Genotypic variability and genotype x environment interactions for seed-yield characters in adzuki bean (Vigna angularis)

Abstract

An experiment was conducted during the rainy season of 1989 with 30 genotypes and during 1990 with. 40 genotypes of adzuki bean [Vigna angularis (Willd.) Ohwi & Ohashi] to study the variations in genotypic variability and genotype X environment interactions for seed yield and related characters. Sufficient genetic variability was recorded for seed yield and 10 other yield-related characters. The magnitude of parameters of variability, viz phenotypic  coefficient of variation (pcv), genotypic coefficient of variation (gov), heritability and genetic advance, was more in 1990 than 1989 due to the inclusion of derivatives from a cross involving indigenous x exotic genotypes. Combined analysis of variance for different years, using 21 common genotypes in both the seasons, revealed the presence of genotype x environment (G x E) interaction for all the 11 characters. The magnitude of coefficient of variation of G x E interaction was the highest for biological yield/plant (26.47%), followed by seed yield/plant (21.83%), harvest index (21.65%) and plant height (18.78%), and was higher than the genotypic variation. For other characters the variances for , genotypic variability and G x E interaction were more or less of similar magnitude. After eliminating G x E interaction, the maximum expected genetic advance (as % of mean) would be for 100-seed weight and internode length. Promising genotypes for harvest index, 100-seed weight, plant height and internode length were also identified.