Assessing and understanding the variations existing in crops due to genetic composition and environmental variability is very important for exploiting the genetic constitution of crop plants using variability measures such as phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV), heritability and genetic advance are a major concern for common bean to identify important traits in common bean genetic improvement. The field experiment was conducted at Mandura and Dibatie research substations consisting of sixteen genotypes of common bean during 2017/18 in lattice design with three replications to evaluate the performance of common bean genotypes and estimate the genetic variability, heritability and genetic advance as a percent of mean in relation to yield and its component traits for future breeding program. Combined analysis of variance across locations revealed highly significant variations among genotypes for all traits under this study, indicating the genetic variability for the studied traits among the genotypes. GCV and PCV ranged from days to flowering (GCV=0.75, PCV=3.36) to number of pods per plant (GCV=13.74, PCV=15.91). All the tested traits expressed high heritability values except days to flowering with heritability value of 5%. High heritability coupled with genetic advance as a percent of mean was observed for number of pods per plant. Generally, the result of the study showed significant genetic variability among tested genotypes and simple selection for effective improvement of these traits.

Keywords: Common bean, Genetic variability, Heritability, Genetic advance, Ethiopia