干旱胁迫对西克刺桐花芽分化的生理特性影响OA

In order to explore the physiological characteristics of drought stress-induced flower bud differentiation in Erythrina sykesii,the physiological response of E.sykesii to drought stress and its flowering induction characteristics were analyzed.The physiological indicators such as the contents of photosynthetic pigments,soluble sugar,malondialdehyde and endogenous hormones,and the activities of superoxide dismutase(SOD)and peroxidase(POD)in the leaves of 8-year-old E.sykesii under drought stress were determined.The results showed that the photosynthetic pigment and endogenous hormone contents and antioxidant enzyme activities in the leaves of E.sykesii exhibited a trend of first increasing and then decreasing with the increasing degree of drought stress.The contents of chlorophylls and carotenoids,starch,and soluble sugar,IAA,GA3 and ZR in the leaves reach their maximum values under mild drought stress.The SOD,POD,catalase(CAT)activities and soluble protein content reach their maximum values under moderate stress.The contents of malondialdehyde,ABA,and carbon nitrogen ratio all significantly elevated along with the increasing degree of drought stress.The above physiological indexes showed that the flowering rate of branches increased significantly under drought stress,of which the effect of the moderate stress was the most obvious.The results indicated that the plant cell damage could be alleviated by increasing ABA content and antioxidant enzyme activity,and the flower bud differentiation and flower formation rate of branches were promoted under moderate drought stress.