Selection protocols for increased yield and stress tolerance in common bean

Abstract

Selection protocols are needed to assess yield potential and stress tolerance among diverse common bean (Phaseolus vulgaris L.) progenies derived from wide crosses. The objective of this study was to assess the value of using geometric means of stressed and non-stressed yield trials and deviations from regression of stressed yield regressed onto non-stressed yield to select for yield potential and stress tolerance among highly diverse common bean lines. Short single-row plots in multiple environments (stressed and non-stressed) were used for evaluation. Seed yield was measured for forty-eight diverse common bean lines grown in four field trials in Puerto Rico. Two trials were stressed with soil compaction, waterlogged soil, and a bean monoculture, whereas the other two trials (non-stressed) did not receive the above stress treatment. Geometric means were effective in differentiating the highest yielding lines across environments. Deviations from regression were effective in identifying lines with stress tolerance, but not necessarily so in identifying tolerant lines with yield potential. In many instances, selection based on geometric means and deviations from regression identified different lines. On the basis of the evaluation of these 48 diverse lines, geometric means of multiple environments (stress and nonstress) are recommended for the yield evaluation of highly diverse progenies from wide crosses.