GENETIC VARIABILITY AND CHARACTER ASSOCIATION IN COMMON BEAN (Phaseolus vulgaris L.) GENOTYPES IN SOUTH ETHIOPIA

Abstract

Genetic variability in crop species is important for improving the crops and enhancing production. Therefore, 36 common bean genotypes were evaluated for growth, yield and yield related traits, at Arba Minch and Areka, Southern Ethiopia during 2022 in main cropping season (July up to September). The field experiment was laid out in 6x6 simple lattice design. Soft wares used for data analysis were Anova using proc lattice model with sas 9.3, for mean comparison DMRT and for principal component analysis and clustering Minitab. The analysis of variance revealed significant (p<0.01) differences among genotypes. The variations observed among genotypes for grain yield ranged from 1537.5 kg/ ha for ADP0081 to 4747.7 kg/ha for ADP0570 with the overall mean value of 2934.3 kg/ha. High values of heritability (H2b) and genetic advance as percent of mean (GAM) along with high genotypic coefficient of variation (GCV) for the traits like number of seeds per plant, seed yield per hectare, harvest index, seed yield per plant, pod per plant, seed per pod, plant height, internode length, above ground biological yield per hectare suggesting that environment had brought no significant effect on the above traits considered as favourable traits for common bean improvement through effective phenotypic selection of these traits and high expected genetic gain from selection for these characters can be achieved. Seed yield showed a positive and significant phenotypic and genotypic association with seed per pod, number of seeds per plant, seed yield per plant and above ground biological yield per hectare. This indicating these traits could be the main contributors to grain yield. Principal component analysis (PCA) revealed that, the first six components accounted for (71%) of the total phenotypic variation among 36 common bean genotypes evaluated for fourteen quantitative traits. The genotypes were clustered into four groups, indicating the presence of genetic variability among the tested genotypes of common bean following the phenotypic traits under consideration. In conclusion, this study’s result showed that sufficient genetic variability among the common bean genotype studied, which could be used to improve the yield and other agronomic traits of the crop through selection or hybridization.