[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 -.