复合重金属胁迫对灯心草生长及其积累特性的影响

盆栽试验结果表明：Cd、Pb、Cu、Zn、As5种重金属复合胁迫对灯心草地上部生长有一定程度的抑制作用，在土壤环境质量二级标准上限值处灯心草地上部生物量减产9．15％，小于10％，生长在矿毒水和铅锌尾矿污染土壤中的灯心草地上部生物量分别减产28．23％和37．1％，但地下部生物量减产趋势不明显。以地上部生物量为参考指标，可初步将土壤环境质量二级标准上限值拟设定为土壤中各重金属的临界毒性效应值。在Cd、Pb、Cu、Zn、As复合胁迫条件下，各重金属在灯心草茎叶和根系中的积累和分布存在明显差异，且与土壤中各重金属含量间存在一定的相关性。

Effect of Compound Stress of Heavy Metals on the Growth and Accumulation Characters of Juncus Effuses

In this paper,the effect of the compound stress of Cu,Cd,Pb,Zn and As on the growth and the accumulation and the distribution of heavy metals in Juncus Effuses is researched by using soil cultures method.The test results show when the dosage of the heavy metals added to the soil is close to the Grade II of National Environmental Quality Standard for Soil(GB15618-95),Juncus Effuses can grew normally in appearance and its yield decreases by less 10%,and the yield of biomass of Juncus Effuses on ground in the soil polluted by mine toxic water and in lead/zinc mining tailings deceases by 28.23% and 37.1% respectively,while the yield of biomass underground does not decrease in evidence.This may predict that Juncus Effuses could be regarded as a good application prospect in removing heavy metals from contaminated soil.The upper value of Grade II can be formulated as the eco-toxicological effect critical value of Cu,Cd,Pb, Zn and As in soil by means of reference index of biamass of Juncus Effuseson ground.Under the compound stress of above heavy metals,the accumulation and distribution of heavy metals in the shoot and root reveal the apparent differences with the content of heavy metals in soil.