EDDS对铅镉污染的高羊茅和红三叶的影响

Effects of EDDS on Tall Fescue and Red Clover Contaminated by Lead and Cadmium

本研究利用盆栽试验研究Cd、Pb以及外加EDDS对高羊茅和红三叶生长及富集Cd、Pb能力的影响,测定植物干质量、植株体内重金属质量分数及叶绿素质量分数,旨在为Cd、Pb污染土壤的植物修复筛选适宜物种。结果表明,Pb、Cd污染使高羊茅和红三叶的生物量降低,添加EDDS使在经Cd100 mg.kg-1、Pb500 mg.kg-1处理的土壤中生长的高羊茅和红三叶地上部干质量均比对照略有升高,但差异不显著;高羊茅和红三叶可以富集土壤中的Pb、Cd,而且根部Pb、Cd的质量分数远大于地上部的,多数处理中EDDS可以增加根部Pb、Cd的富集量;外加EDDS使经Cd100 mg.kg-1处理的土壤中高羊茅和红三叶的叶绿素a/b的值有所升高,其他处理的叶绿素a/b的值都降低,但差异不显著。

The research was conducted to investigate the effect of Pd, Cd and EDDS on the growth and Pd/Cd hyper-accumula- tion ability of tall fescue and red clover by the pot experiments. The dry quality and the contents of heavy metals and chlo- rophyll in plant were determined to filter suitable plant species for the phytoremediation of Cd and Pb contaminated soil. The results showed Pd and Cd can decrease the net weight of tall fescne and red clover. The dry weight of tall fescue and red clover increase slightly compared with the control in soils with 500 mg·kg-1 Pb and 100 mg·kg-1 Cd by adding EDDS, but the variances are not significant. Tall fescue and red clover can be enriched by Pb and Cd in the soil, and the content in the roots is much larger than that above ground. EDDS can enhance the accumulation of Pb and Cd by the ma- jority treatments. The chlorophyll a/b ratios increase in the soil with 100 mg·kg-1 Cd by adding EDDS. However, the chlorophyll a/b ratios decrease by other treatments, but the variances are not significant.