Genetic diversity of female clones of pointed gourd (Trichosanthes dioica Roxb.) based on multivariate analysis and inter simple sequence repeat (ISSR) marker

Abstract

Pointed gourd (Trichosanthes dioica Roxb.) is a vegetatively propagated and an underutilised cucurbitaceous vegetable crop of India and Bangladesh. The crop has not yet been characterized based on distinctiveness, uniformity, and stability (DUS) characters. Clonal diversity has also not been properly assessed utilizing multivariate analysis and molecular marker. The present investigation was carried out to analyse genetic diversity of 34 female clones employing 29 qualitative and 27 quantitative characters for multivariate analysis and inter simple sequence repeat (ISSR) markers. Shannon–Wiener Diversity Index (H’) suggested that plant and fruit morphological characters viz., fruit shape, fruit apex shape at blossom end, number of secondary branches up to 20th node, leaf colour, petiole length, leaf blade length, vine length, fruit skin primary colour, and depth of leaf lobing should be considered when evaluating pointed gourd genotypes for DUS testing. The clones grouped in six clusters which do not correspond to origin locations. Principal components of variable traits for number of secondary branches up to 20th node, leaf blade length, leaf blade width, leaf blade size, petiole length, number of leaf lobes, vine length, node at which 1st female flower appeared, days to 50% flowering and fruit weight had eigen values > 1 and accounting for 81.06% of total variation. Based on average values, multivariate, and molecular analysis of economic traits, the female clones, ‘BCPG-4’ and ‘Swarna Alaukik’ emerged as potential and diverse genetic stocks for future breeding programme. Classification of the female clones and their diversity could conveniently be analysed using ISSR markers. We could frame the possible ways of future improvement strategies of pointed gourd.