Assessment of Genetic Variability, Correlation and Path Analysis for Yield and Yield Attributing Traits in Indian Bean [Lablab purpures (l.) Sweet]

Abstract

Indian bean [Lablab purpureus (L.) Sweet] is an important tropical legume crop valued for its high nutritional, medicinal, and agronomic significance, contributing to food security, soil fertility, and farmers’ livelihoods in tropical and subtropical regions. Phenotypic and genotypic variances, along with correlation and path coefficient analyses, heritability estimates, and genetic advance, were computed for yield-attributing traits across 42 genotypes of Indian bean. The analysis of variance for ten distinct characters revealed significant differences, indicating considerable scope for selection and genetic improvement. High genotypic (GCV) and phenotypic (PCV) coefficients of variation observed for traits such as pods per raceme, pods per plant, pod length, pod width, pod weight, and seeds per pod reflect substantial underlying genetic variability. Furthermore, the combination of high heritability and high genetic advance for most of these traits suggests the predominance of additive gene action, implying that selection based on these characters would be highly effective for genetic improvement. In contrast, days to 50 per cent flowering and green pod yield per plant exhibited moderate genetic advance and/or heritability, indicating the influence of non-additive gene action and environmental factors, thereby limiting the effectiveness of direct selection. Correlation analysis revealed that green pod yield per plant had a strong positive association with pods per raceme, pods per plant and racemes per plant, suggesting that improvement in these traits would lead to enhanced yield. Path coefficient analysis further confirmed that pods per raceme, pod weight, racemes per plant, plant height and pods per plant exerted high positive direct effects on yield. Overall, the study suggests that emphasis should be given to traits such as pods per raceme, pods per plant, pod weight, and racemes per plant during selection, as they are key contributors to green pod yield improvement in Indian bean.