Genetic analysis of yield and yield components and powdery mildew resistance in F4 and F5 populations of blackgram

The present investigation aimed to evaluate 96 F4 and F5 genotypes, including two parental lines (VBN11 and LBG17) of blackgram, across two locations for yield, yield components, and resistance to powdery mildew. Pooled analysis, genetic variability assessment, correlation studies, parent-regression coefficient analysis, and the Multi-trait Genotype Ideotype Distance Index (MGIDI) were performed. Combined ANOVA revealed significant differences for all the traits studied. In the combined analysis, genotypes G3 and G1 exhibited desirable yields along with powdery mildew resistance. High heritability and genetic advance as a percentage of the mean (GAM) were observed for the traits such as single plant yield, the number of pods per plant, and percent disease index (PDI). Seed yield per plant recorded significant and positive correlations with the number of clusters per plant, number of pods per plant, number of seeds per pod, and 100-seed weight in both generations. Among the traits, PDI showed the highest regression coefficient. Principal component analysis exhibited four principal components (PCs) explaining the total variance in the F4 and F5 generations. The MGIDI index analysis revealed a total genetic gain for specific traits, including the number of pods per plant, single plant yield, and the number of capsules per plant in the F5 generation. Genotypes G18, G19, G4, and G38 were identified as valuable genetic resource through MGIDI, contributing significantly to blackgram improvement for high yield and powdery mildew resistance.