Effects of Water Stress on Physiological Characteristics and Yield of Rice

[Objective]The research aimed to confirm suitable water saving irrigation indices for the production of rice.[Method]The effects of water treatment on physiological characteristics such as grain yield,grain water content during productive phase,leaf to spikelet ratio,protective enzyme activity of rice were investigated through cultivation experiment with rain-proof shelter,with soil water potential as the mininum irrigation control index.[Result]When low soil water potential was below-30 kPa,the relative values of leaf to spikelet ratio and grain water content showed negative effects during the 15-35 days after flowering,the relative values of activities of superoxide dismutase(SOD),catalase(CAT) and peroxidase(POD) in leaves increased significantly.The relative values of the activities of SOD,CAT,POD in leaves increased and then decreased after rewatering to saturated soil under optimal water stress(the soil water potential was higher than-30 kPa).[Conclusion]Different water stress had different effects on leaf to spikelet ratio and grain water content during grain-filling period.