Genetic Variability and Character Association for Advanced Faba bean (Vicia faba L.) Genotypes in Southeastern Ethiopia

Genetic variability refers to the tendency of genetic traits to differ within and among populations. In the 2023 growing season, 36 genetically distinct faba bean genotypes were evaluated across two locations using an alpha lattice design with two replications. The study aimed to assess genetic variation and identify parent materials with desirable traits. A combined analysis of variance indicated a highly significant (P < 0.001) difference among 36 faba bean genotypes for all studied traits, except for days to 50% flowering and reaction to rust disease. The phenotypic coefficient of variation is higher than the genotypic coefficient of variation for all traits except days to maturity and the number of seeds per pod. This suggests that the environment plays a significant role in the expression of genes for these traits. The genetic advance as a percentage of the mean ranged from 0.27% for days to flowering to 34.25% for thousand seed weights. The genotypic coefficients of variations were relatively higher in 1000-seed grain weight and number of pods per plant. The highest broad-sense heritability of 94% was recorded in days to maturity, and the lowest heritability of 16% was observed in plant height. The genotype-by-trait graph formed, the angles between the number of seeds per pod and rust were smaller than 90°, indicating a positive correlation between these traits. The genotypes that have been tested come from different breeding stages. The genetic variability of the traits becomes narrower or shifts towards more uniform characteristics due to selection. Therefore, unless a more diverse population is used and testing locations are increased, more genetic variance is not expected.