[Dynamics of Cd adsorption on rice seedlings root surface with iron coating and Cd uptake by plant]

In a water culture experiment, rice seedlings were grown in a nutrient solution containing 10 micromol Cd x L(-1), and harvested after different durations of growth. Two treatments were installed, i. e. , adding 50 mg Fe2+ x L(-1) to induce the formation of iron coating on seedlings root surface (treatment Fe50), and the control. The study on the dynamics of the Cd adsorption on root surface and of the Cd uptake by plant showed that both in the treatment Fe50 and in the control, the amount of adsorbed Cd on root surface was the highest in the first 2 hours, decreased dramatically then and remained relatively stable thereafter, while the Cd concentrations in roots and shoots increased slowly within the first 8 hours and rapidly then. The increment of Cd concentrations in roots and shoots was smaller in treatment Fe50 than in the control, and the amounts of adsorbed and absorbed Cd also showed the same picture, suggesting that the iron coating on rice root surface had little effect on the dynamics of Cd content in different parts of rice seedlings, and the reduced Cd uptake in treatment Fe50 was probably relevant with the Fe concentration in roots.