Genetic Variability, Diversity and Association Studies in Greengram [Vigna radiata (L.) Wilczek]

Abstract

Mung bean (Vigna radiata L. Wilczek) is a nutritionally rich pulse crop valued for its protein content and soil fertility enhancing properties, yet its yield improvement remains constrained by complex genetic and environmental interactions. Although previous studies have examined variability or trait associations in mung bean, few have integrated multiple biometrical approaches to simultaneously quantify variability, correlations, path effects, and genetic diversity across a large set of genotypes. This study evaluated 60 genotypes sourced from NBPGR during Kharif 2024 in a randomized block design to quantify genetic variability, trait associations, and diversity for 11 agro-morphological traits. Substantial variation was observed, with seed yield per plant ranging from 3.29 g to 17.35 g and recording the highest coefficient of variation (12.50%). Days to 50% flowering exhibited the lowest variability, underscoring its stability across genotypes. Correlation analysis revealed strong positive associations of seed yield with pod yield per plant (r = 0.749**), test weight (r = 0.395**), and number of seeds per pod (r = 0.295**), while negative associations were noted with plant height and flowering time. Path analysis confirmed pod yield per plant as the most influential determinant of seed yield, exerting the highest direct effect (0.7653). Cluster analysis grouped genotypes into seven distinct clusters, with Cluster IV being the largest, and principal component analysis indicated that the first six components explained 81.5% of total variation. Collectively, these results highlight the potential of exploiting diverse and high-performing genotypes, particularly those combining early flowering with high pod yield, as parents in breeding programs aimed at yield improvement in mung bean.