Genetic Variability Studies in Advanced Segregating Generation for Biometrical Traits in Cowpea (Vigna unguiculata (L) Walp)

Abstract

Pulses have a vital and diverse role in agricultural systems and the food habits of people around the world. Among them, cowpea is a traditional and important pulse crop. It is a potential source of vegetable protein for the majority of Kerala's population. Crop improvement programmes aim to breed crops for diverse objectives, and developing high-yielding cowpea genotypes is a major and challenging objective in any breeding programme. To identify potential segregants with high yield and yield-contributing characters from an inter-varietal cross of cowpea, an experiment was conducted in the Department of Plant Breeding and Genetics, Kerala Agricultural University during 2023. In this research, the advanced generation of a cross between Vellayani Jyothika, a high-yielding variety susceptible to pod borer, and EC 98668, an exotic germplasm line resistant to pod borer but with low yield, was evaluated for genetic variability and to isolate promising segregants with high seed yield and yield-contributing characters. Parameters such as phenotypic coefficient of variance (PCV), genotypic coefficient of variance (GCV), heritability (H2) and genetic advance (GA) were estimated for nine quantitative characters from 230 plants belonging to 23 families. Grain yield per plant, number of pods per plant, plant height and pod length recorded high PCV and GCV, which indicated the existence of ample variability for these traits in the population; the narrow differences between PCV and GCV indicated a negligible environmental effect on trait expression. Number of pods per plant, plant height, pod length, seeds per pod, 100 seed weight and grain yield per plant recorded high heritability alongside high GAM. This indicates lower environmental influence and strong, fixable additive genetic variance in trait expression. Segregants with high yield and yield-contributing characters were identified and advanced to subsequent generations.