重金属胁迫条件下空心莲子草的生长和营养特征分析

空心莲子草是一种常见的水生植物,并能在重金属污染的水体或附近土壤中生长.本研究发现,空心莲子草能富集6种常见的重金属元素,其富集能力为:Zn2+>Mn2+>Pb2+>Cu2+>Cd2+>Cr3+.高浓度(1 mmol/L) Cu2+、Mn2+、Zn2+和Cr3+ 等重金属胁迫处理条件下,空心莲子草的根冠比增加,生物干重、总根长和总根表面积都相应降低.此外,高浓度(1 mmol/L) Pb2+、Cd2+、Cu2+或Zn2+分别胁迫处理条件下,空心莲子草的K+、Ca+和Mg+等元素的含量变化差异显著(P＜0.05).以上研究表明,空心莲子草通过改变体内钾钙镁等重要生长元素营养情况来适应重金属污染的胁迫,有很强的富集重金属元素的能力,进而降低污染、净化水体.空心莲子草对重金属污染的生长响应及体内重要矿物元素营养特性之间的相互关系,可能为重金属污染的水土生物修复提供理论依据.

Alternanthera philoxeroides Might Be Used for Bioremediating Heavy Metal Contaminated Soil

Alternanthera philoxeroides, usually called as Shui-hua-sheng in China and commonly known as Alligator weed in English, is an immersed aquatic plant and is listed an invasive species in China. In this work, we found that Shui-hua-sheng (A. philoxeroides) is able to accumulate six heavy metals with the ability of Zn2+>Mn2+>Pb2+>Cu2+>Cd2+>Cr3+. Under the conditions of the stimulated external high concentration (1 mmol/L) of Cu2+, Mn2+, Zn2+ and Cr3+, the biomass of Shui-hua-sheng (A. philoxeroides) reduced, total length of root and total area of root surface decreased as well, accordingly R/S ratios increased. Moreover, the nutriational characteristics of K+, Ca2+ and Mg2+ were altered significantly, respectively, under the exposure to contaminations of Pb2+, Cd2+, Cu2+ and Zn2+. The findings in this research implied that the Shui-hua-sheng (A. philoxeroides) be able to tolerate mentioned heavy-metals with high level contamination, and also might be as alternative to be used for biomediation of heavy-metal polluted soil or water.