【摘要】 采用营养液培养法研究了Cd处理时间对有铁膜和无铁膜水稻根表吸附Cd及植株吸收Cd动态变化的影响.水稻根表铁膜由50mg.L-1Fe2+(Fe50)诱导形成.供试植株在含10μmol.L-1Cd的营养液中生长不同时间后收获.结果表明,随Cd处理时间的延长,无铁膜和有铁膜处理水稻根表DCB-Cd含量均为先增加后减少,Cd处理2h达到最高,之后逐渐下降并趋于稳定.根系和地上部Cd含量均持续上升,Cd处理8h前增加缓慢,8h后增加幅度加大.有铁膜水稻根系和地上部Cd含量增加幅度均低于无铁膜水稻.有铁膜处理DCB-Cd含量、根系和地上部Cd含量均低于无铁膜处理.表明铁膜不影响水稻各部分Cd含量随时间的变化趋势;不同Fe处理之间根系和地上部Cd含量的差异可能与根系含Fe量有关.更多还原

【Abstract】 In a water culture experiment, rice seedlings were grown in a nutrient solution containing 10 μmol Cd·L-1, and harvested after different durations of growth. Two treatments were installed, i.e., adding 50 mg Fe2+·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.更多还原