A Scientific Study of the Probable Reasons Causing the Loss of Citrus Indica from the Ecosystem

Abstract

The family of Citruses is diverse and found in almost all parts of the world. But very few people know that it originated in the Nokrek Biosphere Reserve of the land of clouds, Meghalaya, in India with the name of Citrus indica or the Indian Wild Orange. It was discovered in 1928 by Tanaka and was widespread in the adjoining states of Meghalaya. But with time, the plant became endemic to Nokrek Biosphere Reserve. However, few plants were reported in Behali Reserve Forest, Assam, and a plant was reported in Dailong Forest, Manipur.

The disappearance of the progenitor from the ecosystem will be a great loss to biodiversity. Therefore, an attempt was initiated to study the reasons causing its reduction from the earth. Reference was made from published literature to study its present status and assess its morphological features such as size, colour, shape, number of segments in each fruit, seed size, seed numbers, etc. Along with these, biochemical characterization of the fruit such as pH, TSS and juice content of the fruit have been determined. The descriptive sensory evaluation of the juice of Citrus indica using the 9-point Hedonic scale was also addressed. Major threats to the plant have been observed to be the geographical location of the Citrus indica as a plant, agricultural pressure on the population residing in the area to grow crops of commercial importance, urbanization and finally, climate change.

In case of morphological study, the fruit of C. indica was observed to have 8–10 segments with a varying number of seeds. Some fruits have a maximum of 14 seeds, while others may have only one seed. Thus, in case a fruit has only one or two seeds, the success rate of survival of the seed decreases. In the physico-chemical study, the juice of the fruit was found to be highly acidic with a pH of 2.49 and the total juice content was also too less (15%). The TSS of the fruit juice was found to be 7.3%.

The sensory evaluation presented variable opinions from the panellists in terms of colour, flavour, aroma, texture, etc. The average score given by the panellists for the colour was 6.75 which meant that they moderately liked the colour of the fruit juice. On the other hand, for flavour, the score was 5.37 and thereby conveying that the panellist neither liked nor disliked the taste. The scores were 7.35 (liked moderately) and 7.5 (moderately liked) for aroma and texture of the fruit juice, respectively.

Interviews with the locals helped in reporting the growth of some C. indica plants in the wild and beyond the buffer zone of Nokrek Biosphere Reserve. Realization was brought about that since consumers were not preferring the taste, people were not keen on growing the plant. Accordingly, its unpopularity would be the main reason that the plant is not cultivated and henceforth eventually become endangered. With the exploration of the knowledge of its goodness and its potential in generating income, the plant could be saved from getting extinct.