Common bean (Phaseolus vulgaris L.) originated in medium to high altitude regions and is sensitive to high temperatures. Climate changes from an increase in global temperatures are foreseen, and therefore better understanding of the mechanisms of heat tolerance is necessary. In this context, the aim of this study was to investigate the effects of heat stress on twelve common bean genotypes under natural growing conditions in three locations (Campinas, Votuporanga, and Ribeirão Preto, SP, Brazil) and in two growing seasons (fall-winter 2016 and summer 2016/2017). Data were analyzed by combined analysis of variance in a 2 × 3 × 12 factorial arrangement, considering two crop seasons, three locations, and twelve genotypes as factors. This was followed by the Scott-Knott mean comparison test (P<0.05), genetics, genetics×environment (GGE)-biplot analysis for grain yield and Pearson correlation for the summer season. Significant differences were found for the crop season, location, and genotype for most of the traits evaluated. It was found that the high temperatures, reached in summer, negatively affected the performance of cultivars, resulting in a reduction of 40% in grain yield. Votuporanga, which reached the highest temperatures during the summer, was considered as the most unfavorable environment. The genotypes that proved to be more productive in the summer for the locations of Campinas were BRS Agreste and FT Nobre; for Votuporanga, the genotypes Pérola and IPR Tangará; and for Ribeirão Preto, the genotypes SEA 5 and BRS Estilo. The highlighted correlations observed by the Pearson test were the highest leaf temperature reducing grain yield and, the highest relative index of chlorophyll contributed to higher productivity.

 

Key words: High temperature, Phaseolus vulgaris, selection, genotype × environment interaction, plant breeding.