芦荟对土壤中重金属的吸收及EDTA影响

Accumulation of Heavy Metals and Role of EDTA in Aloe vera L.

采用芦荟(Aloe vera L.)盆栽实验,考察了土壤中重金属在芦荟中的分布及施加EDTA对重金属在芦荟中积累影响。由实验结果,芦荟中重金属随土壤中重金属含量的增加而增加,Cd、Cu和Zn的增加量主要积累在叶部,而Pb的增加量主要积累在茎和根部。土壤中Pb的加入促进了芦荟对Cd和Cu的吸收,表明Pb与Cd、Cu在芦荟吸收时具有协同效应。随着土壤中EDTA用量的增加(0～4 mmol/kg),芦荟对重金属的吸收积累增加,其中Cu和Pb的增加较大。在EDTA作用下,芦荟叶部对重金属的迁移增大,其迁移系数Zn>Cd>Cu>Pb。EDTA螯合作用促使芦荟对重金属的吸收。芦荟叶部重金属对Fe的积累有明显抑制作用,而芦荟各部位中重金属对Ca的积累皆有明显抑制作用。

Distribution and effects of EDTA on accumulation of heavy metals （HM） in aloe （Aloe vera L.） were investigated by pot experiments. Results showed that HM concentrations in aloe increased with the increase of HM concentrations in soil, especially in leaves for Cd, Cu and Zn and in stems and roots for Pb. Addition of Pb to soil enhanced the concentrations of Cd and Cu in aloe, which indicated the synergistic effect of Pb and Cd, Cu. With the increase of EDTA concentration of 0-4 mmol/kg, HM concentrations in aloe increased. Translocation of HM increased due to effects of EDTA, and sequence of translocation factor is Zn, Cd, Cu and Pb. Chelating effects promoted the accumulation of HM in aloe. Accumulation of Fe in leaves of aloe was inhibited by HM, and Ca accumulation in leaves stems and roots of aloe were all inhibited by HM.