The effect of soil drought on the leaf gas exchange parameters and water relations in young bean plants (Phaseolus vulgaris L.) – cv. Abritus and cv. Dobrudjanski 7 were studied. Drought conditions were imposed on 2-week old plants by withholding water for 10 days. It was found that drought stress significantly decreased the net photosynthetic rate and transpiration. WUE in stressed plants of cv. Abritus remained unchanged, while in cv. Dobrudjanski 7 WUE was significantly increased. The water relation parameters were also affected. The changes were similar in the studied cultivars. In cv. Dobrudjanski 7 T was decreased more than twice, while in cv. Abritus T was decreased by 40 %. On the basis of the experimental outcomes, it was established that the cultivar reaction to drought was identical, but some differences were observed as well. In cv. Dobrudjanski 7 E and gs were decreased to a greater extent than A, and WUE was significantly higher. In cv. Abritus A was decreased to a greater extent than E and gs, nd WUE was slightly reduced. The leaf water potential (Ψw) is a parameter of water relations, which was reduced more than fourfold.
Effect of soil drought on leaf gas exchange and water relations in young bean plant (Phaseolus Vulgaris L.)