氯离子和乙二胺四乙酸对镉的植物有效性的影响

通过水培试验，向营养液中添加不同浓度的Cl^-或乙二胺四乙酸（EDTA），研究了离子的配合作用对水稻及油菜吸收镉的影响.结果表明，随着营养液中Cl^-或EDTA浓度的增加，水稻和油菜地上部与根中镉的浓度降低.Cl^-浓度的增加抑制了水稻对镉的吸收，地上部与根部的镉含量分别从212.2和345.1 mg·kg^-1降低到34.1和209.1 mg·kg^-1.EDTA的添加抑制了水稻及油菜对镉的吸收，水稻地上部与根部的镉含量分别从212.2和345.2 mg·kg^-1降低到50.0和4.2 mg·kg^-1；油菜地上部与根部的镉含量分别从86.7和149.2 mg·kg^-1降低到22.2和12.3 mg·kg^-1.在营养液培养条件下，Cl^-或EDTA与镉的配合作用降低了植物对镉的吸收，与Cl^-相比，EDTA的抑制作用更明显.

Effects of chlorine ion and EDTA on cadmium availability to plants

In a water culture experiment with rice and rape, different concentrations of chloride or EDTA were added to study the effects of chlorine ion and EDTA complexation on the uptake of cadmium by the plants. The results showed that the cadmium concentration in the shoots and roots of test plants decreased with increasing concentration of chloride or EDTA. With the increase of Cl- concentration, the cadmium content in rice shoot and root decreased from 212.2 mg x kg (-1) and 345. 1 mg x kg - to 34.1 mg x kg(-1) and 209.1 mg x kg(-1) , respectively. EDTA addition decreased the cadmium content in rice shoot and root from 212.2 mg x kg (-1) and 345.2 mg x kg(-1) to 50.0 mg x kg(-1) and 4.2 mg x kg(-1) , and that in rape shoot and root from 86.7 mg x kg(-1) and 149. 2 mg x kg(-1) to 22.2 mg x kg (-1) and 12. 3 mg x kg(-1 ), respectively. EDTA also affected the cadmium translocation from root to shoot. The complexation of Cl- or EDTA with cadmium reduced the uptake of Cd by plants, and the effect of EDTA was more obvious than that of Cl -.