Integrative Genetic Association and Path Coefficient Analysis for Dissecting Complex Trait Architecture in Black Gram (Vigna mungo L. Hepper)

Abstract

The present investigation was conducted at the Field Experimentation Centre, Department of Genetics and Plant Breeding, Naini Agricultural Institute, SHUATS, Prayagraj, Uttar Pradesh during the Zaid season of 2019. Fifty diverse genotypes of black gram were evaluated under field conditions to assess character association and contribution of yield-attributing traits through correlation and path coefficient analyses. The experimental site, located along the Prayagraj–Rewa National Highway, benefited from institutional support for resources and management, ensuring successful trial execution. Results revealed highly significant genotypic differences (p ≤ 0.05) across all 12 studied traits, indicating substantial genetic variability with potential for crop improvement. Phenotypic and genotypic correlations demonstrated that seed yield per plant was significantly and positively associated with days to 50% flowering, plant height, number of pods per plant, pod length, 100-seed weight, biological yield, and harvest index, while number of branches per plant exhibited a significant negative association. Path analysis revealed that traits such as number of pods per plant, pod length, biological yield, and harvest index exerted the strongest positive direct effects on seed yield, while traits like number of seeds per pod and number of branches per plant showed negative direct effects. These results suggest that these yield-contributing traits play pivotal roles in black gram productivity. The findings reinforce the importance of targeting both direct and indirect contributors to yield in breeding strategies, supporting the development of high-yielding black gram cultivars for diverse agro-climatic conditions. The path analysis shows that primary branches per plant, clusters per plant, pods per plant, and harvest index significantly contribute to higher yield in black gram. To improve the crop, selecting for these traits together would be most effective.