Effects of Water Stress on Photosynthetic Characteristics and Antioxidant Enzyme Activities of Jujube Leaves in Southern Xinjiang

The photosynthetic characteristics and antioxidant enzyme activities in jujube leaves were studied under different degrees of water stress in this paper. The results showed that the net photosynthetic rate(Pn),transpiration rate(Tr),stomata conductance(Gs) and intercellular CO2concentration(Ci) significantly decreased with increasing drought stress.Contrary to other treatments,the phenomenon of midday depression of photosynthesis disappeared under severe water stress.Meanwhile,the transpiration rate(Tr),stomata conductance(Gs) and intercellular CO2concentration(Ci) significantly increased and then decreased under water stress.In addition,the activities of superoxide dismutase(SOD),catalase(CAT) and malondialdehyde(MDA) contents increased continuously with the deepening of drought stress.The activities of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT) increased and then decreased.