EDTA对铅污染土壤上芥菜生长及铅积累特性的影响

采用盆栽实验研究了EDTA对Pb污染土壤上芥菜生长及Pb积累特性的影响。结果表明,单独Pb处理对芥菜生物量没有明显的影响,但高Pb处理(2000mg kg-1 Pb)芥菜地上部含水量显著降低;Pb处理芥菜体内Pb含量随土壤Pb浓度的增加而明显增加,根系Pb含量高于地上部Pb含量;3mmol kg-1 EDTA处理能促进土壤Pb溶解,增加土壤有效Pb含量,影响芥菜的正常生长,芥菜地上部生物量下降,高Pb浓度处理比低Pb浓度处理更明显;EDTA处理14天芥菜地上部和根系Pb积累量都比不加EDTA的对照明显增加,地上部Pb总量增加到对照的13.1～80倍;EDTA处理芥菜地上部与根系Pb含量的比值上升,表明EDTA处理促进Pb向地上部运输,这种促进作用因土壤Pb浓度的不同而略有差异。

Influence of EDTA Application on the Growth and Lead Accumulation of Mustard Seedlings Planted in Pb-contaminated Soils.

The pot experiment was conducted to investigate the influence of EDTA application on the growth and Pb accumulation of mustard seedlings planted in Pb-contaminated soils.The results indicated that different Pb concentration did not significantly change the biomass of mustard seedlings,however,shoot water content decreased remarkably under 2000mg kg-1Pb treatment.Pb contents in both shoots and roots of mustard seedlings increased with Pb concentration in soils,and Pb contents in roots was higher than that of in shoots.Application of 3mmol kg-1 EDTA to the Pb contaminated soils enhanced the available Pb concention,affected the seedling growth and decreased the shoot biomass.Pb conents in the shoots and roots of mustard seedlings were increased by treatment with EDTA,and shoot total Pb accumulation in mustard seedlings by EDTA treatment were 13.1-80 times higher than the controls without EDTA application.At the same time,the ratio of Pb contents in shoots and roots increased by EDTA treatment,which indicated that EDTA treatment improved the Pb transportation to the shoots.