Genetic Divergence Analysis in Greengram [Vigna radiata (L.) Wilczek] under Rice Fallow Conditions
G. Monica *
Agricultural College, Naira, Acharya N G. Ranga Agricultural University, Andhra Pradesh, India.
K. Madhu Kumar
Agricultural Research Station, Ragolu, Acharya N G. Ranga Agricultural University, Andhra Pradesh, India.
L. Suryanarayana
Agricultural College, Naira, Acharya N G. Ranga Agricultural University, Andhra Pradesh, India.
M. Srinivasa Rao
Agricultural Research Station, Ragolu, Acharya N G. Ranga Agricultural University, Andhra Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
Greengram [Vigna radiata (L.) Wilczek] is an important short-duration pulse crop for rice fallow conditions, where genetically diverse and high-yielding genotypes are required for crop improvement. This study assessed genetic divergence among 30 greengram genotypes using Mahalanobis’ D² statistics and principal component analysis. The experiment was conducted in a randomised block design with two replications during Rabi 2025–26 at Agricultural Research Station, Ragolu, Andhra Pradesh. Eleven quantitative traits were recorded, including phenological, plant growth, pod, seed and yield-related characters. Tocher’s method grouped the genotypes into five clusters, indicating substantial variability. Cluster I comprised the maximum number of genotypes, whereas Cluster III was monogenotypic. The highest inter-cluster distance was observed between Clusters IV and V, suggesting that genotypes from these clusters may serve as useful divergent parents. Cluster IV recorded the highest mean seed yield per plant. Among the traits, 100-seed weight contributed the highest proportion to total divergence, followed by plant height and number of pods per plant. The first four principal components explained 84.64% of the total variation, with PC1 accounting for 45.73%. Days to 50% flowering, number of primary branches per plant, number of pods per plant, pod length, days to maturity and seed yield per plant contributed to genotype differentiation. Genotypes DGG 1, DGGV 2, MGG 295, ML 818, MGG 351 and LGG 600 were identified as relatively distinct and may be useful genetic resources for greengram breeding under rice fallow conditions.
Keywords: Genetic divergence, Greengram, Vigna radiata, rice fallow, Mahalanobis’ D² statistics, principal component analysis, Tocher’s clustering, yield traits, 100-seed weight, germplasm diversity