Combining Ability and Gene Action for Yield and Component Traits in Green Gram [Vigna radiata (L.) Wilczek] Using Line × Tester Analysis

Abstract

Background: Green gram (Vigna radiata L.) is an important short-duration pulse crop, and its improvement requires reliable information on parental combining ability and the gene action governing yield-related traits. Aims: The study aims to assess combining ability and gene action for agronomic traits using a line × tester mating design in green gram (Vigna radiata L.). Study Design: Line × tester mating design. Place and Duration of Study: Experimental Farm, Department of Genetics and Plant Breeding, College of Agriculture, Latur, during the summer season of 2025–26. Methodology: A line × tester mating framework comprising three female lines (TAKM-140, PANT-M-5 and SML-668), seven male testers (BMB-2302, BMB-2311, BMB-2314, BMB-2315, BPMR-32, BPMR-48 and BPMR-93) and one standard check variety (BM-2003-2) was used to develop 21 cross combinations. The 21 hybrids, their ten parents and the check variety were evaluated. Field observations were recorded for ten quantitative traits: days to 50% flowering, days to maturity, plant height (cm), number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant, number of seeds per pod, 100-seed weight (g) and seed yield per plant (g). Results: Combining ability analysis identified PANT-M-5 and testers BMB-2314, BMB-2315 and BPMR-32 as effective general combiners for seed yield and earliness. The crosses TAKM-140 × BMB-2302, PANT-M-5 × BPMR-32 and SML-668 × BMB-2311 showed significant positive specific combining ability (SCA) effects for seed yield per plant. Gene action analysis indicated that specific combining ability variance (\(σ^2_{SCA}\)) exceeded general combining ability variance (\(σ^2_{GCA}\)) for all evaluated traits. Furthermore, the variance ratio (\(σ^2_{SCA}\)/\(σ^2_{GCA}\)) was less than unity for all traits. Conclusion: The findings indicated a predominance of non-additive gene action in the inheritance of the evaluated agronomic traits. Breeding approaches such as biparental mating or recurrent selection in early segregating generations may therefore be used to exploit this non-additive variance for crop improvement.