Determination of combining ability and heritability for canning quality traits in common bean

Breeding for common bean (Phaseolus vulgaris L.) genotypes with optimal canning quality holds the potential for increased dry bean consumption among middle-class income urban dwellers in sub-Saharan Africa (SSA). Understanding the genetic control of canning quality traits is central for the improvement of common bean genotypes for desired canning quality. The objective of this study was to determine the combining ability and heritability of canning quality traits (CQTs) in common bean; and to establish entry points for effective breeding for these traits. A population from two contrasting parents for canning quality traits was developed and progressed to F2. The F2:F4 seed was evaluated for CQTs at three months post-harvest. Substantial variation was observed among the canning quality traits tested, including the general appearance of the canned beans, seed coat colour retention namely, clumping, free starch, splitting, and hydration coefficient. Canning quality traits encompassed a spectrum of both additive and non-additive effects. Promising combiners for CQTs were identified among the parents, KK8 and MAC 13, suggesting their potential for utilisation in breeding programmes. Moderate to high Baker’s ratio (BR = 0.41-0.94) values were observed for some CQTs and narrow sense heritability (h2 = 0.47-0.66). Canning quality traits exhibited substantial broad sense heritability (H2) values, ranging from 0.6 to 0.92. These findings provide valuable entry points for breeding programmes focused on improving common bean for canning quality.