两种典型粘土矿物对狐尾藻镉毒害效应的缓解作用

Alleviating effect of two clay minerals toward cadmium treated Myriophyllum verticillatum

本文以高等水生植物狐尾藻为研究对象,人工模拟条件下,分别比较了膨润土和海泡石对不同浓度Cd(Ⅱ)胁迫下狐尾藻生物量、叶绿素、可溶性蛋白以及丙二醛的影响.研究结果显示,Cd(Ⅱ)对狐尾藻的光合系统、膜系统以及蛋白质等均具有明显的破坏作用;膨润土和海泡石的加入在一定程度上能够通过吸附作用将Cd(Ⅱ)固定,进而有效地降低水环境中Cd(Ⅱ)的浓度,减轻Cd(Ⅱ)对叶绿体结构的破坏,降低植物的膜质过氧化反应.实验表明,Cd(Ⅱ)初始浓度在0—30 mg·L^(-1)内,海泡石对狐尾藻镉毒害的缓解作用要强于膨润土.

In this work,we attempted to alleviate the toxicity of Cd（Ⅱ） toward aquatic plant Myriophyllum verticillatum using clay minerals. In the aquatic systems containing both Cd（Ⅱ） and Myriophyllum verticillatum,the biomass,chlorophyll,soluble protein and malondialdehyde of Myriophyllum verticillatum with or without the addition of bentonite and sepiolite were examined. The results showed that Cd（Ⅱ） induceal significant damage to the photosynthetic systems,membrane systems,and proteins of Myriophyllum verticillatum. On the other hand,with the addition of bentonite and sepiolite,the concentration of Cd（Ⅱ） was evidently reduced through the adsorption onto the clay minerals. As a result,the damage of Cd（Ⅱ） toward the chloroplast and membrane peroxidation was alleviated. Our results also showed that sepiolite was more effective than bentonite in alleviating the toxicity effect of Cd（Ⅱ） toward Myriophyllum verticillatum.