Divergência genética e seleção combinada para caracteres de sementes, agronômicos, tecnológicos e minerais em cultivares de feijão

Abstract

The bean culture holds great national importance; hence, the development of new cultivars with quality seed traits, agronomic, technological, and nutritional grain traits would serve as an additional tool to address food, economic, and social issues. Therefore, the objectives of this work were: (1) to assess whether common bean cultivars differ in seed quality, agronomic, technological, and mineral traits; (2) to study the correlations among these traits; (3) to analyze the genetic divergence among cultivars; and (4) to select cultivars with superior values for these traits. The experimental design employed was randomized complete blocks with three replications, consisting of 25 common bean cultivars. Experiments were conducted in the area of the Department of Crop Science at the Federal University of Santa Maria, in four cultivation environments: 2019 rainy, 2020 rainy, 2021 dry, and 2021 rainy season. The following traits were evaluated: six seed quality, 12 agronomic, and 16 technological and mineral concentration. Statistical analyses included individual and combined variance, Scott-Knott mean test, Pearson's linear correlation, principal components, Tocher's optimization method, average linkage clustering (UPGMA), and complete linkage (furthest neighbor). Selection indices, sum of ranks, and multiplicative were also employed. In the combined variance analysis, a significant cultivar × environment interaction was observed for most traits under study. Generally, intermediate to high magnitude correlation estimates were obtained for seed, agronomic, technological, and mineral traits. In the genetic divergence analysis, clustering methods were efficient in forming similar cultivar groups, with mass electrical conductivity and 100-grain mass being the most significant contributors to genetic divergence. For seed quality, the application of the multiplicative index proved effective for selecting superior cultivars (SCS 205 Riqueza, IPR Juriti, BRS Esplendor, IPR Tangará, and Fepagro 26). Cultivars superior in agronomic traits were IPR Uirapurú, IPR Tiziu, SCS 205 Riqueza, Fepagro 26, and BRS Campeiro, selected based on the sum of ranks index (assigning weight ten for grain yield, weight four for lodging, height of the first pod, height of the last pod, and epicotyl diameter; and weight one for other traits). For technological and nutritional quality, the multiplicative index was efficient in selecting cultivars with light-colored grains (Pérola, IPR Tangará, and IPR Juriti) and with dark-colored grains (BRS Expedito, BRS Valente, and IPR Tuiuiú), possessing desirable grain shades and quick cooking attributes.