Effects of Exogenous Chitosan on Growth and Drought Resistance of Apple Seedlings

Effects of exogenous chitosan on growth and drought resistance of the apple seedlings studied under water stress was studied using pot-culture experiments simulating soil drought status).The results showed that Treated with exogenous chitosan can raise content of chlorophyll and photosynthetic rate and water use efficiency(WUE),and increase content of organic osmotica(Pro,amino acid and sugars) under middle level drought condition.The activity of SOD and CAT decreased and relative permeability of plasma membrane and content of MDA increased under water stress,but treated with exogenous chitosan gave rise to increasing of SOD and CAT activity and decreasing of MDA content and membrane lipid peroxidation under water stress.This indicated that under water stress chitosan can improve photosynthetic function and maintain normal metabolism and promote growth and enhance drought resistace of the apple seedings.