根表铁氧化物和缺铁根分泌物对水稻吸收镉的影响

在人工光照植物培养室中采用营养液培养方法，研究了不同镉浓度条件下，水稻根表沉积的铁氧化物及缺铁根分泌物对水稻吸收镉的影响。结果表明：（１）水稻根只的铁氧化物对其生长介质的镉有富集作用，并在一定程度上能促进水稻对镉的吸收。水稻生长的铁营养状况不同，则地上部镉含量不同，地上部镉含量达到最大峰值时根表铁氧化物的数量也不同。（２）当根表铁氧化物数量一定时，随着营养液中镉浓度的增大（镉的处理浓度为０、０．０

EFFECTS OF IRON OXIDES AND ROOT EXUDATES ON CADMIUM UPTAKE BY RICE

Solution culture is conducted to investigate the effects of iron oxides and root exudates on cadmium uptake by rice. The results showed that iron oxides may absorb cadmium from nutrient solution. The amount of Cd accumulated on rice root surface increased with the increase in amount of deposited iron oxides. Therefore, iron plaque can influence the Cd uptake. When Fe nutritional status of rice are different, the effect of iron oxides on Cd uptake by the rice roots is also different. Generally, with the increase of Cd concentration in medium, the amount of Cd deposited on root surface and Cd content in rice shoot increased. Rice root exudates (PS) may mobilize Cd accumulated by iron oxides on the surface of rice root and significantly enhance Cd uptake in the rhizosphere. When Cd concentration in nutrient solution was different, the effect of PS on Cd uptake was also different.