Implications of gene action on the selection of cooking time in common bean

The cooking time of common beans is crucial for consumer acceptance, although its genetic basis is not yet fully understood. Thus, the objective of this study was to estimate the components of genotypic variation to verify the predominance of gene action and its implications for improving the cooking time trait in common beans. The genotypes used were obtained from a cross between the parents BAF50 x BAF07, with 16 progenies sampled in each of the F2:3, F3:4, F8:9, and F9:10 generations, resulting in 66 genotypes tested, considering the progenies along with the parents. These were evaluated in the field in a randomized block design with three replicates. The cooking time of the beans was measured 30 days after harvest using the Mattson cooker, with a temperature of 100°C, and the response variable was obtained in minutes until cooking was complete. The components of phenotypic variation were estimated according to the mixed model, with genotypic variation divided into additive and dominant components. The dominance genetic variance component was higher than the additive component. The estimates of dominance genetic variance were greater than expected for the cooking time trait in the segregating generations. The estimates of additive genetic variance and selection gains in advanced generations of self-fertilization were better when compared to the early generations. Despite this, the genotypic effects demonstrated the possibility of selecting for reduced cooking time in the early generations. However, genotype elimination is more effective at higher levels of homozygosity due to the reduction in dominance genetic variance and the increase in additive genetic variance.