铜污染对野艾蒿生长发育的胁迫及伤害

Coercion and damage of Cu pollution on Artemisia lavandulaefolia growth.

通过水培试验，研究了Cu污染对野艾蒿生长发育的胁迫伤害．试验设Cu浓度为2．5、5、10、20和40mg·L^-1，以植物生长指标及生理指标为测试指标，试验周期14d．结果表明，低浓度Cu处理（2．5mg·L^-1）对野艾蒿生长有促进作用，但随Cu浓度增高（5～40mg·L^-1）则产生抑制效应．各项生长指标均与Cu浓度呈极显著负相关，叶绿素含量也产生类似变化．几种光合色素对Cu的敏感性顺序为：叶绿素a〉叶绿素a＋b〉叶绿素b〉类胡萝卜素．叶细胞膜渗透性、O2^-·产生速率和丙二醛（MDA）含量在Cu浓度为2．5mg·L^-1时较对照略有下降，再随Cu浓度升高而不断上升．POD、SOD和CAT活性随Cu浓度升高先上升，后下降，与根系耐性指数变化一致．在Cu浓度不超过20mg·L^-1情况下，根系耐性指数〉0．5；Cu浓度为40mg·L^-1时，根系耐性指数降低为0．36．

By the method of solution culture, this paper studied the coercion and damage of Cu pollution on the growth of Artemisia lavandulaefolia. The Cu concentration was set as 2.5,5, 10, 20 and 40 mg · L ^-1, experimental duration was 14 days, and the growth and physiological indices of plants were tested. The results showed that the growth of A. lavandulaefolia was stimulated at low Cu concentration （2. 5 mg · L^-1 ）, while inhibited at higher Cu concentrations （5 -40 mg · L^-1）. There was a significant negative correlation between each growth index and Cu concentration, and pigments contents had the similar trend. The sensibility of various photosynthetic pigments to Cu was in the order of chlorophyll a 〉 chlorophyll a ＋ b 〉 chlorophyll b 〉 carotenoid. Cell membrane permeability, O2^-· generation rate, and MDA content decreased slighdy at 2.5 mg Cu · L^-1 , and then increased with increasing Cu concentration. The activities of POD, SOD and CAT increased first but decreased then with the increasing Cu concentration, and the endurance index of root showed the same trend, being 〉 0. 5 at the Cu concentration less than 20 mg · L^-1 while decreased to 0. 36 at 40 mg Cu · L^-1.