ABSTRACT Developing fast-cooking, mineral-biofortified common bean lines represents an important innovation for breeding programs. Thus, this study was conducted to determine whether elite Mesoamerican common bean lines differ for cooking time and mineral concentration and to select fast-cooking, mineral- biofortified lines. The experiments were carried out in two growing seasons, in which 16 common bean genotypes were evaluated. Cooking time was determined using a Mattson cooker, and the minerals were analyzed by acid digestion. The resulting data were subjected to individual analysis of variance, combined analysis of variance, clustering by the Scott-Knott test, and selection index (multiplicative). There was a significant genotype × environment interaction effect for cooking time and the concentrations of potassium, iron, zinc and copper. Only the phosphorus concentration showed no genetic variability between the common bean lines. The ranking of the best common bean lines differed for all traits examined in the different environments, according to the Scott-Knott test. The use of the multiplicative selection index allows selecting superior common bean lines for all traits, namely, DF 07-11, DF 08-21, DF 08-20 and DF 08-28. These lines exhibit a very short cooking time (up to 15 min), high potassium concentration (> 12.00 g kg-1 of dry matter) and the highest mean values of micromineral concentration, and will thus be selected by the breeding program.

ABSTRACT The characterization of genetic divergence in common bean cultivars for various traits related to plant architecture and grain yield is unprecedented. This study proposes to determine whether common bean cultivars of different grain types differ for 12 traits of plant architecture and grain yield; examine the correlations between these traits; analyze the genetic divergence of these cultivars; and select superior cultivars for these traits. A total of 22 common bean cultivars with the grains types most produced in Brazil were evaluated in two growing seasons. Plant architecture was analyzed based on 12 traits, and grain yield was determined at maturity. Significant genotype and genotype × environment interaction effects were obtained, indicating the existence of genetic variability for all evaluated traits. Several plant architecture traits were correlated, but none was highly correlated with grain yield. Firstand second-internode lengths are more important in differentiating common bean cultivars. Principal component and Tocher’s analyses resulted in the formation of four and seven groups of cultivars, respectively. Both methods are efficient in analyzing genetic divergence; however, Tocher's method is more informative. Cultivars BRS Campeiro, SCS 205 - Riqueza, BRS Esteio, IAC Imperador and Guapo Brilhante have a high grain yield potential, but only BRS Campeiro, BRS Esteio and Guapo Brilhante have upright plant architecture.