有机酸对铬超富集植物李氏禾吸收Cu的影响

Effect of organic acids on the Cu uptake by Cr-hyperaccumulator:Leersia hexandra Swartz

许多研究表明有机酸的施加对植物吸收重金属的量具有不同的影响。文章采用盆栽试验研究了EDTA、柠檬酸、草酸和酒石酸对土壤中Cu的活化和李氏禾(Leersia hexandra Swartz)吸收Cu的影响。结果表明,当向土壤中施加质量摩尔浓度为2mmol·kg-1的EDTA时,土壤中Cu质量分数为220.16mg·kg-1与空白土壤中500.31mg·kg-1相比明显减少,说明EDTA可以极显著的降低土壤中的铜质量分数,使其转化成水提取态的Cu浮于土壤表面,并大部分聚集在根部周围,同时向土壤中施加EDTA不但促进了对Cu的活化而且显著提高了李氏禾对Cu的吸收,叶中最高质量分数达到336.54mg·kg-1是对照中80.34mg·kg-1的四倍;而柠檬酸、草酸和酒石酸则抑制了Cu的活化,但对李氏禾地上部分的Cu质量分数影响不大。有机酸对Cu的影响相对较弱,除EDTA显著降低了土壤中Cu质量分数外,其他有机酸对Cu的活化和李氏禾吸收Cu的影响与对照均没有明显差异。

Many research indicated that application of organic acids has the different influence to heavy metal uptake. The pot experiment was carried out to study the effect of different organic acids, EDTA, citric acid, oxalic acid and malic acid, on mobilization of Cu in soil and Cu uptake by Leersia hexandra Swartz. The results indicated that the concentration of Cu in the soil is 220.16 mg·kg^-1 contrast to the CK 500.31 mg·kg^-1 significantly decrease when the concentration of EDTA in the soil is 2 mmol·kg^-1 that explains EDTA treatment significantly decreased soluble Cu content in soil because of translating into Cu of water distill floating on the surface of soil and most accumulating around root.Contemporary, application of EDTA to the soil significantly enhanced mobili- zation of Cu in soil and increased Cu uptake in shoot of Leersia hexandra Swartz.,the highest concentration in the leaves 336.54 mg·kg^-1 is 4 times higher compared with the ck 80.34 mg·kg^-1. However, citric acid, oxalic acid and malic acid inhibited mobilization of Cu and less significantly affected shoot Cu accumulation. For organic acid, only EDTA treatment significantly decreased soluble Cu content in soil. Other organic acids treatment had little effect on soluble Cuand shoot Cu content compared with the control.