GENOTYPIC VARIABILITY AND GENOTYPE X ENVIRONMENT INTERACTIONS FOR SEED-YIELD CHARACTERS IN ADZUKI BEAN (VIGNA-ANGULARIS)

An experiment was conducted during the rainy season of 1989 with 30 ge notypes and during 1990 with 40 genotypes of adzuki bean [Vigna angula ris (Willd) Ohwi and Ohashi] to study the variations in genotypic vari ability and genotype x environment interactions for seed yield and rel ated characters. Sufficient genetic variability was recorded for seed yield and 10 other yield-related characters. The magnitude of paramete rs of variability, viz phenotypic coefficient of variation (pcv), geno typic coefficient of variation (gcv), heritabiIlty 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 se asons, revealed the presence of genotype x environment (G x E) interac tion for all the 11 characters. The magnitude of coefficient of variat ion of G x E interaction was the highest for biological yield/plant (2 6.47%), 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 eliminati ng G x E interaction, the maximum expected genetic advance (as % of me an) would be for 100-seed weight and internode length. Promising genot ypes for harvest index, 100-seed weight, plant height and internode le ngth were also identified.