| Abstract: | Heat susceptibility is a cause of yield loss in common bean (Phaseolus vulgaris L.) in temperate and tropical lowland growing regions. Interspecific hybridization with related species that include tepary bean (Phaseolus acutifolius A. Gray) can potentially be used to transfer heat tolerance traits to common bean. This study evaluated 25 tepary bean plant introductions (PIs) following exposure to high-temperature (35 °C day/32 °C night) and control temperature (27 °C day/24 °C night) during reproductive development. These 25 PIs were selected for high yield potential in a 14 h photoperiod greenhouse environment. High temperature when compared to non-stress treatment resulted in a mean reduction in seed yield of 88.8% among tepary beans and caused 100% yield loss in common beans. Twelve P. acutifolius PIs exhibited negligible yield under heat-stress when compared to control treatment. Although yields of these accessions were low under very high-temperature conditions, PI 200902, PI 312637, PI 440785, PI 440788, and PI 440789 exhibited the highest yield component stability under the high temperature treatment. |
