analyzed from the point of view of the duration of
vegetative period, and a considerable degree of variation in duration of separate stages of development
was revealed by forms of A. clauda, A. pilosa, A.
longiglumis, A. wiestii, A. hirtula, A. barbata, A. agadiriana, A. ludoviciana, and A. sterilis. Thus, early
spring forms as well as late intermediate and semiwinter forms of oat have been found among these
species (Loskutov 2007).
The study has shown that the shortest individual
stages of development and the entire vegetative period
among diploid and tetraploid species were characteristic of A. prostrata, A. canariensis, A. atlantica,
A. vaviloviana, and A. magna, while the longest – of
A. bruhnsiana, A. ventricosa, and A. agadiriana. It
should be noted that the difference between the lowest
and highest average values amounted to over 20 days.
Among hexaploid species, A. fatua showed the shortest individual stages of development and the entire
vegetative period, while A. sterilis, A. ludoviciana,
and A. occidentalis had the longest ones. The average
value difference between these species was only 10
days (Loskutov 1998, 2007).
Therefore, the analysis of correlations between
duration of different phases and the entire vegetative
period shows a higher probability of discovering
more early or spring forms in the northwest of the
Mediterranean center of origin of cultivated plants,
that is, in southwestern Europe and northwestern
Africa and its archipelago, while intermediate spring
and semi-winter forms are more likely to be found in
the west of the Asian continent. Besides, the localities
where the endemic Ethiopian species A. vaviloviana
had been collected suppose the origin of the most early
forms presumably from the regions located southeast
of Addis Ababa and from the southern coastal regions
of Ethiopia (Loskutov 2007).
To sum it up, investigations of the cultivated forms
of oat have been accompanied by the analysis of data
from studies of wild oat species with different ploidy
levels, which has shown the presence of early spring
forms possessing either individual shortened stages of
plant development or a shorter vegetative period.
These forms can be used in breeding early cultivars.
3.5.1.2 Response to Photoperiod
and Vernalization
The most important factors determining a plant’s vegetative period duration, especially before heading, are
the day-length and temperature regime. Not only winter crops need vernalization at the early stage of development but also almost all oat species require it to a
small degree. The influence of day-length and low
temperatures on the initial stages of oat species
development had been noted by many researchers
(Qualset and Peterson 1978; Thomas and Naqvi
1991; Rodionova et al. 1994). A study of A. byzantina
has singled out a unique, photoperiod-insensitive
Turkish oat landrace, which was later on quite widely
used worldwide in breeding oat for photoperiodic sensitivity (Sampson and Burrows 1972). Besides, weak
response to photoperiod has been described for some
A. abyssinica accessions (Razumov 1961; Arias and
Frey 1973; Loskutov 2001a).
Some forms of wild species have been shown to
be insensitive to photoperiod and vernalization. The
reason is that the center origin and diversity of wild
I.G. Loskutov and H.W. Rines
oat species are located in the Mediterranean region,
countries on the Black and Caspian seas, and in
Central Asian countries. The widest diversity is found
between 30 and 40 N (Vavilov 1965a, 1992; Baum
1977). Initial stages of development of many wild oat
species fall on cold months; besides, they grow at high
altitudes (up to 2,000 m), hence are peculiarities of
their response to the environmental factors including
photoperiod and temperature (Paterson et al. 1976;
Darmency and Aujas 1986).
Screening of a large set of wild species has identified truly winter genotypes within A. clauda, A. barbata, A. ludoviciana, and A. sterilis, and truly spring
forms within A. wiestii, A. canariensis, and A. magna.
A. vaviloviana and A. fatua may be regarded as truly
spring species because of their neutral or weak
response to vernalization. Besides, forms of A. fatua
have displayed a strong response to day-length
(Loskutov 2007). The typically spring type of development of these species indicates their secondary origin compared to those characterized by winter and
semi-winter forms, it being confirmed in literature
(Jellen and Beard 2000). Apparently, the availability
of spring forms and a strong day-length sensitivity
allow the forms of A. fatua to spread to the northernmost territories and climb up high into the mountains
to the altitudinal limits of high mountain agriculture
(Loskutov 2007).
Forms of A. hirtula, A. vaviloviana, and A. occidentalis displayed weak response to photoperiod,
while forms of A. clauda, A. murphyi, and A. sterilis
showed a very strong response to day-length variation
(Loskutov 2001a). A perennial autotetraploid species A. macrostachya displayed a strong photoperiodic
response under vernalization, while forms of A. magna
were strong day-length sensitive (Sampson and
Burrows 1972; Loskutov 2007).
Response to vernalization has been shown to
depend on geographic origin of particular accessions,
while response to photoperiod variation has been
found to be predominantly species-dependent. There
exists no direct relation between geographic origin of a
species and photoperiodic response. At the same time,
several accessions with a very weak or neutral photoperiodic sensitivity originated from the regions either
adjacent to, or located south of 40 N, that is, from the
Canaries (Spain), Corsica (France), Crete (Greece),
Azerbaijan, Turkey, Morocco, Tunisia, Lebanon, and
Ethiopia (Loskutov 2001a, 2007).
3.5.1.3 Plant Height and Lodging Resistance
Variation in plant height is quite high among species
of the Avena genus. This helps to select and create new
initial material combining optimal plant height with
other agronomically important traits. Wild oat species
with different ploidy levels have been studied with the
aim of broadening the genetic basis of such traits as
semi-dwarfness and lodging resistance. The use of a
fairly short-stem diploid species A. pilosa in stepwise
hybridization has been found to reduce plant height in
cultivated oat (Hoppe and Hoppe 1991). According to
many authors, hexaploid species A. fatua and A. sterilis are the sources of new alleles of genes determining
wide variation in plant height (Welsh 1945; Hayes
1970; Frey 1991).
A study has shown that among diploid and tetraploid species, the lowest plant height was characteristic of endemic species from Spain (A. prostrata), the
Canaries (A. canariensis), and from Morocco (A. agadiriana). Some semi-dwarfness forms of other species
have been found in Azerbaijan (A. pilosa), Cyprus
(A. ventricosa), Iran (A. clauda), Syria (A. pilosa),
Morocco (A. damascena, A. magna), and Algeria (A.
hirtula). Plants of A. fatua and A. ludoviciana with an
average height of up to 65 cm have been found in
Turkey, Iran, Iraq, Israel, Morocco, Ethiopia, and
Kenya. The overwhelming majority of semi-dwarf
accessions belong to A. sterilis. Itsgrows to an average height of up to 50 cm and it originated from
Turkey, Iran, Iraq, Syria, Israel, Morocco, Tunisia,
and Lebanon (Loskutov 2007).
The problem of plant height is closely related to oat
lodging; it occupies a special place in oat breeding and
attracts significant attention because of the plant habit
peculiarities. Due to morphological characters, (juvenile growth prostrate to semi-prostrate, flowering thin
stems geniculate and high “windage” of the panicle),
the majority of wild species are sensitive to lodging.
However, some forms of the hexaploid A. occidentalis
have been found to have an erect juvenile growth and
thicker stem walls, the structure of which resembled
that of A. magna. These characters may be used for
improving lodging resistance in cultivated oat (Baum
1971). A study of a diploid species A. wiestii has
shown that its forms possess a wide range of adaptive
responses of the root system related to lodging resistance (Holden 1969). At the same time, a study of root
volume and growth rate in A. sterilis has identified an
3 Avena
accession from Sicily with quantitative characters
(volume of the root system, root dry weight, panicles,
and straw dry weight) 2–3 times higher than those in
other forms of wild and cultivated oats (Carrigan and
Frey 1980). Among the diversity of wild hexaploid
species of plant height and lodging resistance, the
most interesting semi-dwarf and lodging resistant
forms have been found among A. fatua, A. ludoviciana, and A. sterilis (Loskutov 2007).
To sum it up, selection of new sources of shorter
plant height and lodging resistance among both
cultivated and wild species allows the breeders to
enjoy a higher degree of flexibility in their work and
thus reduce the risk of genetic erosion of genotypes
at the intraspecific level.
3.5.1.4 Agronomical Important Characters
The main trend in breeding is the raising of a cultivar’s grain productivity. In the first place, this character and quality of oat cultivars depend on the
panicle size, number of grains in the panicle, size,
and presence/absence of husk on the caryopsis. A
study of the elements of productivity in wild oat
species has shown that the highest number of spikelets in the panicle and the highest density of the latter
were characteristic of some forms of A. prostrata, A.
wiestii, A. vaviloviana, A. abyssinica, A. fatua, and
A. sterilis (Trofimovskaya et al. 1976; Thomas and
Griffiths 1985; Mal 1987; Kanan and Jaradat 1996).
High values of the same characters were demonstrated by accessions of A. hirtula and A. wiestii
collected in Italy (Sicily and Sardinia), Azerbaijan,
Iran, Israel, and Egypt, of A. barbata from Azerbaijan,
Israel, and Lebanon, of A. vaviloviana collected in
Ethiopia, and of A. fatua collected in Georgia,
Kazakhstan, Bulgaria, and China (Loskutov 2007).
Some accessions of A. sterilis from Central Asia and
the Middle East were also noted for these characters
(Rezai and Frey 1988, 1990).
To a greater degree, a lower huskness correlates
positively with grain size and high grain test weight
and negatively with the degree of lodging and high
susceptibility to rust diseases. Sources possessing
these characters may be found among wild species,
too. When crossed with cultivated oat, a diploid species A. pilosa with small grain and high percentage
of huskness has reliably demonstrated an increase in
the values of the characters (Hoppe and Hoppe 1991).
The related tetraploid species A. magna, A. murphyi,
and A. insularis have been noted for large grain size
(1,000-grain weight reached 35 g) (Martens et al.
1980; Ladizinsky 1988, 1998; Loskutov 2007).
A. sterilis is a rich source of alleles of genes governing variation of grain size in a wide range (Welsh
1945; Hayes 1970). The largest grain size and the
highest 1,000-grain weight have been recorded for
the accessions collected in Southwestern Europe
and Northern Africa (Rezai and Frey 1989b, 1990).
At the same time, some African forms of A. sterilis had
impressive spikelets, which were 2.5-times larger than
those of other species (Vavilov 1965a, 1992). Hybrid
lines obtained by crossing A. fatua with cultivated oat
had larger grain than the parental forms (Stevens and
Brinkman 1986).
The largest grain size has been found among the
forms of A. fatua from Russia, Tajikistan, Poland, and
Mongolia, of A. ludoviciana from Azerbaijan, Georgia,
Turkey, and Iran, and of A. sterilis from Turkey, Iran,
Iraq, Israel, Tunisia, and Morocco. The correlation
analysis has shown the most large-grained forms of
hexaploid species to be associated with southwestern
Europe and northwestern Africa (Loskutov 1998). It
should be noted that the most interesting forms with
the weakest huskness and the largest 1,000-grain
weight were the forms of A. fatua from Russia, Poland,
and Mongolia, of A. ludoviciana from Azerbaijan and
Iran, as well as of A. sterilis from Turkey and Tunisia
(Loskutov 2007).
Another character related to yielding ability is the
productive tillering. A higher degree of productive
tillering has been found to be characteristic of some
forms of wild diploids A. prostrata, A. damascena,
A. wiestii, and A. hirtula (Mal 1987; Kanan and
Jaradat 1996) and tetraploids A. murphyi and A. magna
(Ladizinsky 1988). When transferring this character
from tetraploid species to a hexaploid cultivated
species, two backcrosses are sufficient for obtaining
stable hexaploid genotypes (Zadoo et al. 1988).
The best forms of A. fatua are regarded by many
authors as the best partners in breeding for higher
yields and grain quality (Yamaguchi 1977). This species is promising for creating cultivars with different
duration of seed dormancy, which permits to increase
grain yields by 13–24% (Burrows 1970). The species
transfers a higher spring sprouting ability and shattering resistance to cultivated oats (Frey 1985, 1991).
I.G. Loskutov and H.W. Rines
A consideration of yielding ability and other characteristics of interspecific hybrids involving A. sterilis
shows that alleles of genes from wild species can
increase vegetative vigor, grain yield, and straw
weight in hybrid plants (Cox and Frey 1984a, b; Frey
et al. 1984; Takeda and Frey 1985, 1987; Gupta et al.
1986a, b, 1987). To transfer these characters by means
of interspecific crosses, the method of backcrosses
is applied quite efficiently (Takeda et al. 1985; Frey
1988; Holland et al. 1996). Cytoplasm of a wild species had a significant influence on grain yield in certain
combinations (Beavis and Frey 1987), total straw
weight, plant height, and the vegetative vigor. The
findings indicated the potential of A. sterilis for creating cultivars with a more stable productivity and
less dependence on the environmental conditions
(Robertson and Frey 1984).
Thus, the study has found that wild species possess agronomically important characters, which may
be used in improving the existing cultivars through
breeding.
3.5.1.5 Resistance to Diseases and Pests
Oat diseases and pests are still the main factors
reducing yields and grain quality. The most efficient
method of protecting plants from diseases and pests
is the breeding of resistant cultivars. Their development requires different donors and sources of
resistance. The main task of breeding for disease
resistance is to restore in cultivated oats the lost
genetic diversity as regards resistance to diseases
and pests, initially possessed by wild progenitors.
Therefore, a complex phytopathological study of all
the specific diversity of Avena genus promotes identification of new sources and donors of resistance for
their use for broadening genetic basis of the created
oat cultivars (Clifford 1995).
Resistance to Diseases
Crown and stem rusts. Crown rust, caused by the
fungus P. coronata Cda. f. sp. avenae Fraser et Led.,
and stem rust, caused by the fungus P. graminis Pers.
f. sp. avenae Eriks. & Henn., are spread everywhere
and affect the majority of oat crops. Numerous investigations of wild oat species show that their majority
possesses a high degree of resistance to rusts
(Table 3.10). For example, these are the diploid species A. clauda, A. pilosa, A. longiglumis, A. damascena, A. prostrata, A. canariensis, A. wiestii, and
A. hirtula and tetraploids A. barbata, A. vaviloviana,
A. abyssinica, and A. magna possessing complex
resistance to rust species (Sebesta et al. 1987; Harder
et al. 1992; Saidi 1998).
According to Vavilov’s research (1935), the diploid
species A. clauda and A. pilosa possessed resistance to
crown rust (Vavilov 1951, 1964a). It had been established that the extreme variants of resistance to crown
and stem rusts and to loose smut and powdery mildew
are displayed by the diploid oat species (Vavilov 1951,
1964b, c). Consequent experiments with artificial
infection of A. barbata have shown the existence of
two very different groups, that is, a group strongly
susceptible to all parasites and very resistant one.
Forms of A. barbata from Persia, as well as forms of
A. vaviloviana from Ethiopia, were strongly affected
by rust species, while forms of A. sterilis happened to
be susceptible to stem rust and medium resistant to
crown rust (Vavilov 1965a, 1992). The performed
analysis made it possible to suppose that high degree
of resistance is displayed by representatives of the
groups, which had formed under the conditions favorable for the development of infection, and that resistant forms should be sought in the areas where the
parasite originated. It was further confirmed in his
later works (Vavilov 1957).
According to Mordvinkina (1969a), the Pyrenean
and Moroccan groups of A. hirtula demonstrated complex resistance to fungous diseases, while the South
Palestinian group and the forms from Corsica were
susceptible to them. Medium resistance to crown rust
was characteristic of the Mediterranean forms of
A. barbata, though South-Asian forms got affected
by this disease. In general, resistance of these species
was confirmed in consequent studies (Simons et al.
1959; Leggett 1992a). The highest degree of resistance
to crown and stem rusts was demonstrated by accessions of A. barbata collected in Israel (Dinoor
and Wahl 1963). Forms of this species collected in
Northern Australia were more resistant to stem rust
than southern population (Burdon et al. 1983, 1992).
Some forms of A. barbata possessed resistance only at
the juvenile stage of development and were losing
it during the reproductive stage (Karow et al. 1987).
It had been established that crown rust resistance could
3 Avena
Table 3.10 Sources of diseases resistance in oat species
Species
Genome
Sources of resistance to
powdery mildew
Crown rust
A. bruhnsiana
Cv
þ
þ
A. ventricosa
Cv
þ
þ
A. clauda
Cp
þ
þ
A. pilosa
Cp
þ
þ
A. prostrata
Ap
þ
þ
A. damascena
Ad
þ
þ
A. longiglumis
Al
þ
þ
A. canariensis
Ac
þ
A. wiestii
As
þ
þ
A. hirtula
As
þ
þ
A. atlantica
As
þ
A. strigiosa
As
þ
þ
A. barbata
AB
þ
þ
A. vaviloviana
AB
þ
þ
A. abyssinica
AB
þ
þ
A. agadiriana
AB?
þ
A. magna
AC
þ
A. murphyi
AC
þ
þ
A. insularis
AC?
þ
A. macrostachya
CC?
þ
þ
A. fatua
ACD
þ
þ
A. occidentalis
ACD
þ
þ
A. ludoviciana
ACD
þ
þ
A. sterilis
ACD
þ
þ
be transferred to hexaploid species by means of
amphiploid synthesis (Williams and Verma 1956).
Reciprocal crosses have yielded a hexaploid line that
contained an allele of the A. barbata gene governing
resistance to stem rust Pg16 and had a grain yield
nearly that of cultivated oat (Martens et al. 1983;
Brown 1985; Ohm and Shaner 1992).
When considering diversity of resistance to crown
rust, it was found that resistance to this pathogen was
displayed by forms of diploid species A. bruhnsiana,
A. ventricosa, A. longiglumis, A. hirtula, of tetraploid
species A. magna, A. insularis, A. murphyi, and A.
macrostachya, while resistance to stem rust was
found to be possessed by such diploids as A. pilosa,
A. longiglumis, and A. hirtula and by a tetraploid A.
macrostachya (Loskutov 2007).
A. abyssinica may be of much importance for synthetic breeding in the case of stepwise interspecific
hybridization involving 14 , 28 , and 42-chromosome oats aimed at transferring the well-expressed
resistance to fungal diseases from the group of diploid
oat species to cultivated oats (Vavilov 1965a, 1992).
Stem rust
BYDV
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
Smut ssp.
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
Septoria leaf blight
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
The species A. magna and A. murphyi have been
found to possess a higher resistance to crown rust
(Sebesta et al. 1987; Ladizinsky 1988; Leggett
1992a). High resistance to the most aggressive races
of crown rust was displayed by sprouts and adult
plants of A. magna (Murphy et al. 1968). This species
and A. longiglumis as the carrier were used to produce
the Amagalon (A. mag-na þ A. lon-giglumis) line, in
which allele of the gene has been identified with
molecular markers (Rooney et al. 1994; Wilson and
McMullen 1996b).
All investigations have found A. macrostachya, a
perennial tetraploid species, to be characterized by
resistance to both crown and stem rusts and that can
be successfully crossed to cultivated oat (Leggett
1992b; Loskutov 2007).
A study of the forms of A. fatua has found individual populations to have a higher degree of crown and
stem rust resistance (Suneson 1948; Burdon et al.
1983; Simons and Briggle 1984; Johnson and Rothman
1986; Burdon and Muller 1987; Sebesta and Kuhn
1990). The accessions of A. fatua from Central Asia
I.G. Loskutov and H.W. Rines
displayed high resistance to 200 races of rust. The
American populations of this species collected in the
North Central states of the country happened to be
susceptible to the stem rust isolates tested (Rines
et al. 1980). On the whole, this species is characterized
as having some resistance to stem and crown rusts
(Frey 1991). According to many authors, the hexaploid species A. sterilis represents a rich source of
alleles of genes controlling resistance to different
races of crown and stem rusts (Welsh 1945; Suneson
1948; Hayes 1970; Harder et al. 1980, 1984; Frey
1983, 1991, 1994; Harder and McKenzie 1984; Wahl
and Segal 1986; Leggett 1992a). It has been proved
that in crosses involving the forms of A. sterilis, resistance of the progeny is influenced not only by the
nuclear genetic material (Wilson and McMullen
1997a, b) but also by cytoplasm (Simons 1985; Simons
et al. 1985). The inclusion of this species in the list
of identifiers of physiological races of rust causal
agents made it possible to identify almost 500 races
of stem rust and 800 races of crown rust (Fleischmann
and McKenzie 1968; Fleischman and Baker 1971;
Fleischmann et al. 1971a, b). A study of several forms
of this species has found correlations between crown
rust resistance, protein content, potential grain yield,
and powdery mildew resistance (Simons 1965, 1979;
Popovic 1980). Alleles of rust resistance genes are
frequently linked with the alleles controlling morphological traits of the grains, particularly color of lemma
or its pubescence (Kiehn et al. 1976; Wong et al. 1983).
Individual accessions of A. sterilis from southwestern
Europe and countries of Asia and Africa are noted for
a high resistance to rust diseases (McKenzie and
Fleischmann 1964; McKenzie et al. 1970; Martens
and McKenzie 1973; Kim 1974; Brodny et al. 1976;
Rezai 1978; Simons 1985; Wahl and Segal 1986;
Sebesta et al. 1987; Simons et al. 1987; Harder et al.
1990). The forms of A. sterilis from Turkey, Iran, and
Iraq are resistant to crown rust and, apparently, possess an allele of the Pc54 gene or alleles of stem rust
resistance genes (Martens et al. 1980, 1981).
A. ludoviciana, related to A. sterilis, is also characterized by resistance to crown rust (Welsh 1945;
Griffiths et al. 1959; Lupton and Thompson 1961;
Clamot 1969; Hayes 1970; Sebesta et al. 1987) and
to stem rust (Leggett 1992a). The accessions collected
in northern Australia were more resistant to stem rust
than southern forms of this species (Burdon et al.
1983; Oates et al. 1983).
The accessions of A. sterilis, A. ludoviciana, and A.
occidentalis with the highest resistance to crown rust
originated from Spain, Italy, France, Turkey, Israel,
Iran, Lebanon, Algeria, Tunis and USA. Complex
resistance to the main obligate fungal parasites
(crown and stem rusts) were characteristic of the
forms of tetraploid species A. magna, A. insularis,
and A. macrostachya and hexaploid species A. occidentalis, A. ludoviciana, and A. sterilis (Loskutov
1998, 2007).
An analysis of the obtained data has shown that
the forms of wild species with a higher resistance to
crown rust were concentrated in the northwestern
regions of the African continent, while resistant
forms of A. barbata were concentrated in south of
this species’ natural range where strong epiphytotics
of crown rust are most frequent. Besides, it has been
discovered that crown rust weakens the diseased plants
and it leads to their medium infection by stem rust
(Loskutov 2007).
Powdery mildew is caused by the fungus Erysiphe
graminis D. C. f. sp. avenae Em. March., is recorded
everywhere and reveals itself on leaves, in leaf sheaths,
and on plant stems (Table 3.10).
According to Vavilov, accessions of the wild diploid species A. clauda and tetraploid A. barbata were
characterized by a higher resistance to powdery mildew (Vavilov 1965a, 1992). Later on, Mordvinkina
(1969b) determined geographic boundaries of these
groups of A. barbata: powdery mildew resistance
was characteristic of the Mediterranean forms, while
South-Asian ones were susceptible to the pathogen.
Further investigations undertaken by many authors
have confirmed the supposition that these species possess resistance to powdery mildew (Aung et al. 1977;
Aung and Thomas 1978; Thomas and Aung 1978;
Harder et al. 1992; Leggett 1992a). According to
many researchers, resistance to powdery mildew is
exhibited by many wild species, namely diploid species A. pilosa, A. ventricosa, A. longiglumis, A. prostrata, A. damascena, A. hirtula, and A. atlantica;
tetraploids A. barbata, A. vaviloviana, A. abyssinica,
A. agadiriana, A. magna, and A. murphyi, and hexaploids A. fatua, A. occidentalis, A. sterilis and A.
ludoviciana (Welsh 1945; Jones and Griffiths 1952;
Lupton and Thompson 1961; Clamot 1969; Hayes
1970; Ladizinsky 1988, 1992; Thomas 1988; Frey
1991, 1994; Harder et al. 1992; Leggett 1992a;
Zwatz et al. 1994; Herrmann and Roderick 1996).
AU18
3 Avena
The highest resistance was registered for all Azerbaijanian accessions of A. bruhnsiana, A. clauda, and
some forms of A. pilosa, A. wiestii, and A. barbata
(Loskutov 2007).
A series of works on the transfer of alleles of the
powdery mildew resistance genes from diploid species
to cultivated oats have been undertaken at the Welsh
Plant Breeding Station, University College of Wales
(UK). The accession Cc 3678 (A. hirtula) was used to
transfer powdery mildew resistance to hexaploid species via a genetic bridge of artificial amphiploids
involving A. longiglumis (CW 57) (Thomas 1968).
The accession Cc 4852 A. ventricosa, bearing an allele
of the gene for resistance to powdery mildew races 2,
3, and 5, was included in the breeding program and
crossing program (Thomas and Thomas 1970). The F4
line with a chromosome replacement from A. prostrata bearing a gene of powdery mildew resistance
was obtained through production of an amphidiploid
(A. longiglumis (CW 57) A. sativa) (A. sativa with
chromosome A. prostrata) (Thomas and Griffiths
1985). A cross of A. macrostachya and A. prostrata
has yielded a hybrid that was morphologically similar
to A. macrostachya but was resistant to powdery mildew (Hoppe and Pohler 1988; Hoppe et al. 1990).
Hexaploid species were not characterized by high
resistance to the pathogen. At the same time, it should
be noted that some resistant forms have been found
among A. sterilis, A. ludoviciana, and A. occidentalis
(Sebesta et al. 2000).
Helminthosporium leaf blotch is caused by
Drechslera avenae (Eidam.) Ito et Kuribay. (syn.
Helminthosporium avenae Eidam; Pyrenophora avenae Ito et Kuribay.) and has been recorded everywhere
(Sebesta et al. 2001).
Resistance to this disease was noted in forms of
diploid species A. bruhnsiana and A. wiestii from
Azerbaijan, A. clauda from Turkey, A. longiglumis
from Morocco and Algeria, and A. hirtula from
Spain, Italy (Sardinia), and Tunisia. Among wild tetraploid species, high resistance was exhibited by A.
macrostachya from Algeria. Resistance to Helminthosporium leaf blotch displayed by the AC-genome
species A. magna and A. murphyi was above the average. Disease appearance was minimal also in other
species, such as A. barbata from Turkmenistan,
Portugal, Italy, Turkey, Israel, and Tunisia, A. magna
from Morocco, and A. murphyi from Spain and
Morocco. Among wild hexaploid species, there can
be noted resistant forms of A. fatua from Russia,
Ukraine, Azerbaijan, Turkey, and Iran, of A. ludoviciana from Azerbaijan, Georgia, and Iran, and of A.
sterilis from Russia, Iran, Israel, Morocco, and USA.
It should be noted that all accessions of A. occidentalis
from Spain (the Canaries) had juvenile resistance and
that their majority was resistant to the disease.
An analysis of the gathered data has shown that the
forms of wild species most resistant to Helminthosporium leaf blotch had been collected in the northern
parts of natural ranges of wild oat species, which is
near 40 N (Loskutov 2007).
Septoria leaf blight is caused by the fungus Septoria avenae Frank. (syn. Leptosphaeria avenaria
Weber.). It occurs everywhere and reveals itself from
the tillering stage (Table 3.10).
Among wild species, A. wiestii and A. sterilis
apparently possess high resistance to Septoria leaf
blight under both natural and artificial inoculation
(Clark and Zillinsky 1960; Thomas 1988; Harder
et al. 1992; Zwatz et al. 1994; Sebesta et al. 1999).
Resistance to the disease was also characteristic of
accessions of such diploid species as A. atlantica from
Morocco, A. canariensis from Spain (the Canaries),
A. damascena from Morocco, and A. hirtula from Italy
(Sicily, Sardinia). Among wild tetraploid species,
perennial A. macrostachya from Algeria has been
noted for resistance to the disease in question. Moderate susceptibility has been recorded for A. vaviloviana
and A. murphyi, and resistance has been displayed by
forms of A. barbata from Azerbaijan, Portugal, and
Israel. A sufficient number of forms with resistance to
Septoria leaf blight have been found among hexaploid
species. Many forms of A. fatua have been found to be
resistant; they have geographically diverse origins:
Russia, Ukraine, Georgia, Azerbaijan, Armenia,
Kazakhstan, Tajikistan, Poland, Bulgaria, Czechoslovakia,
Iraq, Turkey, Mongolia, and Argentina. The forms of
A. ludoviciana from Czechia, Morocco, and USA have
been found to be resistant to Septoria leaf blight. Among
A. sterilis accessions, resistant forms originated from
Turkey, Iran, Syria, Israel, Algeria, Morocco, Tunisia,
Lebanon, and Ethiopia (Loskutov 2007).
Myrothecium necrotic blight is caused by the fungus Myrothecium verrucaria Ditmar. ex Fran. and
manifests itself in the beginning of vegetation, most
often at the tillering stage or during the leaf-tube
formation. Resistance to this pathogen has been displayed by accessions of diploid species from different
AU19
I.G. Loskutov and H.W. Rines
regions of Azerbaijan, such as A. bruhnsiana, A.
pilosa, and A. wiestii, by forms of A. hirtula from
Italy, Spain, Israel, and Tunisia, as well as by forms
of tetraploid A. murphyi from Spain and Morocco, A.
agadiriana from Morocco, A. barbata from Iran and
Israel, and A. macrostachya from Algeria. The majority of hexaploid forms of A. fatua possessing resistance to Myrothecium necrotic blight originate from
Russia, Armenia, Azerbaijan, Mongolia, and Ethiopia;
those of A. ludoviciana have Russian, Ukrainian,
Azerbaijanian, Georgian, Turkish, and Algerian origin
and those of A. sterilis originate from Russia, Turkey,
Iran, Syria, Israel, Algeria, Morocco, Tunisia, and US
(Loskutov 2007).
Smuts (caused by the fungi Ustilago avenae Jens.
and Ustilago kolleri Wille.) occur everywhere and do
much damage to oat crops. A study of complex resistance in oat species has shown that A. wiestii is not
resistant to loose smut (Table 3.10). Experiments on
artificial inoculation of A. strigosa and A. barbata with
smut have identified two very contrasting groups
within these species: that is, a group with strong susceptibility to all parasites, and another group with high
resistance. The strongly susceptible forms of A. barbata happened to be typical of Persia. Among them,
in some accessions, smut infection was localized to
anthers only, while in most forms, it affected all
organs of the inflorescence (Vavilov 1965a, 1992).
According to Mordvinkina (1969a), moderate resistance to smut was characteristic of the Mediterranean
forms of A. barbata, while the South-Asian forms
were affected to a greater degree. According to Vavilov, the cultivated species A. abyssinica, its wild analog A. vaviloviana, and A. sterilis were quite
susceptible to loose smut under conditions of Russia
(Vavilov 1964c, 1965a, 1992).
Further studies on resistance to loose and covered
smut have shown that almost all previously studied
species had forms that were resistant to this disease
and could be used as donor sources in breeding for this
character. The species A. strigosa, A. wiestii, A. barbata, A. vaviloviana, A. fatua, and A. sterilis (Forsberg
and Shands 1989; Frey 1991; Harder et al. 1992;
Leggett 1992a; Rodionova et al. 1994) as well as the
majority of A. abyssinica accessions (Nielsen 1978,
1993) are regarded as resistant. A study of a large set
of oat accessions has established that the majority of
most resistant forms of A. sterilis originated from
Ethiopia, Israel, Lebanon, Syria, and all North-African
countries, but some of them were found in Iran and
Iraq (Nielsen 1978).
Fusarium is caused by fungi of the Fusarium genus.
They are distributed everywhere and affect oats in the
second half of the vegetation period. It is noted in
numerous works that A. sterilis and A. ludoviciana
represent a diverse source of resistance to Fusarium
agents (Welsh 1945; Hayes 1970; Frey 1991; Gavrilova
et al. 2008).
Halo blight is caused by Pseudomonas coronofaciens Starr. and affects oat plants after the stage of
tillering and leaf-tube formation. A. vaviloviana is
resistant to halo blight and is of importance in breeding for increased productivity (Trofimovskaya et al.
1976).
Barley yellow dwarf virus (BYDV) has recently
become the most harmful disease of oat. It is caused
by Hordeum virus nanescens Rademacer et Schwarz.
When searching for new sources of resistance, a
wide range of species has been studied and a number of BYDV-tolerant forms identified (Table 3.10).
All these forms belong to the species A. longiglumis,
A. strigosa, A. barbata, A. magna, A. murphyi, A.
macrostachya, A. fatua, A. occidentalis, and A. sterilis (Frey 1983, 1991, 1994; Comeau 1988; Forsberg
and Shands 1989; Harder et al. 1992; Leggett 1992a;
Saidi 1998).
A study of a representative set of accessions has
found moderate tolerance in variants of the A-genome
diploid species A. canariensis (Ac) and A. wiestii
(As), while the most susceptible happened to be variants of the C-genome oat species A. bruhnsiana (Cv),
A. ventricosa (Cv), A. clauda (Cp), and A. pilosa (Cp).
Individual accessions had moderate tolerance, e.g.,
A. canariensis from Spain (the Canaries), A. clauda
from Greece (Crete Island), A. damascena from
Morocco, and A. hirtula from Algeria. Among the
wild tetraploids, the overwhelming number of species
displayed moderate tolerance to BYDV. The highest
tolerance was exhibited by the forms of A. barbata
from Azerbaijan and Israel, of A. vaviloviana from
Ethiopia, of A. magna from Morocco, and of A. macrostachya from Algeria (Soldatov et al. 1990).
The natural American populations of A. fatua collected predominantly in the Red River Valley in
the Northeastern states of the US were found to
have a higher BYDV tolerance (Rines et al. 1980).
A. Comeau (1984) noted high tolerance in A. occidentalis and stressed the necessity of further collecting
3 Avena
populations of this species, which are insufficiently
represented in genebanks around the world, though
these forms cross with cultivated oat easily. According
to some authors, A. sterilis represents a source of
alleles of genes governing resistance to different
viral diseases, and therefore it should be used for
breeding purposes to a greater degree (Welsh 1945;
Hayes 1970). The majority of the most tolerant forms
of this species were found in Greece, Algeria, Tunisia,
Morocco, Lebanon, Ethiopia, Kenya, western Iran,
and in the Mediterranean Turkey. Some tolerant accessions originated from Iraq, Libya, Israel, eastern
Iran, and Anatolia (Turkey) (Comeau 1984; Landry
et al. 1984).
Accessions belonging to the group of hexaploid
species were moderately tolerant to BYDV, depending
on the species. The highest percentage (31%) of tolerant accessions was found within A. occidentalis, an
endemic from the Canaries (Spain). The highest tolerance was characteristic of the A. fatua forms from
Russia, Ukraine, Georgia, Tajikistan, Poland, and
Mongolia, the forms of A. ludoviciana from Azerbaijan,
Bulgaria, Afghanistan, Israel, Morocco, and of the
A. sterilis forms from Turkey, Japan, Israel, and
Morocco (Loskutov 2007).
A comparison of the data on BYDV tolerance with
those on the abundance of aphid population has identified the accessions with true resistance to BYDV,
which belonged to the diploid species A. clauda,
A. pilosa, A. canariensis, A. hirtula, and the tetraploid
species A. barbata. Such forms have not been found
within hexaploid species, as all of them got weakly
populated with aphids. An analysis of the obtained
data has shown that the forms of wild species with a
higher BYDV tolerance had been collected from the
regions located in the western parts of the natural
ranges of wild oat species (Loskutov 2007).
Resistance to Pests
Pests cause serious damage, for instance, crop thinning, reduction of the productive tillers per plant, total
or partial seed set failure, and lower grain and sowing
material quality.
Cereal cyst nematode and stem nematode (Heterodera avenae Woll. and Ditylenchus dispaci Filip.,
respectively) affect plants at different stages of their
development and occur in many regions of oat
cultivation. Cereal cyst nematode resistance has been
found in the forms of the following wild species:
A. canariensis, A. wiestii. A. strigosa, A. barbata,
A. vaviloviana, A. abyssinica, A. magna, and A. murphyi (Harder et al. 1992; Leggett 1992a). In Australia,
the forms possessing resistance to stem nematode
have been selected from local populations of A. fatua
(Scurrah et al. 1992). Other hexaploid species A. fatua,
A. sterilis, and A. ludoviciana displayed resistance to
different nematode species (Lupton and Thompson
1961; Hayes 1970; Cotten and Hayes 1972; Hagberg
and Mattsson 1986; Jain and Hasan 1988; Frey 1991;
Leggett 1992a).
Fruit fly (Oscinella frit L.) is an internal stem feeder
causing substantial damage to oat crops. Among wild
species, A. pilosa and A. fatua were tolerant to fruit fly
(Rodionova et al. 1994).
It should be noted that some accessions of diploid
species possessed moderate tolerance to the pest.
These forms originated mainly from the African continent and from Azerbaijan, e.g., A. canariensis from
Spain (the Canaries), A. hirtula from Tunisia, A. longiglumis from Morocco, and A. wiestii from Azerbaijan
and Algeria. The level of resistance was, in general,
higher among tetraploid species than among the
diploids. High resistance to fruit fly has been recorded
for the forms of A. macrostachya from Algeria,
A. barbata from Azerbaijan, Italy, Greece, France,
Iran, and Turkey, and A. vaviloviana from Ethiopia.
Among the hexaploids, resistant forms have been
found within A. fatua from Russia, Ukraine, Georgia,
Azerbaijan, Tajikistan and Poland, A. ludoviciana
from Azerbaijan, and A. sterilis from Georgia, France,
Italy, Greece, and Morocco. An analysis of the
obtained data has shown that the forms with a higher
degree of resistance originated from the regions
located in the western parts of the natural ranges of
wild oat species (Loskutov 2007).
The bird-cherry oat aphid (Rhopalosiphum padi L.)
does significant damage to oat crops by itself and as
the BYDV transmitter. A study of a broad range of
species has identified aphid-resistant forms of such
diploid species as A. clauda from Greece (Crete
Island) and Algeria, A. pilosa from Azerbaijan,
A. ventricosa from Algeria, A. longiglumis from Israel
and Morocco, A. prostrata from Spain, and A. wiestii
from Israel and Iran (Loskutov 2007).
Resistance to different aphid species has been
found in the tetraploid species A. barbata (Weibull
I.G. Loskutov and H.W. Rines
1986; Weibull and Hanson 1986). According to the
literature, the perennial outcrossing tetraploid species
A. macrostachya is characterized by very high resistance to the aphid (Leggett 1992a). Probably, resistance of this species to aphids may be explained by
larger number of cuticle cells in leaves and an
increased content of the glutamic acid and decrease
in the aspartic acid in the cell sap (Weibull 1988b); it
is the reason why larvae develop poorly and excrete
less fluid (Weibull 1988a).
Two related AC-genome species from Morocco,
A. magna and A. murphyi, may be regarded as resistant. The AB-genome species A. agadiriana, A. vaviloviana, and A. barbata were moderately resistant,
though the last species was not quite uniform in this
respect as the former two. Degrees of resistance within
A. barbata strictly depended on the geographic origin:
high resistance was displayed by accessions from
Russia, Portugal, Spain (the Canaries), Italy, Turkey,
Morocco, and Tunisia. All hexaploid species were
resistant to the pest: resistant forms within A. fatua
were found to originate from Russia, Kazakhstan,
France, Albania, Greece, Germany, Slovakia, Poland,
Turkey, Iran, Canada, Mexico, and Argentina; all
resistant accessions of A. occidentalis originated
from the Canaries (Spain); those of A. ludoviciana
from Tunisia, Ethiopia, and the US; and resistant
forms of A. sterilis originated from Spain, Greece,
Turkey, Iraq, Iran, Syria, Israel, Algeria, Morocco,
Lebanon, Tunisia, Ethiopia, Kenya, and the US
(Loskutov 2007).
Cereal leaf beetle (Oulema melanopus L.) causes
damage to a plant at different stages of its development and is regarded as one of the most harmful
insects affecting cereals. It has been established that
leaf pubescence is a trait characterizing resistance to
this pest. A study of resistance in American populations of A. fatua has identified some forms from
Wyoming and Idaho with a medium resistance to the
phytophage (Rines et al. 1980). Resistance of some
forms of A. sterilis to the insect is connected with a
higher leaf pubescence and with the differences in
composition of the cell sap in the sprouts (Steidl
et al. 1979).
It follows from the above that one of the most
important means of creating resistant cultivated genotypes is the interspecific hybridization, which may
lead to the introgression of genes into oat cultivars.
Such crosses involving wild diploid and tetraploid
sources of resistance are possible with the use of
genetic carriers, while hexaploid species can directly
transfer a trait.
3.5.1.6 Resistance to Abiotic Factors
Oat possesses quite a range of physiological traits,
which help this crop grow in diverse conditions. The
main regions of origin and diversity of the whole
genus are predominantly located in the arid zones
with insufficient moisture and different degrees of
soil salinity and acidity and sometimes with low temperatures in the high mountain regions; therefore,
drought and cold resistance, aluminum and salt tolerance, and related traits are characteristic of many oat
species.
The search for new sources of edaphic resistance
among wild relatives of cultivated cereals has acquired
special importance, since in most cases, many characters initially possessed by wild ancestors have been
lost by cultivated species in the course of evolution.
Wild species A. wiestii, A. ludoviciana, and A. sterilis
have been found to contain highly xeromorphic forms
with hardiness to such unfavorable environmental factors as drought, heat, sharp temperature fluctuations,
and certain salt tolerance (Holden 1969; Udovenko
1977; Hagberg 1983).
Investigations have shown that the C-genome species (diploid and tetraploid) have a low level of resistance to excessive aluminum and hydrogen ions in the
nutrient medium, while the A-genome species with
different ploidy levels more often displayed high tolerance to aluminum, and the correlation analysis has
proved it. The largest group of tolerant forms belonged
to the hexaploid species A. sterilis, A. fatua, A. ludoviciana, and A. occidentalis. All wild oat species have
been found to be sources of salt-tolerance regardless of
their ploidy level. The most tolerant were the forms of
A. fatua from Georgia and Kazakhstan and of A. ludoviciana from Azerbaijan (Loskutov 2007).
Another set of characters is related to the edaphic
stress-related oat adaptation to low and negative temperatures. Such abiotic characters as cold-resistance
and winter-hardiness are very important for the wintering forms of cultivated oats. These properties are
most characteristic of the majority of wild species
3 Avena
because of their predominantly winter- or semi-winter
type of development. A tetraploid perennial outcrossing species A. macrostachya is characterized
among other oat species by an increased winter hardiness, which may be transferred to cultivated species
(Leggett 1992a; Loskutov 2007). Almost all forms of
hexaploid weedy species are cold-tolerant and winterhardy. A study of A. fatua and A. ludoviciana in the
field and laboratory conditions has confirmed them to
be cold-resistant (Pier 1964; Frey 1991; Leggett
1992a). Hybrids involving this species were cold resistant at the sprouting stage (Aujas and Darmency 1983,
1984). Cold resistance has been recorded for accessions of A. sterilis from Greece, Israel, and Turkey
(Ephrat 1962; Hetzler and Dambroth 1990). An analysis of F1 hybrids has found cold resistance to be
controlled by recessive genes with additive effect;
transgression has been observed in F2; therefore, A.
sterilis may serve as a source of alleles of the cold
resistance genes (Rajhathy et al. 1966). According to
Malzev (1930), another species A. ludoviciana truly
belongs to the winter plants, especially its forms
from Ukraine (the Crimea peninsula). This species
has been included in the program for development of
winter oat cultivars in Great Britain (Thomas and
Thomas 1970).
To sum it up, the range of acid and salt tolerance
displayed by wild oat species regardless of their ploidy
level is quite wide. All the selected accessions can
serve as sources of resistance to the considered abiotic
factors, hexaploid forms being able to directly transfer
these characters when crossed with cultivated oats.
3.5.1.7 Grain Quality Traits
Along with agronomic characters, cultivated oat has
good grain quality and green matter traits. At the same
time, it is believed that the percentage of quality components in the oat caryopsis can be augmented to a
very high level through breeding.
Protein. Percentage of protein in oat and its yield
unit quite often exceed these traits in other cereals,
and the amino acid composition in oat is balanced
better indicating good nutrient properties of the crop
(Table 3.11).
In addition to cultivated species, wild diploids
A. pilosa, A. clauda, A. ventricosa, A. longiglumis,
A. canariensis, A. damascena, A. hirtula, A. atlantica,
and A. strigosa are noted for a high (at a 20% level)
protein content in grain (Hoppe and Hoppe 1991;
Harder et al. 1992; Leggett 1992a; Miller et al. 1993;
Welch et al. 2000; Loskutov 2007). Among the accessions with the highest indices (above 20%), there
should be a mention of the forms of A. atlantica
(Morocco), A. longiglumis (Morocco), and A. wiestii
(Azerbaijan) (Loskutov 2007). Among tetraploid species, a higher content of protein in grain (above 20%)
has been demonstrated by the species A. barbata and
A. agadiriana (Trofimovskaya et al. 1976; Miller et al.
1993; Welch et al. 2000; Loskutov 2007). In some
accessions, the amount of protein with an increased
lysine content may reach 30%. Such forms have been
found within A. magna and A. murphyi (Ladizinsky
and Fainstein 1977; Ladizinsky 1988; Butler-Stoney
and Valentine 1991; Harder et al. 1992; Leggett
1992a; Welch et al. 2000; Loskutov 2007). The best
indices concerning this trait have been demonstrated
by the accessions of A. barbata from Azerbaijan (over
21%) and Portugal (22.9%). The maximum value of
protein content in grain, i.e., 25.2%, was displayed by
the forms of A. magna and A. murphyi from Morocco
(Miller et al. 1993; Loskutov 2007). When transferring
these characters to cultivated oats, two backcrosses are
sufficient for obtaining stable hexaploid genotypes
(Zadoo et al. 1988). In Sweden, an oat breeding program with an elaborate system of crosses and the use
of backcrosses have been developed for involving
the species A. magna and A. murphyi (Hagberg and
Mattsson 1986). When crossing these species with
cultivated oats, it has been determined that the genes
governing a higher protein accumulation were probably localized in the homeologous chromosomes.
The species A. fatua is considered by many authors
as a good partner in breeding for higher yield and
grain quality (Thompson 1966; Trofimovskaya et al.
1976; Frey 1991; Leggett 1992a). A detailed study of
American populations of this species collected predominantly in the North-Central states of the country
has identified some forms with an increased content of
protein and some amino acids (though the average
concentration of protein was lower than in A. sterilis).
Individual forms of A. fatua (with protein content
above 26%) can serve as donors of these characters
(Rines et al. 1980). The highest average values of
protein content were demonstrated by A. fatua accessions from Ukraine, Georgia, Azerbaijan, Tajikistan,
Poland, and Greece (Loskutov 2007). The hybrid
I.G. Loskutov and H.W. Rines
Table 3.11 Sources of
quality traits in oat species
Species
A. bruhnsiana
A. ventricosa
A. clauda
A. pilosa
A. prostrata
A. damascena
A. longiglumis
A. canariensis
A. wiestii
A. hirtula
A. atlantica
A. strigiosa
A. barbata
A. vaviloviana
A. abyssinica
A. agadiriana
A. magna
A. murphyi
A. insularis
A. macrostachya
A. fatua
A. occidentalis
A. ludoviciana
A. sterilis
A. sativa
Genome
Cv
Cv
Cp
Cp
Ap
Ad
Al
Ac
As
As
As
As
AB
AB
AB
AB?
AC
AC
AC?
СС?
ACD
ACD
ACD
ACD
ACD
plants produced by crossing A. fatua with cultivated
oat had a higher percentage of protein (Reich and
Brinkman 1984). The dark-glume forms with grain
shattering (the wild type) had a lower protein percentage
in the caryopsis and a lower percentage of caryopses
in comparison with the light-colored non-shattering
forms (the cultivated type) (Luby and Stuthman 1983).
According to many authors, the species A. sterilis
possesses and transfers to its progeny the character of
an increased (above 25%) accumulation in grain of
protein with a well-balanced amino acid composition
(Zillinsky and Murphy 1967; Briggle et al. 1975;
Trofimovskaya et al. 1976; Frey 1991, 1994; Leggett
1992a; Welch et al. 2000; Loskutov 2007). A study of
several forms of this species has shown the existence
of a strong correlation between protein content, resistance to crown rust, and other traits (Spilde et al. 1974;
Popovic 1980). It has been proved that in crosses
involving forms of A. sterilis, the content of protein
in the grain of the progeny is influenced not only by
the presence of nuclear genetic material (Browning
Sources of quality
Protein
Oil
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
b-Glucan
Starch
Avenanthramindes
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
þ
and Frey 1972) but also by cytoplasm (Rezai and
Frey 1989a). A study of a large set of A. sterilis
forms has shown that the an increased percentage of
protein in the caryopsis and straw was characteristic of
the accessions from Libya and Iraq (Eagles et al.
1978). The centers of the highest diversity for this
trait were found in the Mediterranean Region, Central
Asia, Middle East, and Israel (Rezai 1978). The highest average values have been displayed by the forms
of A. sterilis from Iran, Israel, Algeria, Morocco,
Tunisia, and Lebanon. A large group of accessions
from Israel has been found to stably accumulate as
much as 23.1–28.0% protein in grain during the years
of the study (Loskutov 2007).
Besides, some forms of the hexaploid species A.
ludoviciana and A. occidentalis have also been characterized by a higher content of protein in the caryopsis (Trofimovskaya et al. 1976; Miller et al. 1993). The
highest average values of protein content in grain
(20–23%) have been recorded for the accessions of
A. ludoviciana from Azerbaijan, Turkey, Iraq, Iran,
3 Avena
Israel, and Algeria. An analysis of protein content in
the grain of A. occidentalis from the Canaries (Spain)
has shown that this species may be promising in
breeding for grain quality (Loskutov 2007).
In hexaploid wild oat species, the protein content in
grain may be as high as 27–28% (Campbell and Frey
1972) and even reach 35% according to some reports
(Frey 1975). A comparison of wild and cultivated
hexaploid species has shown that the percentage of
protein in the caryopsis cross-sections of wild species
was higher, while the content of protein per caryopsis
was lower due to the small size of the caryopsis in wild
species (Youngs and Peterson 1973).
The most promising species from the point of
view of the availability of high-protein forms may
be A. murphyi and A. occidentalis. Among the forms
with high content of protein in the caryopsis, those
belonging to hexaploid species A. fatua, A. ludoviciana, and A. sterilis are promising for breeding
purposes. An analysis of the long-term data for a
correlation between the protein content and the geographic locality of collecting a particular form has
shown that the accessions of hexaploid species with
the highest content of protein in grain originated
predominantly from the Northwest of the African
continent (Loskutov 2007).
Interspecific hybridization proved to be more efficient in breeding for a higher protein content in
grain (Alexander 1975; Axtell 1981; Clamot 1984;
McFerson and Frey 1990). When crossing cultivated
and wild hexaploid species, protein content and yielding ability were found to be inherited independently
(Cox and Frey 1985; Kuenzel and Frey 1985). In both
cultivated and wild species, high protein content was
inherited through recessive genes with additive effect
(Sraon et al. 1975). According to many published data,
a large number of forms of wild oat species have been
analyzed for this trait (Peterson and Brinegar 1986).
This has resulted in the identification of accessions,
which are currently used in oat breeding for developing
highly productive lines and cultivars with an increased
content of protein with a well-balanced amino acid
composition in grain (Lyrene and Shands 1975).
High protein content in grain is important not only
for food but also for forage purposes. At present, the
forms of naked oat are used as forage for cattle, especially in horse breeding. To increase protein concentration in grain of these oat species, wild species are
involved in the breeding process (Valentine 1987).
A study of the nitrogen index (the ratio of nitrogen
content in grain to the total nitrogen in the biomass) in
A. sativa and A. sterilis has established that this index
was on the average higher in the cultivated species,
while in the interspecific hybrids, it exceeded that of
both parents (Fawcett and Frey 1982).
Besides, some forms of wild species had a high
protein content in straw and green matter. Such accessions have been found among the tetraploid A. abyssinica and A. magna and hexaploid A. ludoviciana and
A. sterilis (Mal 1987). The accessions of A. sterilis
collected in southwestern Europe had a higher protein
percentage in straw (Rezai 1978). The absence of a
connection between protein content in grain and in
straw evidences for a possible combination in one
genotype of genes controlling high protein content
(Campbell and Frey 1974; Frey et al. 1975b).
Amino acid composition. Amino acid composition
of proteins in cultivated oat is well balanced. Amino
acid composition of the high-protein tetraploid species
A. magna and murphyi is similar to that of cultivated
oat (Rodionova et al. 1994). The content of individual
essential amino acids was found to be distributed in
the studied wild species as follows: the content of
valine was the highest in A. barbata and the lowest
in A. fatua, that of methionine was the highest in
A. barbata, and that of isoleucine was the highest in
A. barbata and A. sterilis. The content of leucine was
the highest in A. fatua and the lowest in A. barbata,
while the content of tyrosine was higher in A. barbata.
All the studied species had the highest values of phenylalanine accumulation in comparison with cultivated oats; the content of glutamic acid in cultivated
oat was lower than in A. fatua and higher than in
A. barbata, and that of proline was higher in A. ludoviciana and lower in A. barbata. In terms of nutrient
qualities, protein of the tetraploid species A. barbata
should be noted, and in terms of lysine and other
essential amino acids content in protein, hexaploid
species demonstrated values that were at the level of
cultivated oats (Loskutov 2007).
The share of albumins and globulins in hexaploid
species A. sterilis, A. ludoviciana, and A. fatua was
1.5–2 times lower than in cultivated species, while, on
the contrary, the percentage of the alkali-soluble proteins was higher in the three former species. It means
that the total protein nutrient value in wild species was
lower than that of cultivated species (Trofimovskaya
et al. 1976). According to many authors, A. sterilis has
I.G. Loskutov and H.W. Rines
and transmits the trait of the well-balanced amino acid
composition of protein in grain to its progeny (Briggle
et al. 1975; Frey 1991; Leggett 1992a).
The correlation analysis has found regularities in
accumulation of protein and individual amino acids in
oat grain. It should be noted that the content of all
essential amino acids (except for methionine) correlates closely and positively with the content of protein
(0.78–0.94) and lysine (0.62–0.80). The existence of a
correlation between the content of protein and lysine
in grain protein has been determined in 60.1% of the
cases, thus making it possible to carry out preliminary
selection of the high-lysine forms on the basis of total
protein in grain (Loskutov 2007).
Fats. In addition to protein, oat grain is rich in
other chemical compounds and fats in particular
(Table 3.11). A search for genes capable of improving
this trait in cultivated oat while maintaining the stability of yield level has not achieved the desired results so
far. Besides, it has been established that the genes
controlling this trait in cultivated and wild species
are not allelic (Thro and Frey 1985; Frey 1991). Interspecific hybridization proved to be more efficient in
breeding for this trait. In some diploid and tetraploid
species, the content of oil in the caryopsis reaches
12–13% (Welch and Leggett 1997). The majority of
studied forms of such species as A. clauda, A. pilosa,
A. canariensis, A. longiglumis, A. damascene, A. wiestii, A. hirtula, A. atlantica, A. agadiriana, A. barbata,
and A. vaviloviana had the caryopsis oil content above
7% (Welch et al. 2000; Loskutov 2007; Leonova et al.
2008).
A high content of oil in grain has also been
recorded for the tetraploid species A. magna and A.
murphyi (Ladizinsky 1988; Welch et al. 2000; Leonova
et al. 2008). The highest average values for this trait
in A. barbata has been demonstrated by its accessions
from Azerbaijan, Spain (the Canaries), and from Italy.
The highest average values of oil content in grain
have been registered for the forms of A. magna and
A. murphyi from Morocco (Loskutov 2007).
In A. ludoviciana and A. fatua, the content of oil
in grain reached 7–9% (Trofimovskaya et al. 1976;
Leonova et al. 2008). The highest average values for
this trait were displayed by accessions of A. fatua
from Ukraine, Kazakhstan, and Tajikistan. The highest average values for oil content in grain (9.7–11.1%)
were discovered in accessions of A. ludoviciana from
Azerbaijan, Georgia, and Armenia. The percentage of
oil (above 7.8%) in grain of a form of A. occidentalis
from the Canaries (Spain) indicated that this species
may be promising in breeding for grain quality (Welch
et al. 2000; Loskutov 2007). On the average, a hexaploid A. sterilis has been found to have a high fat
content (upto 10%) in grain (Thro 1982; Frey 1991,
1994; Leggett 1992a; Welch et al. 2000; Leonova et al.
2008). The largest number of samples with such characteristics has been collected in Israel (Rezai 1978). A
group of accessions with oil content in grain in the
range of 8.3–10.7% has been found to include forms
of A. sterilis from Iraq, Israel, Japan, and Algeria
(Loskutov 2007).
The percentage of oil in hybrid plants produced by
crosses with said species increases (Frey 1991). The
dark-glume, shattering forms have been noted to have
low percentage of oil in grain and low percentage of
grain in comparison with the light-colored, non-shattering forms (Luby and Stuthman 1983). This trait is
controlled polygenically and shows incomplete dominance. The additive nature of gene action, high heritability, and a close and positive link between the
general combining ability (GCA) effects and oil content in the caryopsis have been noted (Elliott et al.
1985). The hybrids involving cultivated oat may be
transgressive (Frey et al. 1975a). The main method
of transferring the trait of high oil content from
wild to cultivated species is recurrent breeding. Since
the alleles for high oil content from A. sativa and
A. sterilis are complementary (Thro and Frey 1985),
a program to improve the oil content by using recurrent selection was carried out that resulted in increases
in groat oil concentration of upto 18% in relatively
short time (Branson and Frey 1989a, b; Frey and
Holland 1999; Schipper and Frey 1991).
Fatty acid composition of oil. The oil contained in
grain of wild hexaploids practically does not differ
from that of cultivated species: oleic and linolenic
acids are the main ones in its composition, the content
of the latter being sometimes lower or higher than that
of oleic acid. The total polyunsaturated acids fit the
amplitudinal range of cultivated species. Therefore,
the oil content differentiates the wild from cultivated
species more than the fatty acids ratio in the oil
(Trofimovskaya et al. 1976). The highest content of
oleic acid is characteristic of the diploid species A. damascena, A. longiglumis, A. canariensis,
A. atlantica, A. hirtula, and A. wiestii, of the tetraploid
ones: A. barbata, A. vaviloviana, A. murphyi, and
3 Avena
A. magna, and of the hexaploid species A. occidentalis, A. fatua, A. sterilis, and A. ludoviciana (Welch
et al. 2000; Loskutov 2007; Leonova et al. 2008). At
the same time, biological activity of such oil is determined by the linoleic to oleic acid ratio, which should
equal 1.0. Such a value was displayed by the diploids
A. ventricosa, A. clauda, and A. pilosa and by the
tetraploid A. vaviloviana (Loskutov 2007).
A correlation analysis has shown that an increase in
the content of saturated (palmitic and stearic acids)
and monounsaturated (oleic) fatty acids in oil of wild
oat species will be accompanied by the decrease in
the content of polyunsaturated fatty acids, which oxidize easily during grain storage (Loskutov 2007).
Crosses of the forms with high and low content of
linoleic acid have shown that inheritance of linoleic
and oleic acids was oligogenic (Karow 1984). Other
authors believe that inheritance of palmitic, oleic, and
linoleic acids are controlled polygenically with additive effect and that inheritance is partially dominant
(Thro 1982).
Starch. An important aspect determining grain
digestibility is the presence of starch in it (Table 3.11).
A content of amylose comparable with that in
cultivated oats has also been recorded in the wild
species A. sterilis, A. ludoviciana, and A. fatua. These
data evidence closeness of starch composition in
cultivated and wild oat species (Rodionova et al. 1994).
b-glucans. The (1–3) (1–4)-b-D-glucan, or the nonstarch water-soluble polysaccharide b-glucan, is
regarded as a physiologically important dietary component of grain (Table 3.11). The data on this trait in
wild oat species are very small as compared to the
cultivated ones. Among diploid species, an increased
content of b-glucans has been noted for A. strigosa and
A. hirtula (4.6–5.5%), A. damascene, A. longiglumis,
and A. atlantica. In such tetraploids as A. agadiriana,
A. barbata, A. magna, and A. murphyi, this value was
around 3.2% on an average (Miller et al. 1993; Leggett
1996; Howarth et al. 2000; Welch et al. 2000). A study
of a limited set of accessions of wild species including A. sterilis has shown that all hexaploid species
(A. fatua, A. occidentalis, A. byzantina) had a higher
content of b-glucans (upto 6%) in grain (Frey 1991;
Welch et al. 1991; Cho and White 1993; Miller et al.
1993). Groat b-glucan concentration in wild species
showed very wide variation (2.2–11.3%) as there were
substantial interspecific and intraspecific differences
(Welch et al. 2000).
Vitamins. Oat contains different vitamins, including the fat-soluble vitamin E (tocopherol and tocotrienol), which possesses increased antioxidant properties.
The data on this trait in wild oat species are extremely
poor. A study of the influence of different mutagens on
oats has found that the high content of tocopherols in
A. ventricosa plants can be explained by a lesser
sensitivity of this species to physical and chemical
mutagenic damage in comparison with the affined
species A. bruhnsiana, which has a low content of
tocopherols and a more narrow distribution range in
comparison with the former species (Alekperov 1982;
Alekperov and Sinitsina 1982).
A study of nutritional properties of oats from India
has identified a number of species with a decreased
content of lignin and silica compounds in green matter
thus suggesting their suitability for consumption by
animals. Among these species are the diploids A. strigosaand A. ventricosa, tetraploids A. barbata, A. vaviloviana, and A. abyssinica, and hexaploids A. sterilis
and A. ludoviciana (Mal 1987).
Thus, it has been established that the wild species
A. magna, A. sterilis, and A. ludoviciana are the most
promising and important ones in terms of grain quality
and the transfer of this trait to cultivated oats. Besides,
there also exist other sources of various traits related to
grain and green matter quality, which may be successfully used for improving these characters in cultivated
oats.
3.5.2 Use of Wild Oats in Crop
Improvement: Challenges,
Approaches, and Successes
The tremendous potential of wild Avena species as
donors of genes for a wide spectrum of biotic and
abiotic traits is evident from the preceding deliberations of numerous species sources harboring resistance for various oat pathogens and wide ranges of
variation in other quantitative traits. The transfer,
capture, and sustainable use of these traits in oat
cultivar development and releases can prove challenging for from genetic techniques to breeding line
selection, especially with transfer from lower ploidy
species. This section describes genetic and breeding
approaches employed with different Avena species as trait sources, breeding line development
I.G. Loskutov and H.W. Rines
including examples of cultivars released with transferred improved traits, some difficulties and limitations encountered, and how use of molecular markers
can facilitate transfer and selection.
The ease of transfer and the utility of the variation
identified in wild and lower ploidy Avena species
accessions depend on the nature of variation, whether
qualitative or quantitative, and the genetic relationship
between the alien donor and the recipient cultivated
species. Qualitative variation, such as disease resistance when controlled by major genes, is often simply
inherited and readily scorable independent of genetic
background and growth environment. Quantitative
variation, such as is observed for many agronomic
and seed quality traits, in contrast, is often controlled
by multiple genes and its expression is strongly influenced by genetic background and the growth environment. Oat cultivars with a portion of wild oat
germplasm in their parentage and with enhanced quantitative traits have been released where the enhanced
trait is attributed to the wild oat germplasm component. This attribution is often based on an enhanced
level of that component in the wild germplasm donor.
The extent of trait contribution, however, and even the
amount of wild species germplasm genome present
after rounds of crossing and selection cannot currently
be documented. The use of gene- and genome-specific
DNA markers will not only aid tremendously in the
identification and transfer of quantitative trait loci
(QTL) for these traits from wild species sources
but also enable documentation of their presence and
contribution.
As discussed in Sect. 3.4, the species of Avena have
been assigned into three gene pools – primary, secondary, and tertiary – by Leggett and Thomas (1995) based
on the ease of transfer (introgression) of genes from
alien species into cultivated hexaploid oat according to
the concept of gene pools for cultivated species proposed by Harlan and de Wet (1971). In this system, the
primary gene pool consists of all the hexaploid species,
the secondary pool of the tetraploid AACC species
A. magna, A. murphyi, and A. insularis, and the tertiary
pool the diploid species and the remaining tetraploid
species. In Avena, the transfer of traits has been mostly
from within the primary gene pool. Even there, documented contributions to cultivar development have
been restricted primarily to qualitatively inherited
major genes for disease resistance where trait detection
is more readily accomplished.
3.5.2.1 The Primary Gene Pool
All the hexaploid oat taxa, including the most common
wild oats A. sterilis and A. fatua, were grouped into
a single biological species with cultivated oats by
Ladizinsky and Zohary (1971) because of their high
interfertility in crosses. Thus, the hexaploids constitute
the primary gene pool for transfer of desired traits to
cultivated hexaploid oat. Because of the high interfertility, the introgression of traits from the wild
hexaploid can be accomplished fairly readily by conventional crossing and backcrossing procedures. However, greater frequencies of meiotic abnormalities,
such as univalents and micronuclei, were observed in
wild/cultivated species hybrids of A. sterilis/A. sativa
by McMullen et al. (1982) and in A. fatua/A. sativa by
Luby et al. (1985) than in intraspecific hybrids. These
higher frequencies indicate that in spite of high interfertility, there are likely reductions in recombination associated with meiotic irregularities due to
chromosomal heteromorphology between the wild
and cultivated hexaploid oats. These irregularities
could hinder breaking of linkages between useful
and deleterious genes during wild to cultivated oat
introgression.
A. sterilis, the progenitor species of cultivated oat,
has been found to be quite a rich source of diverse
traits, particularly disease resistance, for use in oat
breeding programs (Frey 1985). In the spring, in oat
regions of the midwest US and the eastern prairie
regions of Canada, and also in the winter oat regions
of the southern US, where crown rust (P. coronata f.
sp. avenae) periodically can devastate oat production,
most oat breeding programs have become reliant on
the use of crown rust resistance (Pc) genes from A.
sterilis in their cultivar releases. More than 30 of these
Pc genes from A. sterilis have been identified and
backcrossed into susceptible oat lines to form sets of
differentials that are used to monitor changes in rust
virulence patterns (Chong et al. 2000; Carson 2008).
However, most of the Pc genes used to-date have been
major genes providing rust race-specific resistance.
Thus, when deployed singly, though initially highly
effective in protecting the cultivar, they can rapidly
lose their effectiveness due to high selection pressure
causing shifts in the rust population’s virulence pattern. Various schemes have been developed over the
years to try to extend the effective use of these genes.
In the Canadian oat breeding programs, an A. sterilis
3 Avena
gene, Pc39, added singly in the cultivar Fidler
(McKenzie et al. 1981) provided crown rust resistance
that was improved compared to that of other cultivars
when the cultivar was released. Later, combining Pc38
and Pc39 in the release “Dumont” (McKenzie et al.
1984) conferred resistance to all known crown rust
races at the time. This Pc38–Pc39 combination
together with possible other non-identified A. sterilis
genes was used in many other Canadian releases and
in North Dakota releases including “Steele,” “Valley,”
and “Newdak” (McMullen and Patterson 1992). The
Pc38–Pc39 combination provided effective resistance
until it was finally overcome around 1990 (Chong and
Seaman 1991). The addition of Pc68 to Pc38–Pc39 in
“AC Assiniboia” (Brown et al. 2001), “AC Medallion”
(Duguid et al. 2001), and several subsequent releases
provided protection for several additional years, but
this combination too lost effectiveness with race shifts
to virulence on Pc68 (Chong et al. 2008). This breakdown necessitated a search for additional sources of
resistance including new A. sterilis lines for use in
combined or stacked combinations. Winter oat breeding programs in the southern US made use of other
A. sterilis-derived Pc genes for crown rust resistance
including Pc58 in “TAM-0-301” (McDaniel 1974a)
and Pc59 in “TAM-0-312” (McDaniel 1974b), two
releases from Texas A&M University, and Pc60
and Pc61 in releases by the Coker’s Pedigree Seed
Company in South Carolina (Leonard and Martinelli
2005). Pc60 and Pc61 subsequently also were used in
spring oat cultivars “Don” (Brown and Kolb 1989a)
and “Hazel” (Brown and Kolb 1989b), respectively,
released from Illinois.
An alternative method of deploying crown rust
resistance genes, including numerous ones from A.
sterilis, to extend the effective life of individual resistance genes was the “multiline” approach utilized by
K.J. Frey, J.A. Browning, and M. D. Simons at the
Iowa State University (Browning and Frey 1969). In
this approach, different crown rust resistance genes
were introgressed into a common oat cultivar or line
to form a rust gene composite cultivar of otherwise
agronomically similar lines. The deployment of this
multiline should then put less selective pressure on the
rust population to develop resistance to any particular
resistance gene. In the multiline cultivar “Webster,”
all nine resistance genes used were from A. sterilis
(Frey et al. 1988). While this approach appeared to
be effective in delaying or preventing a build-up of
virulence on specific genes, it proved too slow and
cumbersome to make adequate continued progress on
all the other traits involved in a cultivar improvement
program and thus has not been widely utilized.
In addition to the named Pc genes, many other
instances have been reported on transfer of crown
rust resistance genes from A. sterilis into oat germplasms and cultivars. Many of these provide adult
plant partial resistance and are quantitative and multigenic, and hence more difficult to characterize, but
may be less race-specific and hence more durable in
effectiveness (Simons 1985). For example, Hoffman
et al. (2006) have shown that the Pc58 resistance of
“TAM-0-301” entails at least three genetically separable components including one showing possible nonrace-specific partial resistance.
Crown rust resistance from A. sterilis has been
used in oat improvement in other countries besides
the US and Canada, either from direct crosses with
A. sterilis or indirectly using A. sterilis-containing
germplasm from the US or Canada. Of particular
note in this regard is the likely presence in various
South American cultivars with Pc58, Pc59, Pc60,
and P61 introduced through the Quaker International
Oat Nursery, which has been grown for many years
in several South American countries (Leonard and
Martinelli 2005).
Two genes, Pg13 and Pg15, conferring resistance
to the other major rust of oat, stem rust (P. graminis f.
sp. avenae), are included in the set of differentials
currently used to characterize stem rust virulence in
the US and Canada (Fetch and Jin 2007). Pc13 combined with Pg2 and Pg9, when used in developing
“Dumont” (McKenzie et al. 1984) and several subsequent cultivar releases from the Winnipeg group
and in “Steele” (McMullen and Patterson 1992) and
subsequent releases from North Dakota, provided
effective resistance to the prevalent stem rust races in
those regions for several years. However, a rapid rise
in prevalence of races with virulence on Pg13 in those
regions in the late 1990s necessitated a search for
new resistance gene sources (McCallum et al. 2000).
Screening of almost 7,000 A. sterilis accessions failed
to identify any source with strong resistance to the
current prevalent stem rust race in that region, but
resistance was found in accessions of lower ploidy
oat species (Gold Steinberg et al. 2005).
The use of A. sterilis as a source of resistance to
oat powdery mildew (Blumeria graminis (DC.) Speer
I.G. Loskutov and H.W. Rines
f. sp. avenae Em. Marchall) in Britain and continental
western Europe was included in a review by Roderick
et al. (2000). Powdery mildew is described as the
most important foliar pathogen of oats in Britain
and in the cooler, humid regions of western Europe.
Resistance from A. sterilis (var. ludoviciana) Cc4346
was introduced in the cv. Mostyn in Britain; however, the effectiveness of this race-specific gene
was overcome within a few years by a shift in pathogen virulence, although it remained effective for a
few additional years in continental Europe. Similarly,
the release of cv. Maris Tabard with the resistance
gene from an A. sativa A. sterilis (var. ludiviciana)
hybrid resulted in a pathogen virulence shift within
a few years. An apparently more durable form of
powdery mildew resistance expressed as a partial or
adult plant resistance was discovered in the line
PC54, which had been developed with a crown rustresistant gene, Pc54, differential by backcrosses of
A. sterilis CAV1832 into A. sativa cv. Pendak
(Sebesta et al. 1993). This source became the main
for powdery mildew resistance deployed in British
and European oat breeding programs (Roderick et al.
2000).
Resistance transferred from A. sterilis into cultivated oats has also been documented for cereal cystnematode Heterodera avenae Woll. (Cook 1974).
Nullisomic analysis indicated that the dominant resistance gene in the oat cultivar “Panema” derived from
A. sterilis line I.376 appeared to be at the same locus as
the one in cv. “Nelson” derived from A. sativa CI 3444
(Chew et al. 1981). Nematode resistance from A. sterilis was also used in developing cultivars at Svalof,
AB, Sweden (Mattsson 1988).
In addition to being a rich source of genes for
disease resistance, A. sterilis accessions have been
characterized, which have other agronomic and seed
quality traits of value in cultivated oat improvement.
Most of these traits, however, are quantitative in
nature, controlled by multiple genes and with expression influenced by the genetic background and the
environment. Thus, the transfer of these traits into a
desirable cultivated oat type is much more challenging than that for qualitative major genes, which often
can be introgressed simply by backcrosses to a recurrent parent cultivar with minimal impact on other
traits of the recipient. In his review on oat improvement, J. B. Holland (1997) pointed out that transfer
of a polygenic quantitative trait from a wild oat
species usually requires larger amounts of wild germplasm to be maintained in the resulting breeding lines
than transfer of a single gene trait. Thus, the transfer
of quantitative traits fits more into the concept developed by Simmonds (1993) of “incorporation” of
exotic germplasm versus simple “introgression” of a
single trait.
Another problem for incorporation of quantitative
traits from wild germplasm besides potential linkage
drag of deleterious genes is the same as for incorporation of such traits from any germplasm source – a
resulting undesirable correlated change in other traits
in the resulting lines. For example, groat (karyopsis)
protein as high as 35% was identified in some A.
sterilis accessions (Campbell and Frey 1972; Ohm
and Patterson 1973; Frey 1983) but proved difficult
to capture in high grain yielding breeding lines due to
the well-known negative association between these
characters in cereals (Simmonds 1995). This complication arises due to competition between physiological
processes for a limited pool of nitrogen and carbon
metabolites. Also, apparent high levels of grain components such as protein, oil, b-glucan, or other nutrients are often expressed on a percentage basis such
that thin-kernels with low starch content appear
deceivingly favorable. In spite of these problems,
germplasm and breeding lines with enhanced levels
of seed composition traits have been produced from
A. sterilis–A. sativa hybridizations (Frey 1992).
In his review, Holland (1997) pointed out that
recurrent selection has proven to be a technique particularly well-suited for incorporating genes from A.
sterilis into adapted gene pools due to the opportunities to break linkages to undesirable traits through
successive rounds of recombination and selection. He
then described two examples from the extensive work
of Frey and his students at the Iowa State University
on the use of recurrent selection using A. sterilis germplasm to generate high protein and high oil oat breeding lines.
Several progressive studies were involved in the
incorporation of high groat protein from A. sterilis
including the demonstration that some high-protein
genes from A. sterilis were different from and complementary to those in A. sativa (Cox and Frey 1985), the
identification of several mating lines involving both A.
sterilis and A. sativa germplasm in which there was
little or no negative correlation between grain protein
percentage and groat yield (Kuenzel and Frey 1985),
3 Avena
AU20
AU21
and the selection of progeny from those matings and
their use as the source parents for cycles of recurrent
selection for high grain protein yield (grain yield
protein percentage) (McFerson and Frey 1991; Moser
and Frey 1994). A similar progressive set of experiments were conducted to use A. sterilis germplasm in
the development of high groat oil concentration oat
breeding lines with first the demonstration that genes
for high groat oil content from A. sterilis are complementary to those from A. sativa (Thro and Frey 1985),
then crossing of high oil A. sterilis accessions to high
oil A. sativa lines followed by crosses to agronomically superior A. sativa cultivars with cycles of recurrent selection for high oil content with independent
culling for agronomic adaptation and cultivated plant
type (Branson and Frey 1989a, b). These efforts
resulted in lines after cycle 6 with oil content over
16% (Schipper and Frey 1991).
The presence of yield enhancing genes from A.
sterilis were reported by Frey and Browning (1971)
based on increased yields of some of the lines derived
from crosses made to introgress crown rust resistance
genes from A. sterilis into A. sativa. Enhanced yield
was also found in backcross F2 generations of several
other A. sterilis A. sativa crosses by Lawrence and
Frey (1975). Further studies of such materials indicated that the enhanced yield was likely attributable
to enhanced growth rate (Takeda and Frey 1976),
increased biomass (Cox and Frey 1984a, b), and
greater leaf area duration (Brinkman and Frey 1977;
Bloethe-Helsel and Frey 1978).
Several cultivars with improved traits and containing large amounts of A. sterilis germplasm have been
released including “Sheldon” (Frey 1992) and Ozark
(Bacon 1991). In these lines, high yield potential and,
in Ozark, winter hardiness have been attributed, at
least in part, to contributions from the A. sterilis component. Similarly, although no specific genes for barley yellow dwarf virus (BYDV) tolerance (inherited as
a polygenic trait) were identified, the finding of BYDV
tolerance or resistance in almost half of 1,718 A.
sterilis accessions tested led Comeau (1982) to postulate that many of the recent cultivars in USA and
Canada derive some BYDV resistance factors from
A. sterilis.
Enhanced yield was also observed in early backcross generation lines, which contained A. sterilis
cytoplasm when the lines were compared to derived
lines from reciprocal crosses involving the same
A. sterilis–A. sativa parents but with A. sativa cytoplasm (Robertson and Frey 1984). This observation
led them to propose use of A. sterilis cytoplasm for oat
cultivar improvement. However, failure to find evidence of a consistent nuclear–cytoplasm heterotic
effect across numerous A. sterilis–A. sativa matings
(Beavis and Frey 1987) and in later backcross generations of A. sterilis–A. sativa matings (Rines and
Halstead 1988) indicated that the positive effect of
the A. sterilis cytoplasm was specific depending on
the accession combination and the A. sterilis nuclear
genes retained in each line.
The other common wild hexaploid oat, A. fatua L.,
has been used to a much lesser extent than A. sterilis as
a germplasm source for oat improvement. This
reduced use is probably because of its lack of identified major genes for disease resistance and overall lack
of diversity of traits as found in A. sterilis. A. fatua
germplasm was a major component of releases of
the cultivars “Rapida” (Suneson 1967a), “Sierra”
(Suneson 1967b), “Montezuma” (Suneson 1969), and
“Mesa” (Thompson 1967). The use of locally collected A. fatua as parents provided desired adaptation
characteristics for the arid regions of the southwest
US including extreme earliness in Rapida and
Montezuma. Stevens and Brinkman (1986) were less
successful in the use of A. fatua accessions to improve
yield performance in crosses to Midwest US cultivars.
One backcross selection did outyield its recurrent
parent but lacked straw strength and crown rust resistance as required for cultivar release.
Several dwarfing genes were identified in short
statured A. fatua plants collected in Japan and the
surrounding areas of eastern Asia when these plants
were crossed to cv. Kanota by Morikawa 1989 and
Morikawa et al. (2007). However, when one of these
genes was used in further crosses by Milach et al.
(1998), the resulting dwarf phenotype was found to
be too extreme to be directly used in cultivar development. Further efforts to identify appropriate
modifier genes or the use of other of the identified
dwarfing genes might prove useful in developing
reduced height oat cultivars. An uncharacterized
gene (or genes) for dormancy in A. fatua accessions
was used by Burrows (1986) to develop experimental
lines (termed “dormants”) of cultivated oat that
could be planted in the fall, lie dormant over winter,
and then germinate in early spring to take advantage
of a longer growing season in the northern regions
I.G. Loskutov and H.W. Rines
where oats do not successfully overwinter. Adequate
synchrony of germination combined with good cultivated oat phenotype proved difficult to attain for use
in cultivar release.
3.5.2.2 The Secondary Gene Pool
Leggett and Thomas (1995) defined the secondary
gene pool as the AACC tetraploid species A. magna
(maroccana) and A. murphyi based on observations
that, although in hybridizations with A. sativa the F1
plants are highly self-sterile, F1 female fertility
enables crossing to hexaploid to produce low seed
set, and pairing between chromosomes of the tetraploid and hexaploid species seems sufficient to allow
recombination to occur. A. insularis, a more recently discovered AACC tetraploid (Ladizinsky 1998)
should also be included in this secondary gene pool.
The capability to transfer genes from the AACC tetraploid to hexaploid cultivated oat was indicated by the
recovery of derivatives of backcrosses of the pentaploid F1 having 42 chromosomes but with traits characteristic of the tetraploid parent (Ladizinsky and
Fainstein 1977; Thomas et al. 1980a).
The successful introgression of crown rust resistance from an A. magna accession into a hexaploid
cultivated oat germplasm was accomplished by Rothman (1984) through the use of a synthetic hexaploid.
The synthetic hexaploid was derived from a colchicine
treated F1 hybrid between diploid A. longiglumis
accession CW57 and A. magna accession CI 8330.
Although the initial C1 (progeny of colchicine-treated
F1) plant set few seed, a C6 segregants with cultivatedtype spikelet components and stable fertility was
recovered, perhaps through accidental outcrossing.
This germplasm containing the resistance gene Pc-91
(Rooney et al. 1994) was used in developing the cultivar HiFi (McMullen 2005), which, due to the presence
of Pc91 together with some unidentified Pc genes,
has retained its effective resistance for several years
(Chong et al. 2008).
Features of A. magna that provoked the initial
interest in transfer of genes to cultivated oats was the
large groat size and high groat protein content (over
25%) in certain accessions (Ladizinsky and Fainstein
1977; Thomas et al. 1980a). In spite of extended
crossing, backcrossing, and selection efforts, successful incorporation of these polygenically inherited traits
into high-yielding cultivars has not proven possible
(J. Valentine personal communication, Aberystwyth
Univ., UK). As an alternative to trying to transfer
these complex polygenic traits into hexaploid
cultivated oat, Ladizinsky and Fainstein (1977a) proposed transfer of more simply inherited domestication
traits from A. sativa into A. magna and A. murphyi to
produce a domesticated tetraploid oats. Ladizinsky
(1995) reported transfer of the characteristics of nonshedding spikelets, glabrous and yellow lemma, and
reduced awn formation into tetraploids with each of
the characteristics segregating in an apparent single
gene manner. He further pointed out that such transfers into otherwise A. magna and A. murphyi genetic
backgrounds might make domesticated derivatives
more successful than common oat in the warm habitats
of Morocco and Spain where these wild tetraploid
species grow naturally.
3.5.2.3 The Tertiary Gene Pool
The tertiary gene pool as defined by Leggett and
Thomas (1995) consists of all the diploid Avena species and the tetraploids A. barbata, A. vaviloviana, A.
abysinnica, and A. macrostachya. Characteristic of
this more difficult to exploit group is that members
do not readily hybridize with A. sativa to produce F1
plants, F1 plants when produced are highly sterile both
in self-fertilization and in backcrosses to the F1, and
the introduced desired traits are usually difficult to
introgress into stable cultivated breeding lines free of
accompanying deleterious genes.
Use of the lower ploidy parent as female in crosses
usually enhances the frequency and quality of seed set
(Rajhathy and Thomas 1974). Even then, embryo rescue is often required in many diploid hexaploid
crosses to recover F1 plants. Some level of fertility in
these highly sterile interspecific F1 plants, presumably
resulting from a lack of chromosome homology and
subsequent lack of chromosome pairing, is often
attained by treating the plants with colchicine to double the chromosome number, thus producing plants
with the full sets of chromosomes from both parents.
Backcrossing of these chromosome-doubled lines to
A. sativa as recurrent parent with selection for the
introduced desired trait often produces gradually
increasing fertility to lines similar to the recurrent
parent with the trait introgressed or with the trait
3 Avena
present on an added or substituted chromosome or
chromosome pair. Examples of successful trait introgression using synthetic octaploids from embryorescued colchicine doubled F1 plants from diploid
hexaploid crosses include introgression of powdery
mildew resistance from A. pilosa by Hoppe and
Kummer (1991), now in the recently released cultivar
“Champion” (M. Herrmann, BAFZ, Gross Lusewitz,
Germany, personal communication 2009), and crown
rust resistance Pc94 by Aung et al. (1996), now in the
cultivar “Leggett” (Chong et al. 2004).
Several other “bridging” schemes have been used
to transfer genes, usually for rust resistance, from
diploids to A. sativa. These involve incorporating the
resistance into a tetraploid or synthetic hexaploid that
will produce a viable F1 in crosses to A. sativa and
include production of a colchicine-doubled autotetraploid of the diploid (Zillinsky and Derick 1960), introgression of the rust gene from the diploid into a
tetraploid species (Zillinsky et al. 1959), and construction of a synthetic hexaploid by crosses of the diploid
to a tetraploid followed by colchicine doubling to
construct a synthetic hexaploid. These latter 2x þ 4x
synthetic hybrids have been made both with AABB
(AAA0 A0 ) tetraploids such as A. abysinnica (Brown
and Shands 1954; Forsberg and Shands 1969a, b) and
AACC tetraploids A. magna (Rothman 1984) and A.
murphyi (Rines et al. 2007). The 2x · 4x synthetic
Amagalon from A. magna A. longiglumis also permitted access to the crown rust resistance gene Pc91
(Rothman 1984) from the tetraploid A. magna, now in
cv. HiFi (McMullen 2005).
The next difficulty frequently encountered in gene
transfer from a diploid or tetraploid oat species into
common cultivated oat is to integrate that gene into
breeding lines stable for transfer of the added gene
through generations and free of deleterious linkage
effects. Dyck and Zillinsky (1963) reported two
crown rust resistance genes originally from A. strigosa
CD3820 present in different selections from crosses of
a derived tetraploid to A. sativa. One of these, Pc23,
appeared to be completely incorporated into the normal sativa lines and was transmitted in a stable fashion. The other, Pc15, was inherited in an unstable
fashion. They suggested that, based on cytological observations of varying frequencies of pairing
between A. strigosa and A. sativa chromosomes in A.
strigosa A. sativa hybrids, there were segments of
diploid chromosomes (e.g., the one carrying Pc15)
not fully compatible with the sativa chromosomes
and thus responsible for the irregular meioses. Comparative analyses between molecular marker maps
of A genome diploids and A. sativa revealed larger
syntenic regions to A. sativa linkage groups with
some of the diploid linkage groups than with others
(O’Donoughue et al. 1995; Portyanko et al. 2001).
Also, Jellen et al. (1995) found that certain chromosomal linkage groups tended to remain more syntenic
across cereals than others. Thus, the possibility or ease
with which a foreign gene (e.g., from A. strigosa) is
incorporated cleanly into a chromosome of the recipient species likely depends on the location of the gene
in the donor genome and the retained homoeology of
that donor chromosome or chromosome segment to a
chromosome of the recipient species. For example,
Rines et al. (2007) obtained normal male and female
transmission of a crown rust resistance gene (Pc94) in
42-chromosome derivatives in transfers from A. strigosa CI6954SP into an “Ogle” oat background.
Loss in further backcrosses of a molecular marker
SCAR94-2 (developed by Chong et al. 2004) linked
about 5 cM from Pc94 in other backcross lines indicated that meiotic recombination was occurring in
the region. Field tests of backcross 6 lines revealed
no evidence of linkage drag of any detrimental traits
(H. Rines unpublished). In contrast, several efforts
were made over years to incorporate into stable lines
the Pc15 resistance from A. strigosa CD3820 by selfing
or backcrossing of strigosa-derived materials. Paired
cytological and resistance transmission studies revealed
that the resistance was always associated with a
retained alien addition, substitution, or telosomic chromosome and transmitted unstably, usually only through
the female gamete. Irradiation of an alien monosomic
substitution allowed recovery by Sharma and Forsberg
(1977) of a stably transmitting line, presumably from
translocations from the alien substitution chromosome
to a non-homoeologous chromosome. The performance
of three cultivars “Centennial,” “Horicon,” and “Dane”
with resistance derived in this manner indicates that
derivatives can be produced by this approach and further selection with no accompanying significant deleterious effects (Forsberg 1990).
Difficulties have also been encountered in transferring desired genes cleanly from tetraploid species of
this secondary gene pool, again presumably due to
chromosomal heteromorphology between the donor
species and A. sativa. Attempts to transfer mildew
I.G. Loskutov and H.W. Rines
AU22
resistance from tetraploid A. barbata (Cc4897) to cv.
Manod through backcrossing and selection resulted
only in lines with the resistance carried on an alien
addition chromosome (Thomas et al. 1975). Irradiation of the addition line with a CO60 source enabled
recovery of a resistant translocation line with normal
transmission of the resistance in the “Manod” background, but the translocation showed irregular transmission in certain other cultivar backgrounds. This
translocation was shown to involve exchange between
non-homoeologous chromosomes (Aung and Thomas
1978). Transfer of stem rust resistance from A. barbata by irradiation of alien chromosome additions was
similarly accomplished by Brown (1985) producing
relatively stably transmitting translocation lines, but
with accompanying yield reductions, presumably due
to the presence of deleterious genes on the translocated
alien segment. More stably transmitting mildewresistant breeding lines were produced by Thomas
et al. (1980b) who employed through crosses the action
of a “suppressor” of non-homoeologous chromosome
pairing present in A. longiglumis CW57. The use of
CW57 to induce homoeologous pairing of desirable
alien variation into cultivated oat and thus enhanced
introgression is discussed by Thomas and Al-Ansari
(1988). That the diploid oat component of the “Amagalon” synthetic hexaploid in the earlier described
transfer of crown rust resistance from A. magna by
Rothman (1984) was A. longiglumis CW57 may
account for his success in the recovery of a stable
sativa-like resistant derivative. The CW57 line was
also used to facilitate transfer of a dominant gene
conferring mildew resistance from diploid oat A. prostata (Griffiths 1984; Morikawa 1995). Successful
introgression of powdery mildew resistance from the
perennial tetraploid oat A. machrostachya, however,
was accomplished simply by various crosses and
selection (Yu and Herrmann 2006).
Of interest relative to the degree of homology of an
introduced alien chromosome segment relative to chromosomes of the recipient is not only its initial pairing
and recombination with one of the recipient cultivated
oat chromosomes but also the disruptive effect the introgressed segment may have on meiotic pairing once it is
introgressed. Wilson and McMullen (1997a, b) reported
that the introgressed A. sterilis crown rust resistance
gene Pc38 was located on one chromosome in the cultivar “Steele” but on a different chromosome in cultivar
“Dumont” such that in crosses of “Steele” “Dumont”
the two sites could segregate producing progeny with
0 to 4 copies of Pc38. The alternative site in “Dumont”
apparently was generated as a result of a reciprocal
interchange presumably involving homoeologous sativa
chromosomes. Similarly, the location of another introgressed alien chromosome segment, Pc94 from
A. strigosa CI6954SP, has been found at independently
segregating sites in various backcross derived lines,
again indicating possible occurrence of a translocation
between homoeologous sativa chromosomes caused
by abnormal meiotic pairing involving the introgressed
alien chromosome segment (H. Rines unpublished).
Another obstacle that can arise in interspecific trait
transfer and which can occur across all levels of ploidy
transfer is a suppression or inhibition of expression of
the introduced trait. This suppression may be either a
gene-specific or a general species-specific suppression
and has been observed in many crops including wheat
(Singh et al. 1996). A crown rust resistance gene Pc38,
or some factor closely linked to it, was reported to
suppress the resistance of another A. sterilis-introduced
gene Pc62 (Wilson and McMullen 1997a, b) and also
a resistance gene Pc94 introduced from A. strigosa
(Chong and Aung 1996). Rines et al. (2007) reported
a suppressor of Pc94 being co-introduced from A. strigosa CI6954SP that segregated from it in backcross
derivatives. This suppressor also inhibited Pc62 but
differed from the Pc38-associated suppressor in other
Pc-gene specific suppression (Rines et al. 2008).
Apparent general species-specific suppression was
reported by Rines et al. (2007) where excellent crown
rust resistance in A. murphyi P12 was suppressed in
crosses and backcross derivatives of A. murphyi P12
A. sativa “Ogle.” A similar lack of expression of the A.
murphyi resistances in crosses to five other susceptible
cultivars indicated a general suppression by A. sativa
(Rines et al. 2008). A lack of resistance expression
was also found in hybridizations to A. sativa of stemrust-resistant A. strigosa PI258731 (H. Rines unpublished) and BYDV-resistant A. strigosa (Ladizinsky
2000).
3.5.2.4 Use of Molecular Markers
Although genes for many traits, particularly disease
resistance, have successfully been introgressed from
wild species into cultivated oat by backcrossing with
selection for the trait at each generation, the process
3 Avena
could now become much more efficient (efficacious) if
one were able to use molecular markers to facilitate
the transfer. Markers could be used to both identify the
gene of interest, being either tightly associated with
the gene or a part of it, and to select for maximum
recovery of the recipient cultivated oat parental
genome. Linked molecular markers have been found
for several introduced genes (as summarized in Rines
et al. 2006), but the identification has usually occurred
only post-introgression for use in further transfer to
other breeding lines. Whereas tightly linked or genespecific markers are valued for selection for the introduced trait, also of value are markers identified in the
surrounding region of the donor genome segment.
Post-introgression selection against such markers can
allow recovery of recombinants with smaller alien
segments lacking possible deleterious genes linked to
the gene of interest. For example, powdery mildew
resistance and stem rust resistance have been introduced into stably transmitting breeding lines, but negative agronomic effects were associated with them
(Brown 1985; Valentine et al. 1994), presumably due
to linked deleterious genes from A. barbata. The effective transfer of the many possible quantitative multigenic traits identified in wild Avena species will
require marker use to identify and track QTLs governing these traits. Also, selection for maximal recovery
of the desired cultivar background in any transfer
effort will require a large number of well-distributed
markers. Thus, the capability to capture and utilize all
the potential in wild oat species for cultivated oat
improvement depends on the development of cheap,
high-throughput markers allowing ready whole genome scans and well characterized molecular linkage
maps at all ploidy levels. Many of the trait-associated
markers identified to date in oat have been difficult
or expensive to assay and with limited polymorphisms
in possible recipients.
3.6 Avena as Weeds and Invasive
Species
Some oat species are weeds infesting cereal crops
(see Sect. 3.1.1.2). Among the diploid species, this is
A. longiglumis, represented by populations of tall,
vigorous plants (up to 2 m tall) weeding crops on
fertile, well moistened sandy soils, and A. atlantica.
Both species weed cereal crops in Morocco (Leggett
et al. 1992). Some other diploid species occur as
ruderal weeds only along the roads or around human
dwellings. On the Ethiopian plateau, the tetraploid
A. vaviloviana is a common weed in wheat and barley
fields, reaching up to 2,200–2,800 m (Ladizinsky
1975). A large population of A. magna (upto 2 m
tall) has been found in Morocco on alluvial soils as a
weed of cereal crops (Leggett et al. 1992). Aggressive
nature of this species has been later confirmed by
other researchers (Saidi and Ladizinsky 2005).
Among all tetraploid species, A. barbata is the most
noxious weed that grows in all Mediterranean
countries. It invades fields of all agricultural crops,
and in the east, its natural range stretches through
Asia Minor, Iraq, and Iran to the Himalayas. It should
be noted that according to the opinion of Malzev
(1930), in the early twentieth century, this species
was entirely wild and did not weed agricultural fields.
The hexaploid species A. sterilis, A. ludoviciana, and
A. fatua are noxious weeds, especially A. fatua, against
which herbicides are being developed. These invasive
species infest vast territories in the basins of the Mediterranean, Black and Caspian seas, and extends through
the Southwest Asia to the easternmost point of the
Asian continent, occupying all agricultural regions.
It should be noted that in the American continent,
south of Africa, Japan, Australia, and countries of
Oceania, A. barbata, A. sterilis, A. ludoviciana, and
A. fatua are noxious adventitious weeds (Malzev
1930; Whalley and Burfitt 1972; Yamaguchi 1976;
Rines et al. 1980; Dillenburg 1984).
Gene flow via pollen dispersal may occur within
the oat crop-wild-weedy complex, which consists of
domesticated oat and its two fully interfertile hexaploid wild relatives A. sterilis and A. fatua. There is
evidence of hybridization between the crop and the
wild species under natural conditions. Although the
levels of outcrossing are usually low, the potential for
gene flow and introgression into wild oats is substantial because of their widespread occurrence.
Thus, the cultivation of transgenic cultivars of oats
and other cereals in future may lead to the transformation of these noxious weeds into super-weeds due to
gene flow from transgenic crops.
I.G. Loskutov and H.W. Rines
3.7 Recommendations for Future
Actions
The international community faces the task of raising
funds and designing programs of safeguarding other
oat wild species: A. clauda (in Greece, Bulgaria,
Turkey, Algeria and Morocco), A. pilosa (Greece,
Turkey, Algeria and Morocco), A. ventricosa (on
Cyprus and in Algeria), A. bruhnsiana (in Azerbaijan),
A. damascene (Syria and Morocco), A. prostrata
(Spain and Morocco), A. atlantica (Morocco), A. agadiriana (Morocco) and A. macrostahya (in Algeria).
Being a unique component of the Earth’s biodiversity,
each of these species contains genetic information that
can be used in practical oat breeding (see Sect. 3.2.1).
3.8 Conclusions
There is considerable interest in extending the range of
cultivated oat through the incorporation of genes from
the wild oat species. A number of considered wild
species are reflected in a wide range of botanic, ecological, and genetic diversity. The results of presented
researches of wild Avena species made it possible
to display intraspecific diversity on all the characters
involved. Numerous researches in this direction and
practical results of oat breeding have evidenced that
utilization of wild species is the most promising trend
of oat breeding, capable of broadening genetic base,
and reducing genetic erosion of this crop.
Acknowledgments Igor G. Loskutov is grateful to Ekatherina
D. Badaeva (Engelhardt Institute of Molecular Biology,
Moscow, Russia), Alexander V. Rodionov (Komarov Botanical
Institute, St. Petersburg, Russia), Irina N. Anisimova (Vavilov
Institute of Plant industry, St. Petetrsburg, Russia), and
Ronald L. Phillips (Department of Agronomy and Plant Genetics, Microbial and Plant Genomics Institute, University of
Minnesota, St. Paul, USA) for critical reading of thе manuscript
and making valuable suggestions and wish to extend thanks to
translator of VIR Mr. Sergei V. Shuvalov.
References
AU23
Aase HC, Powers R (1926) Chromosome numbers in crop
plants. Am J Bot 13:367–372
Abbo S, Lev-Yadun S, Ladizinsky G (2001) Tracing the wild
genetic stocks of crop plants. Genome 44:309–310
Alekperov UK (1982) Anti-mutagenez and conservation of
genetic resources. Priroda 12:24–28
Alekperov UK, Sinitsina ED (1982) Genetic evaluation of resistance of species genus Avena. Dokl AN Azerbajan SSR
38(1):55–57
Alexander DE (1975) The identification of high-quality protein
variants and their use in crop plant improvement. In: Frankel
OH, Hawkes JG (eds) Crop genetic resources for today
and tomorrow. Cambridge University Press, London, UK,
pp 223–230
Alicchio R, Aranci L, Conte L (1995) Restriction fragment
length polymorphism-based phylogenetic analysis of Avena
L. Genome 38:1279–1284
Allard RW (1997) Genetic basis of the evolution of adaptedness in plants. In: Tigerstedt PMA (ed) Adaptation in plant
breeding. Kluwer Academic, Amsterdam, Netherland,
pp 1–11
Arias J, Frey KJ (1973) Selection for seed set crosses of Avena
sativa L. A. abyssinica Hochst. Euphytica 22:413–422
Aujas C, Darmency H (1983) Genetic variability in flowering
time within a population of Avena fatua. Aspects Appl Biol
4:117–123
Aujas C, Darmency H (1984) Le concept d’espece chez les
folles avoines: Avena fatua L. et A. sterilis L. Comptes
rendu du 7 eme colloque international sur l’ecologie, la
boil et la systematique des mauvaises herbes 1:219–227
Aung T, Thomas H (1978) The structure and breeding behaviour
of a translocation involving the transfer of mildew resistance
from Avena barbata Pott. into the cultivated oat. Euphytica
27:731–739
Aung T, Thomas H, Jones IT (1977) The transfer of the gene for
mildew resistance from Avena barbata (4x) into the
cultivated oat A. sativa by an induced translocation. Euphytica 26:623–632
Aung T, Chong J, Leggett JM (1996) The transfer of crown rust
resistance gene Pc94 from a wild diploid to cultivated hexaploid oat. In: Proceedings of the 9th European and Mediterranean Cereal Rusts and Powdery Mildews Conference, 2–6
Sept 1996, Lunteren, The Netherlands, p 3
Avdulov NP (1931) Karyosystematic research of cereals family.
Works of Applied Botany and Plant Breeding. Supplement
No. 44, Leningrad
Axtell JD (1981) Breeding for improvement nutritional quality.
In: Frey KJ (ed) Plant breeding II. Iowa State University,
Ames, Iowa, USA, pp 365–432
Bacon RK (1991) Registration of ‘Ozark’ oat. Crop Sci
31:1383–1384
Badaeva ED, Loskutov IG, Shelukhina OYu, Pukhalsky VA
(2005) Cytogenetic analysis of diploid species of Avena L.
containing As genome. Russ J Genet 41:1718–1724
Balansa B (1854) Bull de la Soc Bot de Fr 1:14
Balansa B, Durieu de Maisonneuve MC (1854) Bull de la Soc
Bot de Fr 1:318
Baum BR (1969) Pedigrees and other basis data of cultivars
oats. In: World wide material that is needed for identification
and registration. Research Branch, Canada Department of
Agriculture, Ottawa
Baum BR (1971) Avena occidentalis, a hitherto overlooked
species of oats. Can J Bot 49:1055–1057
Baum BR (1972) Avena septentrionalis, and the semispecies
concept. Can J Bot 50:2063–2066
3 Avena
Baum BR (1974) Classification of the oat species (Avena, Poaceae) using various taximetric methods and an informationtheoretic model. Can J Bot 52:2241–2262
Baum BR (1977) Oats: wild and cultivated. A monograph of the
genus Avena L. (Poaceae). Monograph No. 14. Research
Branch, Canada Department of Agriculture, Ottawa
Baum BR, Fedak G (1985a) Avena atlantica, a new diploid
species of the oat genus from Morocco. Can J Bot 63:
1057–1060
Baum BR, Fedak G (1985b) A new tetraploid species of Avena
discovered in Morocco. Can J Bot 63:1379–1385
Baum BR, Rajhathy T (1976) A study of Avena macrostachya.
Can J Bot 54:2434–2439
Baum BR, Fleischmann G, Martens JW, Rajhathy T, Thomas H
(1972a) Notes on the habitat and distribution of Avena species in the Mediterranean and Middle East. Can J Bot
50:1385–1397
Baum BR, Rajhathy T, Fleischmann G, Martens JW, Thomas H
(1972b) Wild oat gene pool: a collection maintained by the
Canada Department of Agriculture. Publication No: 1475,
Canada Department of Agriculture, Ottawa
Baum BR, Rajhathy T, Sampson DR (1973) An important new
diploid Avena species discovered on the Canary Islands. Can
J Bot 51:759–762
Baum BR, Rajhathy T, Martens JW, Thomas H (1975) Wild oat
gene pool, edn 2. Publication No: 1475. Canada Department
of Agriculture, Ottawa
Beavis WD, Frey KJ (1987) Expression of nuclear-cytoplasmic
interactions and heterosis in quantitative traits of oats (Avena
spp.). Euphytica 36:877–886
Beer SC, Goffreda J, Phillips TD, Murphy JP, Sorrels ME
(1993) Assessment of genetic variation in Avena sterilis
using morphological traits, isozymes and RFLPs. Crop Sci
33:1386–1393
Bloethe-Helsel D, Frey KJ (1978) Grain yield variations in oats
associated with differences in leaf area duration among oat
lines. Crop Sci 18:765–769
Bor NL (1968) The flora of Iraq. In: The Gramineae, vol 9.
Ministry of Agriculture, Baghdad
Branson CV, Frey KJ (1989a) Recurrent selection for groat oil
content in oat. Crop Sci 29:1382–1387
Branson CV, Frey KJ (1989b) Correlated response to recurrent selection for groat-oil content in oats. Euphytica 43:
21–28
Brezhnev DD, Korovina ON (1981) Wild relatives of cultivated
plants of Flora of the USSR. Kolos, Moscow
Briggle LW, Smith RT, Pomeranz Y, Robbins GS (1975) Protein concentration and amino acid composition of Avena
sterilis L. groats. Crop Sci 15:547–549
Brinkman MA, Frey KJ (1977) Growth analysis of isolinerecurrent parent grain yield differences in oats. Crop Sci
17:426–430
Brodny U, Briggle LW, Wahl I (1976) Reaction of U.S. crown
rust resistant oat selections and Israeli Avena sterilis selections to Puccinia coronata var. Avenae. Plant Dis Rep
60:902–906
Brown PD (1985) The transfer of oat stem rust resistance gene
Pg-16 from tetraploid Avena barbata Pott. to hexaploid
Avena sativa L. Dissert Abstr Int B Sci Eng 45:2036B
Brown CM, Kolb F (1989a) Registration of ‘Don’ oat. Crop Sci
29:1572–1573
Brown CM, Kolb F (1989b) Registration of ‘Hazel’ oat. Crop
Sci 29:1573
Brown CM, Shands HL (1954) Behavior of the interspecific
hybrid and amphiploid of Avena abyssinica A. strigosa.
Agron J 46:557–559
Brown PD, Duguid SD, Haber S, Chong J, Harder DE, Menzies
J, Noll JS, McKenzie RIH (2001) AC Assiniboia oat. Can J
Plant Sci 81:77–79
Browning JA, Frey KJ (1969) Multiline cultivars as a means of
disease control. Annu Rev Phytopathol 7:355–382
Browning JA, Frey KJ (1972) Inheritance of groat-protein in
interspecific oat crosses. Can J Plant Sci 52:203–207
Burdon JJ, Muller WJ (1987) Measuring the cost of resistance
to Puccinia coronata CDA in Avena fatua. J Appl Ecol
24:191–200
Burdon JJ, Oates JD, Marshall DR (1983) Interactions between
Avena and Puccinia species. I. The wild hosts: Avena barbata Pott ex Link, A. fatua L. and A. ludoviciana Durieu.
J Appl Ecol 20:571–584
Burdon JJ, Marshall DR, Oates JD (1992) Interaction between
wild and cultivated oats in Australia. In: Proceedings of the
4th international oat conference, vol 2. 19–23 Oct 1992,
Adelaide, SA, Australia, pp 82–87
Burrows VD (1970) Yield and disease-escape potential of fall-sown
oats possessing seed dormancy. Can J Plant Sci 50:371–378
Burrows VD (1986) Breeding oats for food and feed: conventional and new techniques and materials. In: Webster FH
(ed) Oats: chemistry and technology. American Association
of Cereal Chemists, St. Paul, MN, USA, pp 13–46
Butler-Stoney TR, Valentine J (1991) Exploitation of the
genetic potential of oats for use in feed and human nutrition.
HGCA-Project-Report 32, London, UK
Cadahia E, Garcia-Baudin JM (1978) Differenciacion de la
Avena sterilis L. por electroforesis de proteinas de grano.
Weeds and herbicides in the Mediterranean Basin. In: Proceedings of the mediterranean herbicide symposium,
Madrid, Spain, vol 1, pp 60–67
Campbell AR, Frey KJ (1972) Association between groat-protein percentage and certain plant and seed traits in interspecific oat crosses. Euphytica 21:352–362
Campbell AR, Frey KJ (1974) Inheritance of straw-protein
content and its association with other traits in interspecific
oat crosses. Euphytica 23:369–377
Carrigan LL, Frey KJ (1980) Root volumes of Avena species.
Crop Sci 20:407–408
Carson ML (2008) Virulence frequencies in oat crown rust in
the United States from 2001 through 2005. Plant Dis
92:379–384
Chew BH, Cook R, Thomas H (1981) Investigations on resistance of oats to Heterodera avenae: location of resistance
genes. Euphytica 30:669–673
Cho KC, White PJ (1993) Enzymatic analysis of beta-glucan
content in different oat genotypes. Cereal Chem 70:
539–542
Chong J, Aung T (1996) Interaction of the crown rust resistance
gene Pc94 with several Pc genes. In: Kema GHJ, Niks RE,
Daamen RA (ed) Proceedings of the 9th European and
Mediterranean cereal rusts and powdery mildews conference, 2–6 Sept 1996, Lunteren, The Netherlands. European
and Mediterranean Cereal Rust Foundation, Wageningen,
The Netherlands, pp 172–175
I.G. Loskutov and H.W. Rines
Chong J, Seaman WL (1991) Distribution and virulence of
Puccinia coronata in Canada in 1990. Can J Plant Pathol
13:365–370
Chong J, Leonard KJ, Salmeron JJ (2000) A North American
system of nomenclature for Puccinia coronata F. sp. avenae.
Plant Dis 84:580–585
Chong J, Reimer E, Somers D, Aung T, Penner GA (2004)
Development of sequence-characterized amplified region
(SCAR) markers for resistance gene Pc94 to crown rust in
oat. Can J Plant Pathol 26:89–96
Chong J, Gruenke J, Dueck R, Mayert W, Woods S (2008)
Virulence of oat crown rust [Puccinia coronata f. sp. avenae] in Canada during 2002–2006. Can J Plant Pathol
30:115–123
Choube RN, Gupta SK, Premachandran MN (1985) Utilization
of wild Avena species for gene introgression. Oat Newsl
36:22–23
Clamot G (1969) L’amelioration de la resitance de l’avoine
l’oidium. Etudes preliminares Bull Rech Agron Gembloux
1:134–137
Clamot G (1984) Prospects for improving the grain protein
content of oats by intra- and interspecific hybridization.
Vor Pflanzenzucht 6:224–238
Clark RV, Zillinsky FJ (1960) Varietal reaction of oats to the
Septoria disease under field and green house conditions. Can
Plant Dis Surv 40:72–91
Clifford BC (1995) Diseases, pests and disorders of oats. In:
Welch RW (ed) The oat crop: production and utilization.
Chapman & Hall, London, UK, pp 252–278
Coffman FA (1961) Oat and oat improvement. American Society of Agronomy, Madison, WI, USA
Coffman FA, Stevens H, Stanton TR (1970) Culture of oats in
the Western States. US Department of Agriculture, Texas,
USA, p 2134
Comeau A (1982) Geographic distribution of resistance to barley yellow dwarf virus in Avena sterilis. Can J Plant Pathol
4:147–151
Comeau A (1984) Barley Yellow Dwarf Virus resistance in the
genus Avena. Euphytica 33:49–55
Comeau A (1988) Tolerance of oats to barley yellow dwarf.
In: Proceedings of the 3rd InterntaionalOat Conference, 4–8
July 1988, Lund, Sweden, pp 279–286
Cook R (1974) Nature and inheritance of nematode resistance in
cereals. J Nematol 6:165–174
Cosson ME (1854) Classification desespeces du genre Avena du
groupe de L’Avena sativa. Bull Soc Bot France 1:11–18
Cosson ME, Durie de Maisonneuve MC (1855) Sur quelques
especes nouvelles d’Algerie. Bull Soc Bot France 2:
364–368
Cosson ME, Durieu de Maisonneuve MC (1854) Notes sur quelques graminees d’Algerie. Bull Soc Bot France 1:313–319
Costa JC (1988) Types morphologiques des folles avoines au
Portugal. VIIIe Colloque International sur la Biologie,
l’Ecologie et la Systematique des Mauvaises Herbes. vol 2,
pp 315–323
Cotten J, Hayes JD (1972) Genetic studies of resistance to the
cereal cyst nematode (Heterodera avenae) in oats (Avena
spp.). Euphytica 21:538–542
Cox DJ, Frey KJ (1984a) Improving cultivated oats (Avena
sativa L.) with alleles for vegetative growth index from
A. sterilis L. Theor Appl Genet 68:239–245
Cox DJ, Frey KJ (1984b) Combining ability and the selection of
parents for interspecific oat matings. Crop Sci 24:963–967
Cox TS, Frey KJ (1985) Complementarity of genes for high
groat-protein percentage from Avena sativa L. and A. sterilis
L. Crop Sci 25:106–109
Craig IL, Murray BE, Rajhathy T (1972) Leaf esterase isozymes
in Avena and their relationship to the genomes. Can J Genet
Cytol 14:581–589
Craig IL, Murray BE, Rajhathy T (1974) Avena canariensis:
Morphological and electrophoretic polymorphism and relationship to the A. magna-A. murphyi complex and A. sterilis.
Can J Genet Cytol 16:677–689
Darmency H, Aujas C (1986) Polymorphism for vernalization
requirement in a population of Avena fatua. Can J Bot
64:730–733
Durieu de Maisonneuve MC (1845) Duch Rev Bot 1:360
Dielz SM (1928) Inheritance of resistance in oats to Puccinia
graminis avenae. J Agric Res 37:1–23
Dillenburg CR (1984) Identificacao das especies do genero
Avena (Gramineae) coletadas no estado do Rio Grande do
Sul (Brasil). Anuario Tecnico Instituto Pesquisas Zootecnicas, Francisco Osorio 11:65–102
Dinoor A, Wahl I (1963) Reaction of non-cultivated oats from
Israel to Canada races of crown rust. Can J Plant Sci
43:263–270
Drossou A, Katsiotis A, Leggett JM, Loukas M, Tsakas S (2004)
Genome and species relationships in genus Avena based on
RAPD and AFLP molecular markers. Theor Appl Genet
109:48–54
Duguid SD, Brown PD, Chong J, Harder DE, Haber S, Menzies
J, Nell JS (2001) AC medallion oat. Can J Plant Sci 81:81–83
Dyck PL, Zillinsky FL (1963) Inheritance of crown rust resistance transferred from diploid to hexaploid oats. Can J Genet
Cytol 5:398–407
Eagles HA, Haslemore RM, Stewart CA (1978) Nitrogen utilisation in Libyan strains of Avena sterilis L. with high groat
protein and high straw nitrogen content. N Z J Agric Res
21:65–72
ECPGR (2008) A strategic framework for the implementation of
European genebank integrated system (AEGIS), Discussion
paper. ECPGR, Bioversity International, Rome, Italy
Elliott AL, Thro AM, Frey KJ (1985) Inheritance of groat-oil
content and several other traits in inter- and intra-specific oat
matings. Iowa State Univ Res 60:13–24
Emme EK (1932) Karyosystematic research of oat of section
Euavena Griseb. Works Appl Bot Plant Breed Seria II 1:
147–168
Emme EK (1938) Evolution cultivated and wild oat. Bot J
7:91–122
Ephrat J (1962) Etude sur la comportement thermophasique de
l’avoine (Avena ssp.) en Israel. Bull Econ Nat Super Agron
4:89–95
Fabijanski S, Fedak G, Armstrong K, Altosaar I (1990) A
repeated sequence probe for the C genome in Avena (oats).
Theor Appl Genet 79:1–7
Fawcett JA, Frey KJ (1982) Nitrogen harvest index variation in
Avena sativa and A. sterilis. Proc Iowa Acad Sci 89:155–159
Fetch TG, Jin Y (2007) Letter code system of nomenclature for
Puccinia graminis f.sp. avenae. Plant Dis 91:763–766
Fleischman G, Baker RJ (1971) Oat crown rust race differentation: replacement of the standard differential varieties with a
3 Avena
new set of single resistance gene lines derived from Avena
sterilis. Can J Bot 49:1433–1437
Fleischmann G, McKenzie RIH (1968) Inheritance of crown
rust resistance in Avena sterilis. Crop Sci 8:710–713
Fleischmann G, McKenzie RIH, Shipton WA (1971a) Inheritance of crown rust resistance in Avena sterilis L. from
Israel. Crop Sci 11:451–453
Fleischmann G, McKenzie RIH, Shipton WA (1971b) Inheritance of crown rust resistance genes in Avena sterilis collections from Israel, Portugal, and Tunisia. Can J Genet Cytol
13:251–255
Forsberg RA (1990) The use of monosomic alien substitution
lines in interploidy gene transfer in Avena. Bulg J Biotechnol
4:27–30
Forsberg RA, Shands HL (1969a) Breeding behavior of two
Avena abyssinica A. strigosa amphiploids. Crop Sci
9:64–67
Forsberg RA, Shands HL (1969b) Breeding behavior of 6x
amphiploid A. strigosa F1 hybrids. Crop Sci 9:67–69
Forsberg RA, Shands HL (1989) 5: Oat breeding. In: Janick J
(ed) Plant breeding reviews, vol 6. Timber, Oregon, OR,
USA, pp 167–207
Frey KJ (1975) Inheritability of groat-protein percentage of
hexaploid oats. Crop Sci 15:277–279
Frey KJ (ed) (1981) Plant breeding II. Iowa State University,
Ames, Iowa, USA
Frey KJ (1983) Genes from wild relatives for improving plants.
Crop Improv Res 1–20
Frey KJ (1985) Genetic resources and their use in oats breeding.
In: Proceedings of the 2nd international oats conference,
15–18 July 1985, Aberystwyth, UK, pp 7–15
Frey KJ (1988) Growth rate of oats. In: Proceedings of the 3rd
international oats conference, 4–8 July 1988, Lund, Sweden,
pp 330–339
Frey KJ (1991) Genetic resources of oats. In: Use of plant
introductions in cultivar development. CSSA Special Publication, Part 1, No 17, Madison, WI, USA, pp 15–24
Frey KJ (1992) Oat improvement with genes from Avena species. In: Barr AR, Medd RW (eds) Proceedings of the 4th
international oat conference, vol 2: Wild oats in agriculture.
19–23 Oct 1992, Adelaide, SA, Australia, pp 61–64
Frey KJ (1994) Remaking a crop gene pool: the case history of
Avena. Proceedings of SABRAO 7th international congress
and WSAA symposium, Academia Sinica, vol 1, Special
Publication, Taichung District Agricultural Improvement
Station 35:1–14
Frey KJ, Browning JA (1971) Association between genetic
factors for crown rust resistance and yield in oats. Crop Sci
11:757–760
Frey KJ, Holland JB (1999) Nine cycles of recurrent selection for increased groat-oil content in oat. Crop Sci 39:
1636–1641
Frey KJ, Hammond EG, Lawrence PK (1975a) Inheritance of oil
percentage in interspecific crosses of hexaploid oats. Crop
Sci 15:94–95
Frey KJ, McCarty T, Rosielle A (1975b) Straw-protein percentages in Avena sterilis L. Crop Sci 15:716–718
Frey KJ, Cox TS, Rodgers DM, Bramel-Cox P (1984) Increasing cereal yields with genes from wild and weedy species.
In: Genetics: new frontiers. 15th international congress on
genetics, vol 4: Applied genetics, pp 51–68
Frey KJ, Browning JA, Simons MD (1985) Registration of
Multiline E76 and Multiline E77 oats. Crop Sci 25:1125
Frey KJ, Michel LJ, Murphy JP, Browning JA (1986) Registration of Webster isolines. Crop Sci 26:374–375
Frey KJ, Simons MD, Michel LJ, Murphy JP, Browning JA
(1988) Registration of Webster oat isolines as parental
lines. Crop Sci 28:386–387
Frison E, Koenig J, Schittenhelm S (1993) Report of a working
group on Avena. 4th Meet, Godolo, Hungary, 26–28 May
1993, ECP/GR. International Board for Plant Genetics
Resources, Rome, Italy
Fu Y-B, Williams DJ (2008) AFLP variation in 25 Avena
species. Theor Appl Genet 117:333–342
Fu Y-B, Chong J, Fetch T, Wang M-L (2007) Microsatellite
variation in Avena sterilis oat germplasm. Theor Appl Genet
114:1029–1038
Garcia P, Vences FJ, Perez de la Vega M, Allard RW (1989)
Allelic and genotypic composition of ancestral Spanish and
colonial Californian gene pools of Avena barbata: evolutionary implications. Genetics 122:687–694
Garcia-Baudin JM, Salto T, Aguirre R (1978) Variabilidad de la
Avena sterilis L. en la zona interior de la peninsula Iberica.
Anales Instituto Nacional Investigaciones Agrarias Proteccion Vegetal 8:149–158
Garcia-Baudin JM, Salto T, Aguirre R (1981) Differentes types
morphologiques chez Avena sterilis L. Fragm Herb Jugosl
10(1):57–71
Gavrilova O, Gagkaeva T, Burkin A, Kononenko G, Loskutov I
(2008) Susceptibility of oat germplasm to Fusarium infection and mycotoxin accumulation in grains. In: Proceedings
of the 8th international oat conference, 27 June–2 July 2008,
Minneapolis, MN, USA, Poster V-2a. http://wheat.pw.usda.
gov/GG2/Avena/event/IOC2008/IOCprogram.html
Germeier CU (2008) Global strategy for the ex situ conservation
for oats (Avena spp.). http://www.croptrust.org/documents/
web/Oat-Strategy-DRAFT-07April08.pdf
Goffreda JC, Burnquist WB, Beer SC, Tanksley SD, Sorrells
ME (1992) Application of molecular markers to assess
genetic relationships among accessions of wild oat, Avena
sterilis. Theor Appl Genet 85:146–151
Gold Steinberg J, Mitchell Fetch J, Fetch TG (2005) Evaluation
of Avena spp. collections for resistance to oat stem rust. Plant
Dis 89:521–525
Griffiths NAR (1984) Studies of chromosome manipulation in
Avena. PhD Thesis, University of Wales, Aberystwyth
Griffiths DJ, Rowlands G, Peregrine WTH (1959) Cytogenetic
relationships of certain artifical and natural species of Avena.
J Agric Sci 52:678–683
Grisebach AHR (1844) Spicilegium florae rumelicae et bithynicae, vol II. Friedrich Vieweg und Sohn, Brunsvigae, p 452
Grossheim AA (1967) Flora of Caucasus, vol 2. Nauka,
Moscow–Leningrad
Gruner LF (1867) Bull Soc Imp Naturalistes Moscou. xli. II. 458
Guarino L, Chadja H, Mokkadem A (1991) Collection of Avena
macrostachya Bal. ex Coss. et Dur. (Poaceae) germplasm in
Algeria. Econ Bot 45(4):460–466
Guillemenet R (1971) Wild oats in Vienne. Phytoma 232:24–27
Guma I-R, Perez de la Vega M, Pedro G (2006) Isozyme
variation and genetic structure of populations of Avena
barbata from Argentina. Genet Resour Crop Evol 53:
587–601
I.G. Loskutov and H.W. Rines
Gupta SC, Cox DJ, Frey KJ (1986a) Association of two measures of vegetative growth rate with other traits in inter and
intraspecific matings of oats. Theor Appl Genet 72:756–760
Gupta SC, Frey KJ, Cox DJ (1986b) Changes in several traits of
oats caused by selection for vegetative growth rate. Plant
Breed 97:222–226
Gupta SC, Frey KJ, Skrdla RK (1987) Selection for grain yield
of oats via vegetative growth rates measured at anthesis and
maturity. Euphytica 36:91–97
Hagberg P (1983) Artkorsningar i havre (Abstr). Nordisk Jordbrugsforskning 65:271
Hagberg P, Mattsson B (1986) Increased variability in oats from
crosses between different species. In: Olsson G (ed) Svalof
1886–1986: Research and results in plant breeding. LTs
forlag, Stockholm, Sweden, pp 121–127
Hammer K, Teklu Y (2008) Plant genetic resources: selected
issues from genetic erosion to genetic engineering. J Agric
Rural Dev Trop Subtrop 109:15–50
Harder DE, McKenzie RIH (1984) Complex additive-type of
resistance to Puccinia coronata in Avena sterilis. Can J Plant
Pathol 6:135–138
Harder DE, McKenzie RIH, Martens JW (1980) Inheritance of
crown rust resistance in three accessions of Avena sterilis.
Can J Genet Cytol 22:27–33
Harder DE, McKenzie RIH, Martens JW (1984) Inheritance of
adult plant resistance to crown rust in an accession of Avena
sterilis. Phytopathology 74:352–353
Harder DE, Chong J, Brown PD, Martens JW (1990) Inheritance
of resistance to Puccinia coronata avenae and P. graminis
avenae in an accession of Avena sterilis from Spain. Genome
33:198–202
Harder DE, Chong J, Brown PD, Sebesta J, Fox S (1992) Wild
oat as a source of disease resistance: history, utilization and
prospects. In: Proceedings of the 4th international oat conference, vol 2, 19–23 Oct 1992, Adelaide, SA, Australia,
vol 2, pp 71–81
Harlan JR (1975) Crop and man. American Agricultural Society,
Madison, WI, USA
Harlan JR, de Wet JMJ (1971) Toward a rational classification
of cultivated plants. Taxon 20:509–517
Haussknecht C (1885) Uber die Abstammung des Saathaber.
Mitteil. d. geogr. Gesellsch. (Thur.), Jena III, pp 231–242
Hayasaki M, Morikawa T, Leggett MJ (2001) Intraspecific variation of 18S-5.8S-26S rDNA sites revealed by FISH and RFLP
in wild oat, Avena agadiriana. Gene Genet Syst 76:9–14
Hayes JD (1970) Arable crop breeding. In: Welsh plant breeding
station jubilee report 1919–1969, pp 45
Herrmann M, Roderick HW (1996) Characterisation of new oat
germplasm for resistance to powdery mildew. Euphytica
89:405–410
Hetzler J, Dambroth M (1990) Erstevaluierung von Winterhafer
(Avena sativa L.). Landbauforschung-Volkenrode 40(4H):
279–283
Heum M, Murphy JP, Phillips TD (1994) A comparison of
RAPD and isozyme analyses for determining the genetic
relationships among Avena sterilis L. accessions. Theor
Appl Genet 87:689–696
Hochstetter CFF (1852) Schimp. Inter. Abyss. Sectio II. In:
Plantae Abyssineae, Ed. II
Hoffman DL (1996) Inheritance and linkage relationships of
morphological and isozyme loci in the A-genome diploid
oat. In: Proceedings of the 5th international oat conference,
vol 2, 30 July–6 Aug 1996, Saskatoon, Sask., Canada,
pp 330–332
Hoffman DL, Chong J, Jackson EW, Obert DE (2006) Characterization and mapping of a crown rust resistance gene
complex (Pc58) in TAM O-301. Crop Sci 46:2630–2635
Holden JHW (1966) Species relationships in the Avenae. Chromosoma 20(I):75–124
Holden JHW (1969) Field studies of some wild species of
Avena. Econ Bot 23:339–345
Holden JHW (1979) 28 Oats. Avena spp. (Gramineae – Aveneae). In: Simmonds NW (ed) Evolution of crop plants.
Longman, London, UK, pp 86–90
Holland JB (1997) Oat improvement. In: Kang MS (ed)
Crop improvement for the 21st century. Research Signpost,
Trivandrum, India, pp 57–98
Holland JB, Bjornstad A, Frey KJ, Gullord M, Wesenberg DM
(1996) Recurrent selection for yield stability in a broadbased oat population. In: Proceedings of the 5th international
oat conference, vol 2, 30 July–6 Aug 1996, Saskatoon, Sask.,
Canada, pp 494–496
Holub J (1958) Bemerkungen zur taxonomie der Gattung Helictotrichon Bess. In: Nemec B, Klastersky I et al (eds) Philipp
Maxmilian Opiz und Seine Bedeutung fur die Pflanzentaxonomie. Tschechoslowakischen Akad. der Wissenschaften,
Prag, pp 101–133
Hoppe G, Hoppe HD (1991) Cluster analyses as breeding aid
shown by the example of interspecific hybrids of Avena. A
Zuchtungsforsch 21:183–190
Hoppe HD, Kummer M (1991) New productive hexaploid derivatives after introgression of A. pilosa features. Vor. Pflanzenzuchtg 20:56–61
Hoppe HD, Pohler W (1988) Successful hybridization between
Avena prostrata and A. macrostachya. Cereal Res Commun
16:231–235
Hoppe HD, Pohler W (1989) Hybrids between Avena barbata
and A. macrostachya. Cereal Res Commun 17:129–134
Hoppe HD, Pohler W, Kison HU (1990) Tri-, tetra- und pentaploide Bastarde aus interspezifischen Kreuzungen mit Avena
macrostachya. Biol Zentralblatt 109:499–504
Howarth C, Cowan A, Leggett JM, Valentine J (2000) Using
molecular mapping to access and understanding valuable
traits in wild relatives of oats. In: Proceedings of the 6th
internationl oat conference, 13–16 Nov 2000, Canterbury,
New Zealand, pp 157–159
Huskins CL (1926) Genetical and cytological studies of the
origin of false wild oats. Sci Agric 6:303–313
Huskins CL (1927) On the genetics and cytology of fatuoid or
false wild oat. J Genet 18:315–364
IBPGR (1984) Report of a Working Group on Oat. Menemen,
Turkey, 25–27 Sept 1984. ECP/GR. International Board for
Plant Genetics Resources, Rome, Italy
IBPGR (1986) Report of a Working Group on Avena (Second
Meeting). Braunschweig, Germany, 18–20 Mar 1986. ECP/
GR. International Board for Plant Genetics Resources,
Rome, Italy
IBPGR (1989) Report of a Working Group on Avena (Third
Meeting). Radzikow, Poland, 7–9 Mar 1989. ECP/GR. International Board for Plant Genetics Resources, Rome, Italy
Irigoyen ML, Loarce Y, Linares C, Ferrer E, Leggett M,
Fominaya A (2001) Discrimination of the closely related
3 Avena
A and B genomes in AABB tetraploid species of Avena.
Theor Appl Genet 103:1160–1166
Jain RK, Hasan N (1988) Further studies on the root-knot
nematode Meloidogyne javanica infecting Avena sterilis.
Acta Bot Indica 16:239–241
Jellen EN, Beard J (2000) Geographical distribution of a chromosome 7C and 17 intergenomic translocation in cultivated
oat. Crop Sci 40:256–263
Jellen EN, Ladizinsky G (2000) Giemsa C-banding in Avena
insularis Ladizinsky. Genet Resour Crop Evol 47(227):230
Jellen EN, Leggett JM (2006) Cytogenetic manipulation in oat
improvement. In: Singh RJ, Jauhar PP (eds) Genetic
resources, chromosome engineering, and crop improvement.
Chap. 2 Cereals. CRC, Boca Raton, pp 199–231
Jellen EN, Phillips RL, Rines HW (1994) Chromosomal localization and polymorphisms of ribosomal DNA in oat (Avena
spp.). Genome 37:23–32
Jellen EN, Phillips RL, Rines HW, Rooney WL (1995) Molecular genetic identification of Avena chromosomes related to
the group 1 chromosomes of the Triticeae. Genome
38:185–189
Jessen CFW (1863) Deutschland Graser und Getreidearten.
Leipzig 214–218
Johnson LDR, Rothman PG (1986) Resistance to stem rust in
Avena fatua L. (Abstr). Phytopathology 76:1147
Jones ET, Griffiths DJ (1952) Varietal resistance and susceptibility of oats to powdery mildew (Erysiphe graminis). Br
Mycol Soc Trans 35:71–80
Jones IT, O’Reilly AM, Davies IJER (1984) Cereal breeding.
Durable resistance to powdery mildew in oats. In: Annual
report, 1983. Oats. Welsh Plant Breeding Stationn, pp 93–94
Kahler AL, Allard RW, Krzakowa M, Wehrhahn CF, Nevo E
(1980) Associations between isozyme phenotypes and environment in the slender wild oat (Avena barbata) in Israel.
Theor Appl Genet 56:31–47
Kanan G, Jaradat AA (1996) Wild oats in Jordan. In: Proceedings of the 5th international oat conference, vol 2. 30 July–6
Aug 1996, Saskatoon, Sask., Canada, pp 185–187
Karow RS (1984) Studies on the inheritance of fatty acid composition and the enzyme lipoxygenase in cultivated oat
(Avena sativa L.) and on the inheritance of crown rust
resistance in a derived-tetraploid natural tetraploid oat
cross (Abstr). Dissert Abstr Int Sci Eng 44(9):2623B–2624B
Karow RS, McNamara KR, Forsberg RA (1987) Crown rust
resistance in progeny from a derived tetraploid natural
tetraploid cross in Avena. Genome 29:206–208
Katsiotis A, Schmidt T, Heslop-Harrison JS (1996) Chromosomal and genomic organization of Ty1-copia-like retrotransposon sequences in the genus Avena. Genome
39:410–417
Katsiotis A, Hagidimitriou M, Heslop-Harrison JS (1997) The
close relationship between the A and B genomes in Avena L.
(Poaceae) determined by molecular cytogenetic analysis of
total genomic, tandemly and dispersed repetitive DNA
sequences. Ann Bot 79:103–109
Katsiotis A, Loukas M, Heslop-Harrison JS (2000) Repetitive
DNA, genome and species relationships in Avena and Arrhenatherum (Poaceae). Ann Bot 86:1135–1142
Kiehn FA, McKenzie RIH, Harder DE (1976) Inheritance of
resistance to Puccinia coronata avenae and its association
with seed characteristics in four accessions of Avena sterilis.
Can J Genet Cytol 12:230–236
Kihara H (1919) Ueber cytologische Studien bei einigen Getreidearten. Mitteilung II. Chromosomenzahlen und Verwandtschaftsverhaltnisse unetr Avena-Arten. Bot Mag
XXXIII 388:94–97
Kim HB (1974) Inheritance of resistance to Puccinia coronata
var. avenae in sex selections of Avena sterilis. Euphytica
23:174–180
Kliphuis E, Wieffering JH (1972) Chromosome numbers of
some angiosperms from the south of France. Acta Bot Neerlandica 21:598–604
Koch K (1848) Beitrage zu einer Flora des Orientes. Linneaea
21:289–443
Kropac Z, Lhotska M (1971) Avena ludoviciana Dur. and
Bidens frondosus L. – two new species for Romanian Socialist Republic. Preslia 43:249–253
Kuenzel KA, Frey KJ (1985) Protein yield of oats as determined by protein percentage and grain yield. Euphytica
34:21–31
Kuhn F (1972) Oats in the Western Carpathians. Acta Universitatis Agriculturae Brno Facultas Agronomica 20:355–362
Ladizinsky G (1969) New evidence on the origin of hexaploid
oats. Evolution 23:4
Ladizinsky G (1971a) Avena murphyi: a new tetraploid species
of oat from southern Spain. Isr J Bot 20:24–27
Ladizinsky G (1971b) Avena prostrata: a new diploid species of
oat. Isr J Bot 20:297–301
Ladizinsky G (1971c) Biological flora of Israel. 2. Avena L. Isr J
Bot 20:133–151
Ladizinsky G (1971d) Chromosome relationships between tetraploid (2n¼28) Avena murphyi and some diploid, tetraploid
and hexaploid species of oats. Can J Genet Cytol
13:203–209
Ladizinsky G (1973a) The cytogenetic position of Avena
prostrata among the diploid oats. Can J Genet Cytol 15:
443–450
Ladizinsky G (1973b) Genetic control of bivalent pairing in the
Avena strigosa polyploid complex. Chromosoma
42:105–110
Ladizinsky G (1975) Oats in Ethiopia. Econ Bot 29:238–241
Ladizinsky G (1988) Biological species and wild genetic
resources in Avena. In: Proceedings of 3rd international oat
conference, 4–8 July 1988, Lund, Sweden, pp 76–86
Ladizinsky G (1989) Biological species and wild genetic
resources in Avena. IBPGR, Report of a Working Group on
Avena, Radzikow, Poland, pp 19–32
Ladizinsky G (1992) Genetic resources of tetraploid wild oats
and their utilization. In: Proceedings of the 4th international
oat conference, 19–23 Oct 1992, Adelaide, SA, Australia,
pp 65–70
Ladizinsky G (1995) Domestication via hybridization of the
wild tetraploid oats Avena magna and A. murphyi. Theor
Appl Genet 91:639–646
Ladizinsky G (1998) A new species of Avena from Sicily,
possible the tetraploid progenitor of hexaploid oats. Genet
Res Crop Evol 45:263–269
Ladizinsky G (1999) Cytogenetic relationships between Avena
insularis (2n¼28) and both A. strigosa (2n¼14) and A.
murphyi (2n¼28). Genet Resour Crop Evol 46:501–504
I.G. Loskutov and H.W. Rines
Ladizinsky G (2000) A synthetic hexaploid (2n ¼ 42) oat from
the cross of Avena strigosa (2n ¼ 14) and domesticated A.
magna (2n ¼ 28). Euphytica 116:231–235
Ladizinsky G, Fainstein R (1977) Domestication of the proteinrich tetraploid wild oats Avena magna and A. murphyi.
Euphytica 26:221–223
Ladizinsky G, Jellen EN (2003) Cytogenetic affinities between
populations of Avena insularis Ladizinsky from Sicily and
Tunisia. Genet Resour Crop Evol 50:11–15
Ladizinsky G, Johnson L (1972) Seed protein homologies and
the evolution of poliploidy in Avena. Can J Genet Cytol
14:875–888
Ladizinsky G, Zohary D (1968) Genetic relationships between
diploids and tetraploids in series Eubarbatae of Avena. Can
J Genet Cytol 10:68–81
Ladizinsky G, Zohary D (1971) Notes on species delimination
species relationships and poliploidy in Avena L. Euphytica
20:380–395
Lagasca SM (1816) Quae aut novae sunt aut nondum recte
cognoscuntur. Genera et species plantarum, Madrid, p 4
Landry B, Comeau A, Minvielle F, St.-Pierre CA (1984)
Genetic analysis of resistance to barley yellow dwarf virus
in hybrids between Avena sativa ‘Lamar’ and virus-resistant
lines of Avena sterilis. Crop Sci 24:337–340
Lawrence PK, Frey KJ (1975) Backcross variability for grain
yield in oat species crosses (Avena sativa L. A. sterilis L.).
Euphytica 24:77–85
Leggett JM (1980) Chromosome relationships and morphological comparisons between the diploid oats Avena prostrata,
A. canariensis and the tetraploid A. maroccana. Can J Genet
Cytol 22:287–294
Leggett JM (1984) Morphology and metaphase chromosome
pairing in three Avena hybrids. Can J Genet Cytol 26:
361–364
Leggett JM (1985) Interspecific hybrids involving the perennial
oat species Avena macrostachya. Can J Genet Cytol
27:29–32
Leggett JM (1987) Interspecific hybrids involving the recently
described diploid taxon Avena atlantica. Genome 29:
361–364
Leggett JM (1988) Inter- and intra-specific hybrids involving the
tetraploid species Avena agadiriana Baum et Fedak sp. nov.
(2n¼4x¼28). In: Proceedings of the 3rd international oat
conference, 4–8 July 1988, Lund, Sweden, pp 62–67
Leggett JM (1990) A new triploid hybrid between Avena
eriantha and A. macrostachy. Cereal Res Commun
18:97–110
Leggett JM (1992a) The conservation and exploration of wild
oat species. In: Proceedings of the 4th international oat
conference, vol 2. 19–23 Oct 1992, Adelaide, SA, Australia,
pp 57–60
Leggett JM (1992b) A further Avena macrostachya hybrid. In:
Proceedings of the 4th international oat conference, vol 3.
19–23 Oct 1992, Adelaide, SA, Australia, pp 152–153
Leggett JM (1996) Using and conserving Avena genetic
resources. In: Proceedings of the 5th international oat conference, 30 July–6 Aug 1996, Saskatoon, Sask, vol 1.
Canada, pp 128–132
Leggett JM (1997) A revision of genome evolution in hexaploid
Avena? Exp Biol Online: Aberystwyth Cell Genetics Group
Meet
Leggett JM (1998) Chromosome and genomic relationship
between the diploid species Avena strigosa, A. eriantha,
and the tetraploid A. maroccana. Heredity 80:361–367
Leggett JM, Markland GS (1995) The genomic structure of
Avena revealed by GISH. Proc Kew Chrom Conf 4:133–139
Leggett JM, Thomas H (1995) Oat evolution and cytogenetics.
In: Welch RW (ed) The oat crop production and utilization.
Chapman & Hall, London, UK, pp 120–149
Leggett JM, Ladizinsky G, Hagberg P, Obanni M (1992) The
distribution of nine Avena species in Spain and Morocco.
Can J Bot 70:240–244
Leonard K, Martinelli JA (2005) Virulence of oat crown rust in
Brazil and Uruguay. Plant Dis 89:802–808
Leonova S, Shelenga T, Hamberg M, Konarev AV, Loskutov IG,
Carlsson AS (2008) Analysis of oil composition in cultivars
and wild species of oat (Avena sp.). J Agric Food Chem
56:7983–7991
Levitsky GA (1976) Plant Cytology, 1931: selected works.
Nauka, Moscow
Li CD, Rossnagel BG, Scoles GJ (2000) The development of oar
microsatellite markers and their use in identifying relationships among Avena species and oat cultivars. Theor Appl
Genet 101:1259–1268
Li WT, Peng YY, Wei YM, Baum BR, Zheng YL (2009)
Relationships among Avena species as revealed by consensus chloroplast simple sequence repeat (ccSSR) markers.
Genet Resour Crop Evol 56:465–480
Linares C, Gonzalez J, Ferrer E, Fominaya A (1996) The use of
double fluorescence in situ hybridization to physically map
the positions of 5S rRNA genes in relation to the chromosomal location of 18S–5.8S–26S rDNA and a C genomespecific DNA sequence in the genus Avena. Genome
39:535–542
Linneaus C (1762) Species Plantarum, 2nd edn. London, UK
Linneaus С (1753) Species Plantarum. vol 1. A facsimile of the
first edition. London, UK, 1957. 1959
Lipman E, Maggioni L, Knupffer H, Ellis R, Leggett M, Kleijer G,
Faberova I, Le Blanc A (2005) Cereal genetic resources in
Europe. Report on Cereals Network. 1st Meeting, 3–5 July
2003, Yerevan, Armenia. ECP/GR. International Plant
Genetics Resource Institute, Rome, Italy
Litzenberger SC (1949) Inheritance of resistance to specific
races of crown and stem rust to Helminthosporium blight,
and of certain agronomic characters of oats. Iowa Agric Exp
Stn Bull 370:453–496
Loarce Y, Ferrer E, K€
unzel G, Fominaya A (2002) Assignment
of oat linkage groups to microdissected Avena strigosa chromosomes. Theor Appl Genet 104:1011–1016
Lookhart GL, Pomeranz Y (1985) Characterization of oat species by polyacrylamide gel electrophoresis and high performance liquid chromatography of their prolamin proteins.
Cereal Chem 62:162–166
Loon van JC (1974) A cytological investigation of flowering
plants from the Canary Islands. Acta Bot Neerlandica
23:113–124
Loskutov IG (1998) The collection of wild species of CIS as a
source of diversity in agricultural traits. Genet Resour Crop
Evol 45:291–295
Loskutov IG (1999) Vavilov and his institute. A history of the
world collection of plant genetic resources in Russia. IPGRI,
Rome, Italy
3 Avena
AU24
Loskutov IG (2001a) Influence of vernalization and photoperiod
to the vegetation period of wild species of oats (Avena spp.).
Euphytica 117:125–131
Loskutov IG (2001b) Interspecific crosses in Avena L. genera.
Russ J Genet 37:581–590
Loskutov IG (2007) Oat (Avena L.). Distribution, taxonomy,
evolution and breeding value. VIR, St. Peterburg, Russia
Loskutov IG (2008) On evolutionary pathway of Avena species.
Genet Resour Crop Evol 55:211–220
Luby JJ, Stuthman DD (1983) Evaluation of Avena sativa L./
A. fatua L. progenies for agronomic and grain quality characters. Crop Sci 23:1047–1052
Luby JJ, Stuthman DD, Phillips RL (1985) Micronuclei frequency and character coherence in Avena sativa L./A.fatua
L. crosses. Theor Appl Genet 69:367–373
Lupton FGH, Thompson JB (1961) Spring oats. In: Annual
report 1959–1960. PBI Cambridge, UK, pp 235–238
Lyrene PM, Shands HL (1975) Groat protein percentage in
Avena sativa A. sterilis crosses in early generations.
Crop Sci 15:398–400
Maggioni L, Leggett M, Bucken S, Lipman E (1998) Report of
a Working Group on Avena. 5th meeting, Vilnus, Lithuania,
7–9 May 1998. ECP/RG. International Plant Genetic
Resources Institute, Rome, Italy
Maggioni L, Katsiotis A, Kn€
upffer H, Kleijer G (2009) Report
of a Cereals Network. 2nd Meeting, 21–24 Apr 2008, Foça,
Turkey. ECPGR, Biversity International, Rome, Italy
(in press)
Maillet J (1980) Contribution a une etude des varietes d’Avena
fatua et Avena sterilis. Fragm Herb Jugosl 9:61–67
Mal B (1987) Wild genetic resource potential for forage oat
improvement (Abstr). In: 1st Symposium on crop improvement, 23–27 Feb 1987, India, pp 5–6
Malzev AI (1930) Wild and cutivated oats. Section Euavena
Griseb. Works Appl Bot Plant Breed Suppl No: 38. Leningrad, USSR
Mansfeld R (1958) Zur Nomenklatur einiger Nutz- und Kulturpflanzen. Kulturphflanze 6:237–242
Markhand GS, Leggett JM (1996) The genomes of A. lusitanica,
A. hispanica and A. matritensis confirmed using GISH. In:
Proceedings of 5th international oat conference, vol 2. 30
July–6 Aug 1996, Saskatoon, Sask, Canada, pp 347–349
Marshall Bieberstein FA (1819) Avena pilosa. Flora Taur.Cauc. III. Suppl. 84
Marshall DR, Allard RW (1970) Isozyme polymorphisms in
natural populations of Avena fatua and A. barbata. Heredity
25:373–382
Marshall DR, Jain SK (1968) Phenotype plasticity of Avena
fatua and A. barbata. Nature (Lond) 221:276–278
Marshall DR, Jain SK (1970) Seed predation and dormancy in
the population dynamics of Avena fatua and A. barbata.
Ecology 51:886–891
Marshall HG, Shaner GE (1992) Genetic and inheritance in oat.
In: Marshall HG, Sorrells ME (eds) Oat science and technology. Agronomy Monograph No. 33. ASA, CSSA, SSSA,
Madison, WI, USA, pp 509–571
Martens JW, McKenzie RIH (1973) Resistance and virulence in
the Avena: Puccinia coronata host-parasite system in Kenya
and Ethiopia. Can J Bot 51:711–714
Martens JW, McKenzie RIH, Harder DE (1980) Resistance to
Puccinia graminis avenae and P. coronata avenae in the
wild and cultivated Avena populations of Iran, Iraq and
Turkey. Can J Genet Cytol 22:641–649
Martens JW, Rothman PG, McKenzie RIH, Brown PD (1981)
Evidence for complementary gene action conferring resistance to Puccinia graminis avenae in Avena sativa. Can
J Genet Cytol 23:591–595
Martens JW, Brown PD, McKenzie RIH, Harder DE (1983)
Development of resistance to Puccinia graminis avenae in
Avena sativa by mutagen treatment. In: Induced mutations
for disease resistance in crop plants II. IAEA, Vienna,
Austria, pp 105–110
Mattsson B (1988) The development of oat germplasm at Svalov.
In: Mattsson B, Lyhagen L (eds) Proceedings of 3rd international oat conference, 4–8 July 1988, Lund, Sweden, pp 35–38
Maxted N, Ford-Lloyd BV, Hawkes JG (1997) Complementary
conservation strategies. In: Maxted N, Ford-Lloyd BV,
Hawkes JG (eds) Plant genetic conservation: the in situ
approach. Chapman & Hall, London, UK, pp 15–40
McCallum BD, Harder DE, Dunsmore KM (2000) Stem rusts on
wheat, barley, and oat in Canada in 1999. Can J Plant Pathol
22:23–28
McDaniel ME (1974a) Registration of TAM 0-301 oats. Crop
Sci 14:127–128
McDaniel ME (1974b) Registration of TAM 0-312 oats. Crop
Sci 14:128
McFerson JK, Frey KJ (1990) Three selection strategies to
increase protein yield in oats. J Genet Breed 44:56–59
McFerson JK, Frey KJ (1991) Reccurrent selection for protein
yield. Crop Sci 31:1–8
McKenzie RIH, Fleischmann G (1964) The inheritance of
crown rust resistance in selections from two Israeli collections of Avena sterilis. Can J Genet Cytol 6:232–236
McKenzie RIH, Martens JW, Rajhathy T (1970) Inheritance of
oat stem rust resistance in a Tunisian strain of Avena sterilis.
Can J Genet Cytol 12:501–505
McKenzie RIH, Martens JW, Brown PD, Harder DE, Nielsen J,
Boughton GR (1981) Registration of Fidler oats. Crop Sci
21:623
McKenzie RIH, Brown PD, Martens JW, Harder DE, Nielsen J,
Gill CC, Boughton GR (1984) Registration of Dumont oats.
Crop Sci 24:207
McMullen MS (2005) Registration of ‘HiFi’ oat. Crop Sci
45:1664
McMullen MS, Patterson FL (1992) Oat cultivar development in
the U.S.A. and Canada. In: Sorrells ME, Marshall HG (eds)
Oat Science and Technology. Agronomy Monograph No. 33.
ASA, CSSA, SSSA, Madison, WI, USA, pp 573–612
McMullen MS, Phillips RL, Stuthman DD (1982) Meiotic irregularities in Avena sativa L./A. sterilis L. hybrids and breeding implications. Crop Sci 22:890–897
Milach SCK, Rines HW, Phillips RL, Stuthman DD, Morikawa
T (1998) Inheritance of a new dwarfing gene in oat. Crop Sci
38:356–360
Miller SS, Wood PJ, Pietrzak LN, Fulcher RG (1993) Mixed
linkage b-glucan, protein content and kernel weigh in Avena
species. Cereal Chem 70:231–233
Mitrofanov AS, Mitrofanova KS (1972) Oat. Kolos, Moscow,
USSR
Mordvinkina AI (1936) Oat – Avena. Cultivated flora of the
USSR. In: Cereals, vol 2. Rye, Barley, Oat. State Agriculture, Moscow–Leningrad, pp 333–438
I.G. Loskutov and H.W. Rines
Mordvinkina AI (1969a) Resistance species, ecologo-geographical groups and varieties to main diseases. Works Appl Bot
Genet Plant Breed 39(3):233–242
Mordvinkina AI (1969b) Variety resources of oat. Works Appl
Bot Genet Plant Breed 41(1):87–93
Morikawa T (1989) Genetic analysis on dwarfness of wild oats.
Jpn J Genet 64:363–371
Morikawa T (1991) Isozyme and chromosome polymorphisms
of the genus Avena and its geographic distribution in
Morocco. Wheat Inform Serv 72:104–105
Morikawa T (1992) Isozyme and chromosome variations of
the Avena species in the Canary Islands and Morocco. In:
Proceedings of the 4th international oat conference, vol 3.
19–23 Oct 1992, Adelaide, SA, Australia, pp 138–140
Morikawa T (1995) Transfer of mildew resistance from the wild
oat Avena prostrata into the cultivated oat. Bull Univ Osaka
Prefect Ser B Agric Life Sci 47:1–10
Morikawa T, Leggett JM (1990) Isozyme polymorphism in
natural populations of Avena canariensis from the Canary
Islands. Heredity 64:403–411
Morikawa T, Leggett JM (2005) Isozyme polymorphism and
genetic differentiation in natural populations of a new tetraploid species Avena agadiriana, from Morocco. Genet
Resour Crop Evol 52:363–370
Morikawa T, Sumiya M, Kuriyama S (2007) Transfer of new
dwarfing genes from the weed species Avena fatua into
cultivated oat A. byzantine. Plant Breed 126:30–35
Moser HS, Frey KJ (1994) Direct and correlated responses to
three S1-recurrent selection strategies for increasing protein
yield in oat. Euphytica 78:123–132
Murphy JP, Phillips TD (1993) Isozyme variation in cultivated
oat and its progenitor species, Avena sterilis L. Crop Sci
33:1366–1372
Murphy HC, Sadanaga K, Zilinsky FJ, Terrell E, Smith RT
(1968) Avena magna: an important new tetraploid species
in oats. Science 159:103–104
Murray BE, Craig JL, Rajhathy T (1970) A protein electrophoretic study of three amphiploids and eight species in Avena.
Can J Genet Cytol 12:651–655
Musaev SG (1969) About new species of oat for flora of the
USSR. Doklady AN Azerbaijan SSR 25(10):35–40
Musaev SG, Isaev YaM (1971) Brunsa’s oat – endemic species
of Azerbaijan Flora. Doklady AN Azerbaijan SSR 27(5):
64–65
Musaev SG, Nuriev SG, Sadygov IA (1976) New species of
gramineous grasses in Flora of Nakhichevan SSR. Izv AN
Azerbaijan SSR Biol Sci 5:12–15
Nevski S (1934) Conspectus specierum generis Avenae. Schedae ad Herb. Flora Asie med Fusc 21–23
Nielsen J (1978) Frequency and geographical distribution of
resistance to Ustilago in six wild species of Avena. Can J
Plant Sci 58:1099–1101
Nielsen J (1993) Host specificity of Ustilago avenae and
U. hordei on eight species of Avena. Can J Plant Pathol
15:14–16
Nikolaeva AG (1922) Using of cytological method in breeding
and genetics. Nauchnye Izv 4:183–188
Nikoloudakis N, Katsiotis A (2008) The origin of the C-genome
and cytoplasm of Avena polyploids. Theor Appl Genet
117:273–281
Nikoloudakis N, Skaracis G, Katsiotis A (2008) Evolutionary
insights inferred by molecular analysis of the ITS1-5.8SITS2 and IGS Avena sp. sequences. Mol Phylogenet Evol
46:102–115
Nilsson B, Aberg E, Avholm K (1973) Flyghavretyper i Sverige.
Lantbrukshogskolans Meddelanden. No. 187
Nishiyama I (1929) The genetic and cytology of certain cereals.
I. Morphological and cytological studies in triploid, pentaploid and hexaploid Avena hybrids. Jpn J Genet 5:1–48
Nishiyama I, Yabuno T (1975) Meiotic chromosome pairing in
two interspecific hybrids and a criticism of the evolutionary
relationship of diploid Avena. Jpn J Genet 50:443–451
Nocelli E, Giovannini T, Bioni M, Alicchio R (1999) RFLP- and
RAPD-based genetic relationships of seven diploid species
of Avena with the A genome. Genome 42:950–959
O’Donoughue LS, Kianian SF, Rayapati PJ, Penner GA,
Sorrells ME, Tanksley SD, Phillips RL, Rines HW, Lee M,
Fedak G, Molnar SJ, Hoffman D, Salas CA, Wu B, Autrique
E, Van Deynze A (1995) A molecular linkage map of
cultivated oat. Genome 38:368–380
Oates JD, Burdon JJ, Brouwer JB (1983) Interactions between
Avena and Puccinia species. II. The pathogens: Puccinia
coronata Cda and P. graminis Pers. f. sp. avenae Eriks. &
Henn. J Appl Ecol 20:585–596
O’Donoughue LS, Wang Z, Roder M, Kneen B, Leggett JM,
Sorrells ME, Tanksley SD (1992) An RFLP-based linkage
map of oats based on a cross between two diploid taxa
(Avena atlantica A. hirtula). Genome 35:765–771
Ohm HW, Patterson FL (1973) A six-parent diallele cross analysis for protein in A. sterilis. Crop Sci 13:27–30
Ohm HW, Shaner G (1992) Breeding oat for resistance to diseases. In: Marshall HG, Sorrells ME (eds) Oat science and
technology. Agronomy Monographs No. 33. ASA, CSSA,
SSSA, Madison, WI, USA, pp 657–698
Paterson JG, Boyd WJR, Goodchild NA (1976) Vernalization
and photoperiod requirement of naturalized Avena fatua and
Avena barbata Pott ex Link in Western Australia. J Appl
Ecol 13:265–272
Peng YY, Wei YM, Baum BR, Chen GY, Dai SF, Zheng YL
(2009) Phylogenetic investigation of Avena genus (Poaceae:
Aveneae) and the maternal donor of Avena polyploids. BMC
Evol Biol
Perez de la Vega M (1997) Plant genetic adaptedness to climatic
and edaphic environment. In: Tigerstedt PMA (ed) Adaptation in plant breeding. Kluwer, Amsterdam, Netherland,
pp 27–38
Perez de la Vega M, Saenz de Miera LE, Garcia P (1998)
Collecting wild germplasm in Spain. In: Report of a Working Group on Avena. 5th Meeting, 7–9 May 1998, Vilnius,
Lithuania. ECP/RG, IPGRI, Rome, Italy, pp 65–69
Peterson DM, Brinegar AC (1986) Oat storage proteins. In:
Webster FH (ed) Oats: chemistry and technology. American
Association for Cereal Chemists, St. Paul, MN, USA, pp
153–204
Phillips TD, Murphy JP, Goodman MM (1993) Isozyme variation in germplasm accessions of the wild oat Avena sterilis
L. Theor Appl Genet 86:54–64
Pier D (1964) Evaluation and classification of Avena ssp.
collected from naturalized populations in Texas. Diss Abstr
64-7836
AU25
3 Avena
Pohler W, Hoppe HD (1991) Homeology between the chromosomes of Avena macrostachya and the Avena C genome.
Plant Breed 106:250–253
Popovic AO (1960) Neke osobine hibrida dodboijnih ukostanjem kulturnog i divljeg ovsa. Archiv poljopr Nauke 13:42
Popovic AO (1980) Divlji ovas kao nosilac gena pri nterspecies
hibridiza. Fragm Herbol Jugosl 9(2):37–45
Portyanko VA, Hoffman DL, Lee M, Holland JB (2001) A
linkage map of hexaploid oat based on grass anchor DNA
clones and its relationship to other oat maps. Genome
44:249–265
Pott JF (1799) Schrad Journ II:315
Qualset CO, Peterson ML (1978) Polymorphism for vernalization requirement in a winter oat cultivar. Crop Sci
18:311–315
Rajhathy T (1961) Chromosomal differentiation and speciation
in diploid Avena. Can J Genet Cytol 3:372–377
Rajhathy T (1963) A standard kariotype for Avena sativa. Can J
Genet Cytol 5:127–132
Rajhathy T (1966) Evidence and a hypothesis for the origin of
the C genome of hexaploid Avena. Can J Genet Cytol
8:774–779
Rajhathy T (1971a) The allopolyploid model in Avena. In:
Proceedings of 3rd Stadler Symposium, pp 71–87
Rajhathy T (1971b) Chromosome polymorphism in Avena ventricosa. Chromosoma 35:206–216
Rajhathy T, Baum BR (1972) Avena damascena: a new diploid
oat species. Can J Genet Cytol 14:645–654
Rajhathy T, Dyck PL (1963) Chromosomal differentiation and
speciation in diploid Avena: II. The karyotype of A. pilosa.
Can J Genet Cytol 5:175–179
Rajhathy T, Morrison JW (1959) Chromosome morphology in
the genus Avena. Can J Bot 37:331–337
Rajhathy T, Thomas H (1967) Chromosomal differentiation and
speciation in diploid Avena: III. Mediterranean wild populations. Can J Genet Cytol 9:52–68
Rajhathy T, Thomas H (1974) Cytogenetics of oats (Avena L.).
Miscellaneous Publication of the Genetics Society of
Canada, No. 2, Genetics Society Canada, Ottawa
Rajhathy T, Zillinsky FJ, Hayes JD (1964) Report on Canada–
Wales expedition. Canadian Department of Agriculture,
Ottawa
Rajhathy T, Zillinsky FJ, Hayes JD (1966) A collection of wild
oat Mediterranean region. Canadian Department of Agriculture, Ottawa
Razumov VI (1961) Environment and plant development.
Leningrad-Moscow, Selkhozizdat
Reich JM, Brinkman MA (1984) Inheritance of groat protein
percentage in Avena sativa A. fatua L. crosses. Euphytica
33:907–913
Rezai A (1978) Variation for some agronomic traits in the world
collection of wild oats (Avena sterilis L.). Diss Abstr Int
38.11.5129B
Rezai A, Frey KJ (1988) Variation in relation to geographical
distribution of wild oats – seed traits. Euphytica 39:
113–118
Rezai A, Frey KJ (1989a) Cytoplasmic effect on groat protein
content in interspecific control in interspecific matings of
Avena sativa L. and A. sterilis L. J Iowa Acad Sci
96:104–107
Rezai A, Frey KJ (1989b) Variation for physiological and morphological traits in relation to geographical distribution of
wild oats. SABRAO J 21:1–9
Rezai A, Frey KJ (1990) Multivariate analysis of variation among
wild oat accessions – seed traits. Euphytica 49:111–119
Rines HW, Halstead RP (1988) Agronomic evaluation of oat
cultivars with substituted Avena fatua and A. sterilis cytoplasm. Crop Sci 28:805–809
Rines HW, Stuthman DD, Briggle LW, Youngs VL, Jedlinski H,
Smith DH, Webster JA, Rothman PG (1980) Collection and
evaluation of Avena fatua for use in oat improvement. Crop
Sci 20:63–68
Rines HW, Gengenbach BG, Boylan KL, Storey KK (1983)
Comparison of oat cytoplasms by mitochondrial DNA analysis. Agron Abstr Am Soc Agron 78:253–268
Rines HW, Gengenbach BG, Boylan KL, Storey KK (1988)
Mitochondrial DNA diversity in oat cultivars and species.
Crop Sci 28:171–176
Rines HW, Molnar SJ, Tinker NA, Phillips RL (2006) Oat. In:
Kole C (ed) Genome mapping and molecular breeding in plants,
vol 1, Cereals and millets. Springer, New York, pp 211–242
Rines HW, Porter HL, Carson ML, Ochocki GE (2007) Introgression of crown rust resistance from diploid oat Avena
strigosa into hexaploid cultivated oat A. sativa by two methods: direct crosses and through an initial 2xþ4x synthetic
hybrid. Euphytica 158:67–79
Rines HW, Porter HL, Carson ML (2008) Suppressors of oat
crown rust resistance in interspecific oat crosses. In: 8th
International oat conference, 27 June–2 July 2008, Minneapolis, MN, Poster V-7. http://wheat.pw.usda.gov/GG2/
Avena/event/IOC2008/IOCprogram.html
Robertson LD, Frey KJ (1984) Cytoplasmic effects on plant
traits in interspecific matings of Avena. Crop Sci 24:200–204
Roderick HW, Jones ERL, Sebesta J (2000) Resistance to oat
powdery mildew in Britain and Europe: a review. Ann Appl
Biol 136(8):5–91
Rodionov AV, Tyupa NB, Kim EC, Machs EM, Loskutov IG
(2005) Genomic structure of the autotetraploid oat species
Avena macrostachya inferred from comparative analysis of
the ITS1 and ITS2 sequences: on the oat karyotype evolution
during the early stages of the Avena species divergence. Russ
J Genet 41:518–528
Rodionova NA, Soldatov VN, Merezhko VE, Yarosh NP,
Kobylyansky VD (1994) Cultivated flora: oat, vol 2, part 3.
Kolos, Moscow
Romero Zarco C (1984) Numeros cromosomicos para la flora
Espanoles. 300–364. Numeros 337–341. Lagascalia 12:
292–294
Romero Zarco C (1990) Las avenas del grupo barbata en la
Peninsula Iberica y Baleares. Lagascalia 16:243–268
Romero Zarco C (1994) Las avenas del grupo “sterilis” en la
Peninsula Iberica y regions adyacentes del SW de Europa y
NW de Africa. Lagascalia 17:277–309
Romero Zarco C (1996) Sinopsis del genero Avena L. (Poaceae,
Avenae) en Espana peninsular y Baleares. Lagascalia
18:171–198
Rooney WL, Rines HW, Phillps RL (1994) Identification of
RFLP markers linked to crown rust resistance genes Pc 91
and Pc 92 in oat. Crop Sci 34:940–944
I.G. Loskutov and H.W. Rines
Roshevitz RYu (1934) Genus 132. Avena L. Flora of the USSR,
vol 2. Publications of Academic Sciences, USSR, Leningrad,
pp 259–270
Roshevitz RYu (1937) Cereals. Nauka, Moscow- Leningrad
Roshevitz RYu (1951) Flora of Kirgizskaya SSR. Nauka,
Frunze, Kirgizskaya SSR
Rothman PG (1984) Registration of four stem rust and crown
rust resistant oat germplasm lines. Crop Sci 24:12–17
Sackville Hamilton N, Chorlton KH (1997) Regeneration of
accessions in seed collections: a dicision guide; IPGRI/
FAO Handbooks for genebanks 5. IPGRI, Rome, Italy
Sadanaga K, Zillinisky FJ, Murphy HC, Smith RT (1968) Chromosome association in triploid and tetraploid and pentaploid
of Avena magna (2n¼28). Crop Sci 8:594–597
Sadasivaiah RS, Rajhathy T (1968) Genome relationships in
tetraploid Avena. Can J Genet Cytol 10:655–669
Saidi S (1998) Summary of the Moroccan oat germplasm evaluation. In: Report of a working group on Avena, 5th Meeting,
7–9 May 1998. Vilnius, Lithuania, ECP/RG, IPGRI, Rome,
Italy, pp 32–33
Saidi N, Ladizinsky G (2005) Distribution and ecology of the
wild tetraploid oat species Avena magna and A. murphyi in
Morocco. In: Report of a cereals network, 1st Meeting. 3–5
July 2003, Yerevan, Armenia. ECP/GR, IPGRI, Rome, Italy,
pp 70–73
Sampson DR (1954) On the origin of cultivated oats. Bot Mus
Leaflets Harvard Univ 16:265–303
Sampson DR, Burrows VD (1972) Influence of photoperiod,
short-day vernalization, and cold vernalization on days to
heading in Avena species and cultivars. Can J Plant Sci
52:471–482
Sanchez de la Hoz P, Forminaya A (1989) Studies of isozymes
in oat species. Theor Appl Genet 77:735–741
Schipper H, Frey KJ (1991) Observed gains from three recurrent
selection regimes for increased groat-oil content of oat. Crop
Sci 31:1505–1510
Schreber JCD von (1771) Inter Avena sativam frequens occurit,
neglecta agricolisque ignota. Spicilegium Florae Lipsicae.
Leipzig
Schuler B (1978) Identification of wild oats and population
studies (Avena sterilis L.) in wheat in Morocco. In: Proceedings of the symposium on plant protection, 7–18 Aug 1978,
pp 15
Scurrah M, Barr AR, Tasker SD (1992) Breeding for resistance
and tolerance to oat stem nematode (Ditylenchus dipsaci) in
South Australia. In: Proceedings of 4th international oat
conference, vol 3, 19–23 Oct 1992, Adelaide, SA, Australia,
pp 62–65
Sebesta J, Kuhn F (1990) Avena fatua L. subsp. fatua v. glabrata
Peterm. subv. pseudobasifixa Thele. as a source of crown
rust resistance genes. Euphytica 50:51–55
Sebesta J, Zukova AE, Kummer M (1987) Dalsi zdroje specificke rezistence ovsa k Puccinia coronata var. avenae. Sbornik UVTIZ Genetika a Slechteni 23:117–124
Sebesta J, Roderick HW, Chong J, Harder DE (1993) The
oat line Pc54 as a source of resistance to crown rust,
stem rust and powdery mildew in Europe. Euphytica 71:
91–97
Sebesta J, Zwatz B, Roderick HW, Harder DE, Stojanovic S,
Corazza L (1999) Oat fungal diseases in Europe and their
genetic control. Pflanzenschutzberichte 58:152
Sebesta J, Roderick HW, Stojanovic S, Zwatz B, Harder DE,
Corazza L (2000) Genetic basis of oat resistance to fungal
diseases. Plant Prot Sci 36:23–38
Sebesta J, Zwartz B, Roderick HW, Corazza L, Starzyk MH,
Reitan L, Loskutov IG (2001) Incidence of Pyrenophora
avenae Ito et Kurib. in Europe between 1994-1998 and the
varietal reaction of oats to it. Plant Prot Sci 37:91–95
Sharma DC, Forsberg RA (1977) Spontaneous and induced
interspecific gene transfer for crown rust resistance in
Avena. Crop Sci 17:855–860
Sheidai M, Koobaz P, Termeh F, Zehzad B (2002) Phenetic
studies in Avena species and populations of Iran. J Sci Islam
Repub Iran 13:19–28
Shelukhina OYu (2008) Chromosomal and molecular marked of
species genera Avena L. PhD Dissertation Abstract, Vavilov
Instiute of General Genetics, Moscow
Shelukhina OYu, Badaeva ED, Loskutov IG, Pukhal’sky VA
(2007) A comparative cytogenetic study of the tetraploid oat
species with the A and C genomes: Avena insularis,
A. magna, and A. murphyi. Russ J Genet 43:613–626
Shelukhina OYu, Badaeva ED, Brezhneva TA, Loskutov IG,
Pukhalsky VA (2008a) Comparative analysis of diploid species of Avena L. Using cytogenetic and biochemical markers: Avena canariensis Baum et Fedak and A. longiglumis
Dur. Russ J Genet 44:694–701
Shelukhina OYu, Badaeva ED, Brezhneva TA, Loskutov IG,
Pukhalsky VA (2008b) Comparative analysis of diploid species of Avena L. Using cytogenetic and biochemical markers: Avena pilosa M. B. and A. clauda Dur. Russ J Genet
44:1087–1091
Shelukhina O Yu, Gorunova SV, Loskutov IG, Pukhalskiy VA,
Badaeva ED (2009) Comparative investigation of tetraploid
AB-genome Avena species using cytogenetic (C-banding
and FISH) and RAPD analyses. Plant Syst Evol (in press)
Shepeleva EM (1939) Karyological research of cultivated and
wild species of oat. Doklady AN SSSR 25(3):215–218
Simmonds NW (1993) Introgression and incorporation, strategies
for the use of crop genetic resources. Biol Rev 68:539–562
Simmonds NW (1995) The relation between yield and protein in
cereal grain. J Sci Food Agric 67:309–315
Simons MD (1965) Seedling resistance to Puccinia coronata
avenae race 264 found in Avena sterilis. Phytopathology
55:700–701
Simons MD (1979) Influence of genes for resistance to Puccinia
coronata from Avena sterilis on yield and rust reaction of
cultivated oats. Phytopathology 69:450–452
Simons MD (1985) Transfer of field resistance to Puccinia
coronata from Avena sterilis to cultivated oats by backcrossing. Phytopathology 75:314–317
Simons MD, Briggle LW (1984) Screening for tolerance to
Puccinia coronata in progenies of visually susceptible
strains of Avena fatua. (Abstract). Phytopathology 74:1271
Simons MD, Sadanaga K, Murphy HC (1959) Inheritance
of resistance to strains of diploid and tetraploid species of
oats to races of the crown rust fungus. Phytopathology
49:257–259
Simons MD, Martens JM, McKenzie RIH, Nishiyama I,
Sadanaga K, Sebesta J, Thomas H (1978) Oats: a standardized system of nomenclature for genes and chromosomes
and catalogue of genes governing characters. USDA Agricultural Handbook No 509, USDA, Washington, DC
AU26
3 Avena
Simons MD, Robertson LD, Frey KJ (1985) Association of
host cytoplasm with reaction to Puccinia coronata in progeny of crosses between wild and cultivated oats. Plant Dis
69:969–971
Simons MD, Michel LJ, Frey KJ (1987) Registration of three oat
germplasm lines resistant to the crown rust fungus. Crop Sci
27:369
Singh RS, Jain SK, Qualset CO (1973) Protein electrophoresis
as an aid to oat variety identification. Euphytica 22:98–105
Singh RP, Ma H, Aytrique E (1996) Suppressors for leaf rust and
stripe rust in interspecific crosses. In: Kema GHJ, Niks RE,
Daamen RA (eds) Proceedings of the 9th European and
Mediterranean Cereals Rusts Conference, 2–6 Sept 1996,
Lunteren, The Netherlands. European and Mediterranean
Cereals Rusts Foundation, Wageningen, The Netherlands,
pp 176–178
Soldatov VN, Merezhko VE, Loskutov IG (1990) Evaluation of
cultivated and wild oat species for tolerant to BYDV. Oat
Newsl 41:70
Spilde AL, Albrechtsen RS, Rumbaugh MD (1974) Relationship
of protein percent with other phenotypic characters in interspecific oat crosses. Crop Sci 14:767–769
Spooner D, van Treuren R, de Vicente MC (2005) Molecular
markers for genebank management. IPGRI Technical Bulletin No 10. IPGRI, Rome, Italy
Sraon HS, Reeves DL, Rumbaugh MD (1975) Quantative gene
action for protein content in oats. Crop Sci 15:668–670
Stanton TR (1955) Oat identification and classification. USDA
Technical Bulletin No:1100
Stebbins GL (1971) Chromosomal evolution in higher plants.
Edward Arnold, London, UK
Steidl RP, Webster JA, Smith DH (1979) Cereal leaf beetle plant
resistance: antibiosis in an Avena sterilis introduction. Environ Entomol 8:448–450
Stevens JB, Brinkman MA (1986) Performance of Avena sativa
L./Avena fatua L. backcross lines. Euphytica 35:785–792
Suneson CA (1948) Wild oat selection resistant to rust. J Am
Soc Agron 40:105
Suneson CA (1967a) Registration of Rapida oats. Crop Sci
7:168
Suneson CA (1967b) Registration of Sierra oats. Crop Sci 7:168
Suneson CA (1969) Registration of Montezuma oats. Crop Sci
9:527
Surface FM (1916) Studies on oat breeding. III. On the inheritance of certain glume characters in the cross Avena fatua
A. sativa var. Kherson. Genetics 1:252–286
Takeda K, Frey KJ (1976) Contributions of vegetative
growth-rate and harvest index to the grain yield of progenies from Avena sativa by Avena sterilis crosses. Crop Sci
16:817–821
Takeda K, Frey KJ (1985) Increasing grain yield of oats by
independent culling for harvest index and vegetative growth
index or unit straw weight. Euphytica 34:33–41
Takeda K, Frey KJ (1987) Improving grain yield in backcross
populations from Avena sativa A. sterilis matings by
using independent culling for harvest index and vegetative
growth index or unit straw weight. Theor Appl Genet
74:659–665
Takeda K, Bailey TB, Frey KJ (1985) Changes in mean,
variance, and covariation among agronomic traits in successive backcross generations of interspecific matings (Avena
sativa L. A. sterilis L.) of oats. Can J Genet Cytol
27:426–432
Thellung A (1911) Uber die Abstammung, den systematischen
Wert und die Kulturgeschichte der Saathafer-Arten (Avena
sativa Cosson), Beitrag zu einer naturlichen Systematic von
Avena sect Euavena. Veirteljahrsschr d Naturf Gesellsch
Zurich 54:311–345
Thellung A (1919) Neuere Wege und Ziele der botanischen
Systematik, erlautert am Beispiele unserer Getreidearten.
Naturwiss Wochenschr 17:32–33
Thellung A (1928) Die Ubergangsformen von Wildhafertypus
(Avena agrestes) zum Saathafertypus (Avena sativae).
Extrait du recueil des travaux botaniques Neerlandais. V
25a:416–444
Thomas H (1968) The addition of single chromosome of Avena
hirtula to the cultivated hexaploid oat A. sativa. Can J Genet
Cytol 10:551–563
Thomas H (1970) Chromosome relationships between the
cultivated Avena sativa (6x) and A. ventricosa (2x). Can J
Genet Cytol 12:36–43
Thomas H (1988) New species of Avena. In: Proceedings of
the 3rd international oat conference, 4–8 July 1988, Lund,
Sweden, pp 18–23
Thomas H (1992) Cytogenetics of Avena. In: Marshall HG,
Sorrells ME (eds) Oat science and technology. Agronomy
Monographs No. 33. ASA, CSSA, SSSA, Madison, WI,
USA, pp 473–507
Thomas H (1995) 29 Oats. Avena spp. (Gramineae – Aveneae).
In: Smartt J, Simmonds NW (eds) Evolution of crop plants,
2nd edn. Longman, London, UK, pp 132–137
Thomas H, Al-Ansari N (1988) Genotypic control of chromosome pairing in amphiploids involving the cultivated oat
Avena sativa L. Euphytica 37:37–45
Thomas H, Aung T (1978) The transfer of mildew resistance
from the tetraploid wild oat Avena barbata into the
cultivated oat. In: Interspecific hybridization in plant breeding. Proceedings of the 8th EUCARPIA Congress. II. Interspecific gene transfer. Madrid, Spain, pp 109–112
Thomas H, Griffiths N (1985) Oat cytogenetics. Alien chromosome substitution line. In: Annual Report of Welsh Plant
Breeding Station: 1984, pp 102–103
Thomas H, Jones ML (1965) Chromosomal differentiation in
diploid species of Avena. Can J Genet Cytol 1:108–111
Thomas H, Jones DIH (1968) Electrophoretic studies of proteins in Avena in relation to genome homology. Nature
220:825–826
Thomas H, Leggett JM (1974) Chromosome relationships
between Avena sativa and the two diploid species A. canariensis and A. prostrata. Can J Genet Cytol 16:889–894
Thomas H, Naqvi ZH (1991) Monosomic analysis of response to
vernalization winter oat. Euphytica 57:151–155
Thomas H, Thomas PT (1970) Cytology. In: Jubilee Report of
the Welsh Plant Breeding Station 1919–1969, pp 45–46
Thomas H, Leggett JM, Jones IT (1975) The addition of a pair of
chromosomes of the wild oat Avena barbala (2N ¼ 28) to the
cultivated as oat A. sativa L. (2N ¼ 42). Euphytica
24:717–724
Thomas H, Haki JM, Arangzeb S (1980a) The introgression of
characters of the wild oat Avena magna (2n ¼ 4x ¼ 28) into
the cultivated oat A. sativa (2n ¼ 6x ¼ 42). Euphytica
29:391–399
I.G. Loskutov and H.W. Rines
Thomas H, Powell W, Aung T (1980b) Interfering with regular
meiotic behavior in Avena sativa as a method of incorporating the gene for mildew resistance from Avena barbata.
Euphytica 29:635–640
Thompson RK (1966) Mesa, new oat for southern Arizona. Prog
Agric Arizona 18(3):8
Thompson RK (1967) Registration of Mesa oats. Crop Sci 7:167
Thro AM (1982) Feasibility of oats (Avena sativa L.) as an
oilseed crop. Diss Abstr Int 43. 5. 1326B
Thro AM, Frey KJ (1985) Inheritance of groat-oil content and
high-oil selection in oats (Avena sativa L.). Euphytica
34:251–263
Tinker NA, Kilian A, Wight CP, Heller-Katarzyna K, Wenzel P
et al (2009) New DarT markers for oat provide enhanced
map coverage and global germplasm characterization. BMC
Genomics 10:39
Tournefort JP (1700) Méthode pour reconnaı̂tre les Plantes.
Institutiones rei herbariae, editio altera, I
Trabut L (1909) Contribution a l’Etude de l’Origine des Avoines
cultivees Compt. Frend. Acad. Sci. Paris CXLIX:227–229
Trabut L (1914) Origin of cultivated oats. J Hered 5:74–85
Trofimovskaya AYa, Pasynkov VI, Rodionova NA, Soldatov VN
(1976) Genetic potential of section true oat of genus Avena
and it importance for breeding. Works Appl Bot Genet Plant
Breed 58(2):83–109
Udovenko GV (1977) Salt tolerance of cultivated plants. Kolos,
Leningrad, USSR
Valentine J (1987) Breeding cereals of high nutritional quality
with special reference to oats and naked oats. Asp Appl Biol
15:541–548
Valentine J, Bakewell EL, Welch RW (1994) Exploitation of the
genetic potential of oats for use in feed and human nutrition.
HGCA Project Report No 88E (2nd Report), pp 1–21
Van Deynze AE, Nelson JC, O’Donoughue LS, Ahn SN,
Siripoonwiwat W, Harrington SE, Yglesias ES, Brada DP,
McCouch SR, Sorrells ME (1995) Comparative mapping in
grasses. Oat relationships. Mol Gen Genet 249:349–356
Vavilov NI (1926) The centres of origin of cultivated plants.
Works Appl Bot Plant Breed 16:91–99
Vavilov NI (1927) Geographical regularities in relation to the
distribution of the genes of cultivated plants. Works Appl
Bot Genet Plant Breed 17:411–428
Vavilov NI (1951) The origin, variation, immunity and breeding
of cultivated plants. Translated by Chester KS. Ronald Press,
New York, NY, USA
Vavilov NI (1957) World resources of cereals, grain leguminous
crops and flax and their utilization in plant breeding. Agroecological survey of the principal field crops. AN USSR
Moscow–Leningrad, USSR
Vavilov NI (1962) About origin of cultivated rye. Selected works,
vol 3. Nauka, Moscow–Leningrad, USSR, pp 446–467
Vavilov NI (1964a) Study of plant immunity to infectious
diseases. (As applied to plant breeding purposes). Selected
works, vol 4. Nauka, Moscow- Leningrad, USSR, pp 314–399
Vavilov NI (1964b) Resistant varieties breeding as a main
method fighting to rust diseases. Selected works, vol 4.
Nauka, Moscow–Leningrad, USSR, pp 414–429
Vavilov NI (1964c) The lows of natural plant immunity to
infectious diseases. (Keys to finding immune forms).
Selected works, vol 4. Nauka, Moscow–Leningrad, USSR,
pp 430–488
Vavilov NI (1965a) Centers of origin of cultivated plants.
Selected works, vol 5. Nauka, Moscow–Leningrad, USSR,
pp 9–107
Vavilov NI (1965b) Universal centers of a wealth of types
(genes) of cultivated plants. Selected works, vol 5. Nauka,
Moscow–Leningrad, USSR, pp 108–119
Vavilov NI (1965c) The Linnean species as a system. Selected
works, vol 5. Nauka, Moscow–Leningrad, USSR, pp 233–252
Vavilov NI (1992) Origin and geography of cultivated
plants. Translated by Love D. Cambridge University Press,
London, UK
Vavilov NI (1997) Five continents. Translated by Love D.
IPGRI/VIR, Italy, Rome
Vavilov NI, Bukinich NI (1959) Agricultural Afghanistan.
Selected works, vol 1. Nauka, Moscow–Leningrad, USSR,
pp 45–360
Steudel von EG (1855) Avena wiestii. Synopsis Plantarum Glumacearum. Stuttgartiae. I. 231
Wahl I, Segal A (1986) Evolution of host-parasite balance in
natural indigenous populations of wild barley and wild oats
in Israel. In: Barigozzi C (ed) The origin and domestication
of cultivated plants symposium, 25–27 Nov 1985, Rome,
Italy, pp 129–141
Weibull J (1986) Screening for resistance against Rhopalosiphum padi (L.). I. Avena species and breeding lines. Euphytica 35:993–999
Weibull J (1988a) Resistance in the wild crop relatives Avena
macrostachya and Hordeum bogdani to the aphid Rhopalosiphum padi. Entomol Exp Appl 48:225–232
Weibull J (1988b) Free amino acids in the phloem sap from oats
and barley resistant to Rhopalosiphum padi. Phytochemistry
27:2069–2072
Weibull J, Hanson R (1986) Mojligheter till resistensforadling
mot bladloss i strasad. Vaxtskyddsrapporter Jordbruk 39:
39–44
Welch RW, Leggett JM (1997) Nitrogen content, oil content and
oil composition of oat cultivars (A. sativa) and wild Avena
species in relation to nitrogen fertility, yield and partitioning
of assimilates. J Cereal Sci 26:105–120
Welch RW, Leggett JM, Lloyd JD (1991) Variation in the kernel
(13)(14)-beta-D-glucan content of oat cultivars and wild
Avena species and its relationship to other characteristics. J
Cereal Sci 13:173–178
Welch RW, Brown JCW, Leggett JM (2000) Interspecific and
intraspecific variation in grain and groat characteristics of
wild oat (Avena) species: very high groat (1-3), (1-4)-b-Dglucan in an Avena atlantica genotype. J Cereal Sci
31:273–279
Welsh A (1945) Pythium root necrosis of oats. Iowa State Coll J
Sci 19:361–399
Wesenberg DM, Briggle LW, Smith DH (1992) Germplasm
collection, preservation and utilization. In: Marshall HG,
Sorrells ME (eds) Oat science and technology. Agronomy
Monographs No. 33. ASA, CSSA, SSSA, Madison,
WI, USA, pp 793–820
Whalley RDB, Burfitt JM (1972) Ecotypic variation in Avena
fatua L., A. sterilis L. (A. ludoviciana), and A. barbata Pott.
in New South Wales and southern Queensland. Aust J Agric
Res 23:799–810
Williams W, Verma UN (1956) Investigation on resistance to
disease among species of the genus Avena. 2. Resistance to
3 Avena
physiologic races of Puccinia coronata avenae and P. graminis avenae. Ann Appl Biol 44:56–71
Wilson WA, McMullen MS (1996b) Identification of RAPD
markers linked to Pc91. In: Proceedings of the 5th international oat conference, vol 2. 30 July–6 Aug 1996, Saskatoon,
Sask., Canada, pp 310–311
Wilson WA, McMullen MS (1997a) Recombination between a
crown rust resistance locus and an interchange breakpoint in
hexaploid oat. Crop Sci 37:1694–1698
Wilson WA, McMullen MS (1997b) Dosage dependent genetic
suppression of oat crown rust resistance gene Pc 62. Crop
Sci 37:1699–1705
Wong LSL, McKenzie RIH, Harder DE, Martens JW (1983)
The inheritance of resistance to Puccinia coronata and of
floret characters in Avena sterilis. Can J Genet Cytol
25:329–335
Yamaguchi H (1976) Taxonomy and distribution of weed oats in
Japan and Korea. In: Proceedings of the 5th Asian-Pacific
weed sci society conference, 1975, Tokyo, Japan, pp 34–37
Yamaguchi H (1977) Ecotypic variations of wild common oats
(Avena fatua L.) in East Asia. In: Proceedings of the 6th
Asian-Pacific weed science society conference, Indonesia,
vol 1, pp 123–131
Youngs VL, Peterson DM (1973) Protein distribution in the oat
(Avena sterilis L.) kernel. Crop Sci 13:365–367
Yu J, Herrmann M (2006) Inheritance and mapping of a
powdery mildew resistance gene introgressed from Avena
macrostachya in cultivated oat. Theor Appl Genet 113:
429–437
Zade A (1918) Der Hafer. Eine Monographie auf wissenschaftlicher und praktischer Grundlage Jena 2–1:355
Zadoo SN, Choubey RN, Gupta SK, Premachandran MN (1988)
Chromosomal stability in the backcross progenies of pentaploid hybrids between Avena sativa L. and A. maroccana
Gdgr. Plant Breed 100:316–319
Zelenskaya YaG, Konarev AV, Loskutov IG, Gubareva NK,
Strelchenko PP (2004) Characteristics of collection of
cultivated oat landraces (Avena sativa L.) for avenins polymorphism. Agrarnaya Rossiya 6:50–58
Zhou X, Jellen EN, Murphy JP (1999) Progenitor germplasm of
domesticated hexaploid oat. Crop Sci 39:1208–1214
Zillinsky FJ, Derick RA (1960) Crown rust resistant derivatives
from crosses between autotetraploid Avena strigosa and
A. sativa. Can J Plant Sci 40:366–370
Zillinsky FJ, Murphy HC (1967) Wild oat species as source of
disease resistance for improvement of cultivated oats. Plant
Dis Rep 51:391–395
Zillinsky FJ, Sadanaga K, Simons MD, Murphy HC (1959) Rust
resistant derivatives from crosses between Avena abyssinica
and Avena strigosa. Agron J 51:343–345
Zwatz B, Sebesta J, Corazza L, Herrmann M, Krolikowski J
(1994) Incidence of Septoria avenae Frank f. sp. avenae in
Europe in 1990-1993 and the varietal reaction of oats to it.
Pflanzenschutzb 54:129–135
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Please check if “Tunis” can be replaced with “Tunisia”
in the sentence “The accessions of...”
AU19
Please check if “Czechoslovakia” can be changed to
“Czech Republic and Slovakia” in the sentence “They
have geographically...”
AU20
Please clarify whether the reference is ‘Branson and
Frey 1989a or b.’
AU21
Please clarify whether the reference is ‘Cox and Frey
1984a or b’.
AU22
Please clarify whether the reference is Wilson and
McMullen 1997a or b throughout the text.
Author’s response
AU23
Following references are not cited in text: Baum
(1969), Cosson (1854), Cosson and Durieu de
Maisonneuve (1854), Frey (1981), Frey et al. (1985,
1986), Nocelli et al. (1999), Rajhathy and Dyck (1963),
Roshevitz (1951), Tinker et al. (2009), Vavilov (1997).
Kindly cite them in the text or delete them from
the list.
AU24
Please update the reference Maggioni et al. (2009)
AU25
Please update the reference Peng et al. (2009).
AU26
Please update the reference Shelukhina et al. (2009).