Variety traits

Heat tolerance of common bean

Phaseolus vulgaris L.

The ability of common bean to maintain pollen fertility and productivity at temperatures above 32 °C. A critical factor is sensitivity to heat stress during reproductive stages, causing flower abscission and underdeveloped seeds.

In the reference 4 varieties crop Common bean, where this is mentioned in the description.

The evaluation of heat tolerance in common bean is based on physiological indicators, including pollen viability, leaf water potential, and stomatal conductance under simulated heat stress. The JIP-test is used for the analysis of the photosynthetic apparatus, and the level of stress load is determined by the content of free proline. Under laboratory conditions, the potential of genotypes is assessed through seed germination rates at temperatures of 33–40 °C, while in field conditions, it is evaluated by the number and mass of pods.

High temperatures, especially during the flowering period, provoke mass bud abscission, and at the seed formation stage, they cause wrinkling and size reduction. Increased nighttime temperatures often have a more negative impact on yield than daytime maxima. In breeding, interspecific hybridization with tepary bean (Phaseolus acutifolius) is used to improve this trait, as the target indicator is defined as the ability to maintain pollen fertility when temperatures exceed the standard threshold by 3–4 °C.

General information about the subject — on the page Heat tolerance.

Sources8

Varieties of Common bean mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.