复合重金属污染对矿区植物生理指标的影响

Effects of compound heavy metal pollution on the physiological indexes of plants in mining areas

为研究龙葵、野苜蓿、沙蒿3种金昌本土植物在重金属胁迫下生理指标的变化,以原生土(S1)作为空白对照,原生+尾矿(原生土和尾矿质量按1∶1混合,S2)作为实验组,进行盆栽实验.结果表明,S2条件下,龙葵、沙蒿的株高显著下降(P<0.05);龙葵的叶绿素含量、游离脯氨酸含量及过氧化氢酶活性均显著下降,丙二醛含量显著上升;野苜蓿的游离脯氨酸含量、可溶性蛋白含量、过氧化氢酶活性和丙二醛含量显著下降;沙蒿的叶绿素含量、游离脯氨酸含量、还原型谷胱甘肽含量显著下降.冗余分析表明土壤pH和阳离子交换量对植物生理指标有一定影响.通过模糊隶属函数法和坐标综合评定法进行综合评价,得出抗重金属性顺序为龙葵>野苜蓿>沙蒿.龙葵作为金昌市尾矿区土壤重金属修复植物潜力巨大.

In order to study the changes of physiological indicators of three native plants of Jinchang under heavy metal stress,a pot experiment was conducted with native soil(S1)as a blank control and native+tailings(mass ratio of 1:1 mixture of native soil and tailings mass,S2)as the experimental group.The results showed that under the S2 condition,the plant heights of S.nigrum and A.desertorum significantly decreased(P<0.05);the chlorophyll content,proline content and catalase activity of S.nigrum decreased significantly.The dialdehyde content increased significantly;the proline content,soluble protein content,catalase activity and malondialdehyde content of M.falcata decreased significantly;the chlorophyll content,proline content and glutathione content of A.desertorum significantly decreased.A redundancy analysis showed that soil pH and cation exchange capacity had a certain influence on plant physiological indicators.A membership function analysis and comprehensive coordinate method showed the heavy metal resistance of three plants was:S.nigrum>M.falcata>A.desertorum.S.nigrum had a great potential as a soil heavy metal remediation plant in the tailings area of Jinchang.