铜与锌对香樟、广玉兰及榉树生理生化特性的复合影响

为了解土壤中铜（Cu）与锌（Zn）对不同乔木抗氧化系统的复合影响及植物生态修复土壤cu和Zn复合污染的生理生化基础，以香樟（Cinnamomumcamphora）、广玉兰（Magnolia grandiflora）和榉树（Zelkovaschneideriana）3种乔木为实验材料，采用土培盆栽方法，研究单-Cu2＋（75mg·L-1）溶液和单一Zn2＋（210mg·L-1）溶液及两者复合溶液污灌对香樟、广玉兰和榉树叶片丙二醛（MDA）含量、脯氨酸（Pro）含量、过氧化物酶（POD）活性和过氧化氢酶（CAT）活性的动态影响。结果表明，Zn2＋／t~用下3种乔木MDA含量升高，Cu2＋作用下MDA含量降低，Zn2＋和Cu2＋复合作用下3种乔木MDA含量低于Zn2＋作用，即210mg-L。Zn2＋对3种乔木生长的毒害作用比75mg·L。Cu2＋明显，两者复合作用使Zn2＋的伤害作用减轻。随胁迫时间延长，香樟POD和CAT活性增加，MDA含量和Pro含量减少。广玉兰细胞活性氧代谢失衡，POD活性和CAT活性急剧上升，第7天时分别达到1243．89％和300．00％（单一Cu2＋’）、149．22％和60．00％（单一Zn2＋）、653．96％和170．00％（Cu2＋和Zn2＋复合作用）。榉树无法承受高浓度Cu2＋和Zn2＋伤害而死亡。综合考虑，Zn2＋对3种乔木伤害严重，Cu2＋在诱导POD和CAT活性过程中与zn2＋存在拮抗作用，香樟对重金属Cu2＋和zn2＋的耐性最强。

Combined effects of copper,zinc on physiological and biochemical characteristics of Magnolia grandiflora,Cinnamomum camphora and Zelkova schneideriana

In order to tmderstand combined effects of copper （Cu） and zinc （Zn） in soil on antioxidative system of different trees, and explore the physiological-biochemical basis for the phytoremediation of Cu-Zn polluted soil, the dynamitic effects of single and combined solutions of Cu2＋ （75 mg.L1） and Zn2＋ （210 mg.L1） on the contents of malondialdehyde （MDA）, the activities of peroxidase （POD）, the activities of catalase （CAT） and the content of proline （Pro） in the leaves of Cinnamomum camphora, Magnolia grandiflora and Zelkova schneideriana planted in the pot with soil. The results indicated that compared with those of the control, the contents of MDA in three species of trees were increased in the treatment of Zn2＋, nevertheless were decreased in the treatment of Cu2＋. The contents of MDA in three species of trees in the combined treatment of Zn2＋ and Cu2＋ were lower than those in the treatment of Zn2＋. That is to say, the toxic effect of 210 mg＇L1 Zn2＋ on three species of trees was higher than that of 75 mg-L1 Cu2＋, and the combined treatment of Zn2＋ and Cu2＋ alleviated the toxic effect of Zn2＋ on these trees. In addition, as time goes, the activities of POD and CAT in Magnolia grandiflora increased, and the contents of MDA and Pro in Magnolia grandiflora decreased. Magnolia grandiflora lost its balance in the metabolism of H202, which led to the increase in the activities of POD and CAT, and the increase degrees on the 7th day were 1243.89% and 300.00% （single treatment of Cu2＋）, 149.22% and 60.00% （single treatment of Zn2＋）, 653.96% and 170.00% （combined treatment of Cu2＋ and Zn2＋）. Zelkova schneideriana could not stand the harm of Cu2＋ and Zn2＋ at the high concentration, and went to die. In conclusion, Zn2＋ stress showed the most serious damage on these three trees. Cu2＋ has an antagonistic effect on these three trees with Zn2＋ during the activation of POD and CAT induced by Cu2＋. Cinnamomum camphora has the better resistant to Cu2＋ and Zn2＋ than Magnolia grandiflora and Zelkova schneideriana.