外源壳聚糖对苹果幼苗生长及抗旱性的影响

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

采用盆栽控水的方法研究了干旱条件下壳聚糖(chitosan)对苹果幼苗生长及抗旱性的影响。结果表明:在中度干旱条件下,叶面喷施壳聚糖能提高叶绿素含量和光合速率,增强碳素同化能力,促进游离氨基酸、可溶性糖和脯氨酸等有机渗透调节物质的积累,增强渗透调节能力。壳聚糖能维持或提高保护酶(SOD、CAT)活性,防止或降低细胞膜脂过氧化作用,由此维持正常代谢水平,促进植物的生长,提高抗旱性。壳聚糖对苹果幼苗生长及抗旱性的效应与浓度有关,一定浓度范围内,随壳聚糖浓度增加其效应增强,适宜浓度为100 mg.L-1,再增加浓度其作用效果不再增大。

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.