احمد آقایی

Environmental stresses such as drought cause alterations in a wide range of physiological and biochemical processes in plants. In this research, the effect of drought stress on the contents of the photosynthetic pigments, chlorophyll a, b, total and carotenoids was evaluated in two genotypes of bread wheat under in vitro culture condition. Drought stress was induced by applying polyethylene glycol (PEG-6000) solutions using four concentrations (0, 2.5, 5, and 10%) in Murashige and Skoog (MS) medium. Cultures were kept under controlled conditions (16/8-h light/dark photoperiod and 25±1 ºC) during the experiment. The experiment was arranged in a completely randomized design with four replications, and chlorophyll a, b, and total as well as carotenoid contents in shoots samples were determined. Results showed that an increased concentration of PEG in the medium caused a decrease in the chlorophyll contents particularly in sensitive genotype. However, carotenoid contents were increased especially in tolerant genotype.