Simultaneous selection for grain quality and mineral concentration in Mesoamerican common bean under drought stress

In a scenario of climate change, alterations in commercial grain quality traits and minerals are expected to occur in common bean genotypes cultivated under drought stress conditions. This study was undertaken to investigate the genetic variability of commercial grain quality traits and mineral concentration in Mesoamerican common bean genotypes cultivated under drought stress conditions, as well as to carry out simultaneous selection for multiple traits. The experiments were conducted during years with precipitation levels below the annual average due to the La Niña climate phenomenon. Twelve Mesoamerican common bean genotypes, comprising elite lines and cultivars from five breeders, were assessed for 11 commercial grain quality traits and the concentration of seven minerals. The standardized index ( index) was applied with the aim of simultaneously selecting for multiple traits. A significant genotype effect was detected for all traits, except for magnesium concentration. Thus, genetic variability was evident for most evaluated traits, enabling the selection of genotypes featuring high commercial grain quality and increased mineral concentration. However, when cultivation is carried out under conditions of prolonged water restriction, a reduction in mass of 100 grains is observed, while mineral concentration remains unchanged in the common bean genotypes. Line LEC 03-16 possesses the highest number of traits associated with high commercial quality in carioca grains, as well as the highest concentrations of potassium (≥ 11.95 g kg-1 dry mater - DM), phosphorus (≥ 4.71 g kg-1 DM), zinc (29.71 mg kg-1 DM), and copper (8.38 mg kg-1 DM). Cultivar IPR Urutau has high commercial quality of black grains, whereas cultivar BRS Esteio excels for the highest concentration of potassium (≥ 11.66 g kg-1 DM), phosphorus (≥ 3.88 g kg-1 DM), calcium (≥ 0.86 g kg-1 DM), iron (59.62 mg kg-1 DM), zinc (25.17 mg kg-1 DM), and copper (7.72 mg kg-1 DM). Line LEC 03-16 and cultivar BRS Esteio exhibit greater mineral concentration under drought stress, and their cultivation is promising for food and nutritional security.