水培条件下油白菜对Pb、Cd吸收和转运的影响

采用水培实验和室内分析相结合的方法,研究了不同含量Pb、Cd单一和复合污染对金属Pb、Cd吸收和转运的影响。结果表明,Pb和Cd主要在油白菜的根部富集;Cd和Pb不同添加量与油白菜体内累积量之间呈显著正相关。复合污染处理中,油白菜地上部的转运系数BCFCd随外源Pb含量的增大而增加,而根部则相反,即BCFCd随外源Pb含量的增大而降低,说明外源Pb可以促进油白菜对Cd在叶片中的富集,但会抑制Cd在根中的富集;油白菜地上部的BCFPb随外源Cd含量的增大而降低,而根部则相反,即BCFPb随外源Cd含量的增大而增加,说明外源Cd可以促进油白菜对Pb在根中的富集,但会抑制Pb在叶片的富集,Cd对Pb的富集具有双重作用;高含量的Pb(≥500 mg/L)会促进油白菜根部的Cd向地上部转运,而高含量Cd会抑制油白菜根部的Pb向地上部转运,使得更多的Pb滞留在油白菜地下部。

Uptake and Transport of Exogenous Cd and Pb in Baby Bokchoi

The effects of different concentrations of cadmium(Cd),lead(Pb) and their combination on the uptake and transportation of Cd and Pb in plants were studied by means of water culture.The results showed that Pb and Cd mainly enriched in the baby bokchoi roots;the content of Cd and Pb in baby bokchoi had significant positive correlation with exogenous Cd and Pb concentrations(p<0.01).In the combined Pb-Cd treatment,the BCFCd of aerial part of baby bockchoi increased with the concentration of Pb in water culture,while BCFCd of root was the opposite,namely BCFCd of roots of baby bockchoi decreased with the concentration of Pb increased in water culture,indicated that exogenous Pb concentration can promote the enrichment of Cd in the leaves,but inhibited the enrichment of Cd in the roots;the BCFPb of aerial part of baby bockchoi decreased with the concentration of Cd in water culture,while BCFPb of roots was the opposite,namely BCFPb of roots of baby bockchoi increased with the concentration of Cd increasing in water culture,indicated that exogenous Cd concentration can promote the enrichment of Pb in the roots,but inhibited the enrichment of Pb in the leaves;Cd has a dual role in the Pb enrichment in baby bockchoi.The high concentration of Pb(≥500 mg/L) could promote the transfer of Cd from the root system of baby bockchoi to the aerial part,while Cd could inhibit the transfer of Pb from the the root system of baby bockchoi to the aerial part,which could keep more Pb in the roots of baby bockchoi.