Growth,Physiological and Biochemical Characteristics of Tamarix chinensis Seedlings under Salt-drought Intercross Stress

The growth,photosynthetic pigment content,activities of SOD,POD,and MDA content of three years old Tamarix chinensis under different salt-drought intercross stress were studied in order to clarify the effect of salt and drought stresses on the growth and physio-biochemical characteristics of T.chinensis seedling.The results showed that:(1)The influence of salt stress on growth was greater than drought stress,and the sensitivity of stem and leaf to salt and drought stress was higher than that of root system.The plant height,stem base diameter and dry matter of T.chinensis were all reduced with the salt stress intensified.(2)With the salt and drought stresses intensified,photosynthetic pigment content increased and then decreased,the major factor transformed from drought to salt stress.Under severe salt stress,the contents of chlorophyll a and b decreased significantly.(3)Under moderate drought stress,the activities of POD and SOD firstly increased and then decreased with the salt stress intensified.The oxidation resistance of SOD and POD weakened gradually with salt and drought stresses intensified.(4)Appropriate salt and drought stresses can weaken the content of MDA.However,the content of MDA was higher under severe drought and mild and moderate salt stress.The study indicated that T.chinensis can improve its stress resistance by adjusted self-growth and physiological and biochemical characteristics,and exhibited stronger drought and salt resistance.T.chinensis had tolerance to intercross salt-drought stress,and appropriate drought stress could increase the resistance of T.chinensis to salt stress.