Effects of Exogenous Abscisic Acid on Physiological Characteristics in Soybean Flowering under Drought Stress

Soybean Suinong 14were pot planted in greenhouse,and different drought stress were set at flowering,then 1.0~8. 0mg·L-1 Abscisic acid(ABA)were leaf sprayed and content of soluble protein contents,ascorbic acid contents and generation rate of superoxide anion radical in soybean blades under drought stress were determined 1~13days later.The results showed that compared with normal water irrigation,soluble protein contents,ascorbic acid contents and generation rate of superoxide anion radical in leaves under drought conditions increased.By spraying exogenous ABA soluble protein contents and ascorbic acid contents were enhanced more Obviously under drought stress.Exogenous ABA relieved the change of the three physiological indexes under drought stress.In the test,2.0mg·L-1 ABA obviously improved soluble protein contents;4.0mg·L-1 ABA significant alleviated the increase of ascorbic acid contents.Exogenous ABA relieved the increase of generation rate of superoxide anion radical in soybean blades under drought stress apparently.Above results indicated that a certain concentration of ABA could effectively enhance the antioxidant capacity.