Submitted to: Journal of Agronomy and Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/15/2006
Publication Date: 10/1/2006
Citation: Porch, T. 2006. Application of stress indices for heat tolerance screening of common bean. Journal of Agronomy and Crop Science. 192:390-394. Interpretive Summary: Common beans yield poorly under high temperature conditions. Thus, one important goal for improving bean production is to improve its tolerance to high temperature stress. Several indices have been developed for the evaluation of the response of plants to stress. The goal of this study was to determine if these indices could be used for evaluating bean varieties under heat stress. Three separate indices were tested on 14 bean varieties in three different environments in Puerto Rico. The results indicate that it was possible to identify superior varieties for heat tolerance based on the stress indices. These varieties showed good yield under both high temperature (stress) and lower temperature (non-stress) conditions. Selected varieties using these indices can be used in breeding programs for improving high temperature tolerance in common bean.
Technical Abstract: Common bean is adapted to relatively cool climatic conditions and temperatures of >30°C during the day or >20°C at night result in yield reduction. The long-term goal of breeding for heat tolerance is the development of germplasm with improved field level tolerance under variable temperature conditions. Using previously developed stress indices, this study presents results from high temperature screening of 14 genotypes in both the greenhouse and field in Puerto Rico. A total of three sets of paired trials were conducted in the field and in the greenhouse under high temperature (stress) and lower temperature (low-stress) conditions. The geometric mean (GM), stress tolerance index (STI), and stress susceptibility index (SSI) were used to evaluate the genotypic performance under stress and low-stress conditions. The results indicate that it was possible to identify superior genotypes for heat tolerance based on their stress indices. In this evaluation of heat tolerance, HTI (STI) and GM, although correlated, were the most effective stress indices for the selection of genotypes with good yield potential under stress and low-stress conditions.