Evaluation of common bean morphological traits identifies grain thickness directly correlated with cooking time

ABSTRACT The development of new common bean cultivars with grain characteristics that achieve greater acceptance by consumers and faster cooking time is a recent trend in bean breeding programs. This study aimed at evaluating whether different common bean lines exhibit differences in grain morphological traits and cooking time, investigating the linear relationships between these traits and cooking time, and selecting lines with superior grain commercial characteristics and faster cooking times. A randomized blocks design with three replications was used. Treatments consisted of 14 common bean genotypes grown during two seasons. Differences in the mass of 100 grains and grain length, width, thickness, shape, flatness, percentage of water uptake and cooking time were observed between lines. A high positive correlation was observed between grain thickness and cooking time (r = 0.9727). The path analysis revealed that grain thickness had the highest positive direct effect on cooking time (0.62). Therefore, fast-cooking common bean lines can be indirectly selected based on lower grain thicknesses. The DF 06-17 line presents fast-cooking grains with characteristics well accepted by the market and consumers.