Capsicum Phylogeny and Domestication

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1 Capsicum Phylogeny and Domestication
Brian Walsh

2 Subfamily: Solanoideae Tribe: Capsicinae (since 1999)
Family: Solanaceae Subfamily: Solanoideae Tribe: Capsicinae (since 1999) Estimated 25 species (my count =37) Native to South and Central America Current distribution is global One of the most utilized spice in the world Part of human diet for 9000 years All diploid Typically self-fertilize Most n=12 (some n=13)

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4 One of the most diversely utilized plants
Spice Food Dye Medicine Weapons Poison Drinks Deterrent Insecticide/Pesticide Preservative Snuff Rituals Tribute Town Names Punishment

5 Domestication Davenport (1970) proposes all five domesticated species arose from a single ancestor (C. frutescens L.) (Lumper) (based on morphology) Heiser (1971) proposes each domesticated species arose from its own unique wild ancestor (Splitter) (hybridization studies) Pickersgill (1972) agrees with Heiser - different cultivated species show a combination of characters suggesting domestication by different groups of people living in different areas. Eshbaugh (1983) argues at least three distinct domesticated lineages based on morphology, plant breeding and enzyme analysis (C. chacoense is plesiomorphic)

6 Agricultural Centers of the New World and the theoretical flow of speciation
View from km above 5°18’S 63°55’W Based on C. chacoense

7 Domesticated Characters in Capsicum
Wild Gigantism of fruit Altered fruit shape Fruit color other than red Retained on peduncle a maturity Variable capsaicin levels small fruit Fruit round Red fruit Peduncle dehiscence at maturity High capsaicin levels

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9 Capsicum annuum

10 Eshbaugh’s breakdown into flower color categories (why?)
Capsicum annuum complex C. annuum var. annuum C. annuum var. avicular C. frutescens white flowers C. chinense C. chacoense Capsicum baccatum group C. baccatum var. praetermissum white flowers with yellow spots C. baccatum var. pendulum C. baccatum var. baccatum Capsicum eximium complex C. pubescens C. eximium purple flowers C. cardenasii Total species=8

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13 C. frutescens Tabasco

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15 C. baccatum var. praetermissum

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17 Capsicum eximium

18 Capsicum eximium C. baccatum var. praetermissum

19 Only species that strictly outcrosses
Capsicum cardenasii Only species that strictly outcrosses

20 Flower color classification of Capsicum
Color categories inaccurate (too many exceptions) Only a fraction of total species included Doesn’t agree with molecular data

21 Current phylogenetic questions
Monophyly of genus Resolving species relationships

22 Capsicum Monophyletic?
Modified from Bohs & Olmstead 1997

23 A B C A B C = Monophyletic A A C A A C = Not Monophyletic

24 Walsh 2001 (chloroplast atpB-rbcL spacer data)

25 Walsh 2001 (chloroplast atpB-rbcL spacer data)

26 Walsh 2001 combined atpB-rbcL spacer and waxy data n=12/13

27 Walsh 2001 (chloroplast atpB-rbcL spacer data)

28 Capsicum monophyly Intact for the time being
Odd C. ciliatum seems to be the weak link (n=13)

29 Mascone’s missing tree
Flow cytometry and Feulgen densitometry 1C-value of DNA = an equation for calculating genome size in absolute units Genome size in Mbp

30 Visualization of Mascone’s results
Capsicum anuum complex C. annuum var. annuum C. annuum var. avicular C. frutescens white flowers C. chinense C. chacoense United by similar DNA amount and little heterochromatin

31 1C G C. chacoense C. annuum var. annuum C. frutescens C. chinense

32 Capsicum baccatum group
C. baccatum var. praetermissum white flowers with yellow spots C. baccatum var. pendulum C. baccatum var. baccatum C. baccatum var. umbilicatum New variety described in 1998 Domesticated status unknown Similar DNA amounts – not surprising

33 C. baccatum var. pendulum 3.69 3621
1C G C. chacoense C. annuum var. annuum C. frutescens C. chinense C. baccatum var. pendulum C. baccatum var. baccatum C. baccatum var. umbilicatum Interpreted from data – not explicitly stated

34 Capsicum eximium complex
C. pubescens C. eximium purple flowers C. cardenasii C. parvifolium synonym with C. cardenasii? (but description is off – tree?) C. parvifolium only compared to C. campylopodium points out distantly related and nothing more C. campylopodium groups with C. pubescens – large genome size, and large amounts of heterochromatin forming complex patterns (tone implies trepidation) C. eximium has DNA content intermediate between C. baccatum and C. pubescens, but genome size supports close relationship to C. pubescens as well as isozyme and cross studies

35 ? ? 1C G C. chacoense 3.35 3273 C. annuum var. annuum 3.38 3312
C. annuum var. annuum C. frutescens C. chinense C. baccatum var. pendulum C. baccatum var. baccatum C. baccatum var. umbilicatum C. eximium C. pubescens ? C. campylopodium ? C. parvifolium/cardenasii

36 However, Mascone claims his data supports his hypothesis
Increase in DNA amount is evolutionary advancement C. chacoense most plesiomorphic (ancestral) C. campylopodium most advanced n=13 in more recently evolved

37 Mascone tree rooted ? Least DNA C. chacoense C. annuum var. annuum
C. frutescens C. chinense C. baccatum var. pendulum C. baccatum var. baccatum C. baccatum var. umbilicatum C. eximium C. pubescens Most DNA C. campylopodium x=13 ? C. parvifolium/cardenasii

38 Mascone molecular ? ? Least DNA C. chacoense C. annuum var. annuum
C. frutescens C. chinense C. baccatum var. pendulum C. baccatum var. baccatum C. baccatum var. umbilicatum C. eximium C. pubescens Most DNA C. campylopodium x=13 ? ? C. parvifolium/cardenasii ancestral

39 X=13 species C. ciliatum C. buforum C. campylopodium C. cornutum
C. schottianum C. villosum C. pereirae * C. friburguense * 3 unnamed Capsicum

40 Capsicum flexuosum

41 n = 13 n = 12

42 Conclusion Capsicum needs more research
Appears to be an x=12/x=13 split in distant past research hindered by incomplete sampling Difficult to study domestication when phylogeny unresolved 6 new species identified in last 8 years

43 Naga Morich

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52 Following Photos unused in presentation

53 Cherrapeño

54 Cherry Pepper Bolivian rainbow

55 Chilaca Fluorescent

56 Fredrik from Amalfi

57 Jalapeño - Biker Billy

58 Lemon black pepper Little nubian

59 O'odham Indian Piquin

60 Peter Pepper Pimenta-Doce

61 Poblano Suryamukhi

62 Tepin Variegata

63 C. Frutescens Naga Jolokia / Tezpur

64 Tabasco PI451762

65 C02466 Antillerna (Paris) C. chinense

66 Capsicum galapagoense

67 C. chacoense PI Putapario

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69 C. Pubescens

70 Capsicum eximium praetermissum

71 C. ciliatum

72 Capsicum Cardenasii

73 C. tovarii