New Initiatives in Quick Bitter Gourd Breeding

Abstract

Bitter gourd (Momordica charantia L.) is an important vegetable crop known for its anti-diabetic properties. This crop is native to Indian regions, and therefore a significant diversity is recorded in this species in this region. Among the species identified so far, only seven species are believed to be distributed in India, and the rest of the species are most found in other parts of Southeast Asia and Africa. Among the cultivated species, M. charantia is economically most important and cultivated in several parts of the world. Most of the species under Momordica are dioecious in nature except M. charantia and M. balsamina. Besides monoecism, other sex form like gynoecism has been reported in M. charantia and utilized widely in hybrid breeding and development of predominantly gynoecious cultivars. Taxonomic classification of the different species is based on leaf shape, presence of lobes, flower characteristics such as sepal colour, sepal shape, petal colour, petal shape, inflorescence type, type of ovary, fruit, shape, size and colour and seed traits. Sex modification through application of different plant growth regulators is very common to obtain a greater number of female flowers per plant like several other cucurbitaceous vegetable crops. The studies on application of molecular markers in understanding the extent of diversity, phylogenetic relationship and characterization of economically important traits were started in the last decade. Recently, the draft genome sequencing has been reported from a research group in Japan. Thereafter, several molecular markers were developed for their use in functional genomics. Analysis based on RNS-seq also helped in understanding important traits including the sex expression. However, the genome sequence available is not of high quality and needs to be refined further. Most of the agronomically important traits and traits related to anti-diabetic properties need to be investigated in depth for better understanding and adopting accelerated breeding strategies in this crop.