模拟酸雨和Zn复合污染对蚕豆生长及其生理生化特性的影响

通过盆栽试验研究了模拟酸雨和Zn复合污染对蚕豆生长及其生理生化特性的影响．结果表明，与对照相比，在酸雨和Zn复合污染下，蚕豆株高和叶绿素均有不同程度的下降；蚕豆叶和根中的MDA含量上升，SOD活性下降，POD活性则是先升后降．MDA含量和SOD活性变化能较好地反映蚕豆受酸雨和Zn污染的状况．同时，酸雨和Zn的复合污染比其中任何一种单一污染对蚕豆造成的伤害更严重．

Complex effects of simulated acid rain and zinc on growth and physiological-biochemical characteristics of Vicia faba L.

Complex effects of simulated acid rain and Zn on the growth and physiological-biochemical characteristics of Vicia faba L. were studied with a pot experiment. Under the conditions of complex pollution with acid rain and Zn, the heights and the chlorophyll contents of Vicia faba L. decreased with increasing Zn concentrations, acid rain acidity or both. Each of them had no significant differences compared with the control blank case if Vicia faba L. received only simulated acid rain solutions. However, lower heights or chlorophyll contents could be observed in the cases of complex pollution with acid rain and Zn than any single pollution, especially when Vicia faba L. received more serious acid rain and higher Zn concentrations. It demonstrated that simulated acid rain made the more serious toxic effects of Zn on growth of the plants. Compared with the control experiment,when pHvalue of acid rain was 3.5 and the concentration of Zn was 200mg·kg^-1, the heights and the chlorophyll contents of Vicia faba L. decreased 45.5% and 41.8%, respectively. Generally, the contents of MDAin the roots and leaves of Vicia faba L. increased with increasing Zn concentrations and acid rain acidity. And contents of MDAin the roots were much higher than those in the leaves. It indicated that the changes of MDAcontents in Vicia faba L. could be used as a good index to reflect the pollution levels of acid rain and Zn. And the SODactivities in both leaf and root tissues of Vicia faba L. were usually declined with increasing the concentrations of Zn in soil and decreasing pHvalues by simulated acid rain. Meanwhile, the SODactivities in the root tissues decreased more rapidly than in the leaf, which indicated that the roots of the plant were more sensitive to the pollution with acid rain and/or Zn than the leaves. The PODactivities increased first and decreased afterwards. The fact that PODactivities in the root tissues were much greater than in the leaf showed that the protective enzymes in the roots eliminated most part of the free radicals brought from the pollution through intense reactions, and mitigated the pressure on the leaves. However, some roots and leaves became dying when treated with serious simulated acid rain and high Zn concentrations, which resulted in the PODactivities decline.