Moaed Almeselmani
Wheat is necessary to ensure a stable food style everywhere in the world. During the past few years wheat production in Syria fluctuated enormously, one important reason was climate change and more precisely drought. A physiological approach can complement empirical breeding and can enhance the rate of yield improvement under drought condition by identification important physiological traits associated with drought tolerance. This investigation was carried out under field conditions in the 1st and 2nd settlement zone in Syria (under water limited condition) with some drought tolerant and susceptible durum wheat varieties. Membrane stability index, relative water content, chlorophyll content and chlorophyll fluorescence were measured at vegetative, anthesis and post anthesis stage. Our findings showed that all varieties were superior in all physiological parameters under study as grown in the 1st settlement zone compared with the 2nd zone at all growth stages. More reduction in all physiological characters was recorded in drought susceptible variety in bohouth, which showed also more reduction in yield and yield components. Drought tolerant variety in douma were more stable and showed better adaptation and comparatively better physiological performance and higher yield under drought stress condition. This study lays emphasis on the importance of these traits particularly for breeder for improving drought stress tolerance.