Relationship Between Some Physiological and Biochemical Characteristics and Drought Tolerance at Rice Flowering Stage

【Objective】Rice may suffer serious water stress duringtheir growth period,which affects the process of physiological metabolic activitys.So scientists studied physiological and biochemical characteristics of drought tolerance in rice..【Method】Ten rice cultivars with different drought tolerances were used as experimental materials.Changes in ascorbic acid(Vc) content,free amino acid content,soluble protein content,malondialdehyde(MDA) content and antioxidative enzyme activities were studied under both irrigation and drought conditions at the flowering stage.【Result】 The results indicated that water stress increased contents of Vc,free amino acid,soluble protein and malondialdehyde(MDA),as well as the activities of superoxide dismutase(SOD),catalase(CAT) and peroxidase(POD) in leaves at the flowering stage.Correlation analysis showed that the drought tolerant coefficient significantly or very significantly correlated with relative contents of Vc,free amino acid,MDA and SOD activity under both irrigation and drought conditions.【Conclusion】Therefore,they could be selected as identification indexes for drought tolerance at flowering stage.Using stepwise regression equation to evaluate the drought tolerance of rice cultivars was considered scientifically reliable.