Response of <i>Phaseolus vulgaris</i> L. cultivars under induced conditions of heat stress

Abstract

The production of common bean (Phaseolus vulgaris L.) is limited by diverse stressful conditions, amongst them high temperatures. Therefore, obtaining tolerant bean cultivars without affecting their yield is a purpose of the breeding programs of this important legume. Evaluation of physiological variables to determine the response of cultivars of P. vulgaris under heat stress can be a significant contribution to the identification of tolerant cultivars. This work was performed in order to determine the response of ten P. vulgaris cultivars under induced heat stress conditions. The effect of temperature on electrolytes leakage and release of inorganic phosphate in leaf tissue of P. vulgaris was determinate. In all tested temperatures (35-60 ° C), there was an increase at electrolytes leakage, regarding the value of this variable at 25 ° C for 10 cultivars under study.Significant differences of electrolytes leakage between cultivars were presented in the treatments where leaf tissue was exposed to 35 and 40 ° C.Different responses of the release of inorganic phosphate were observed depending on cultivars. ʹICA Pijaoʹ and ʹCuba Cueto 25-9 Blackʹ cultivars released the biggest amount of inorganic phosphate without differences between them.The temperature influenced on the leakage of electrolytes and the release of inorganic phosphate from the leaf tissue, and allowed us to determine the response of various cultivars under induced heat stress conditions. Key words: bean, electrolytes leakage, high temperatures, phosphate release, stressful conditions