Genetic variability and multi-trait analysis for enhanced yield stability under acid soil stress in common bean (Phaseolus vulgaris L.)

Soil acidity and low soil fertility are the bottlenecks to sustaining common bean production and productivity. Enhancing stable varieties needs understanding genetic variability and selecting genotypes based on multiple traits across environments for soil acidity tolerance. This study was aimed to determine genetic variability, trait associations, and identify superior genotypes for soil acidity tolerance via multi-trait biplot analysis. A total of 300 common bean genotype were evaluated using Alpha lattice Design with two replications across two locations under lime treated and lime untreated acidic soil conditions during the 2022 growing season. ANOVA revealed highly significant ( P < 0.001) genotypic variation and genotype-by-management interactions effects for all traits, indicating substantial genetic variability. Mean grain yield was 2331 kg/ha under lime treated conditions, ranging from 974.5 kg/ha (CB97) to 3464.4 kg/ha (CB81). Under soil acidity stress, mean grain yield declined to 1424 kg/ha, ranging from 309.96 kg/ha (CB97) to 2313.14 kg/ha (CB82), reflecting a 38.9% of reduction due to soil acidity stress. Phenotypic Coefficient of Variation ranged from 5.53 to 43.81%, while Genetic Coefficient of Variation ranged from 1.79 to 25.02%. Broad sense heritability ranged from 12.87 to 93.6% s and genetic advance as percentage of mean ranged from 1.46 to 51.69%. Genotype by traits and Genotype by Yield by Trait biplots analyses revealed positive associations for most traits across acidic soil environments, confirming the feasibility of selecting genotypes for balanced performance. Genotypes CB82 and CB231 were superior and stable, while CB151 (SMR241), CB82 (KSGPC25), CB57 and CB231 (CB170044-42-1) identified as promising candidates for breeding acid-tolerant, high-yielding varieties of common bean. In the future, the application of molecular markers to identify genes for soil acidity tolerance will be crucial for using the information to improve breeding efficiency in beans.