供氮水平对稻株铁、锰、铜、锌含量和稻米品质的影响

采用室内盆栽试验，研究了不同氮肥施用量对水稻铁、锰、铜、锌含量和稻米品质的影响。 随着氮肥使用量的增加，与对照相比，4种微量元素在稻株地上部组织中的含量增加。施氮水平对两个品种徽量元素含量的总体影响趋势一致，只是在稻株中含量不同，表明施氮量对品种的特性表达没有影响。糙米中微量元素含量随着施氮量的增加表现出先升高后降低的趋势，其中以氮肥使用量在160 kg/hm2时增幅最大。此时，IR64的糙米中的铁、锰、铜、锌含量分别比对照增加28.96%、41.34%、58.31%和16.0%，而IR68144的糙米铁、锰、铜、锌含量分别比对照增加2216%、13.75%、8.75%和2021%。同时，随着氮肥使用量的增加，籽粒蛋白质含量增加，直链淀粉含量降低，糙米的胶稠度变大。说明合理的氮肥管理措施可在一定程度上调控籽粒微量元素积累，改善稻米营养品质。

Effects of Different Nitrogen Fertilizer Levels on Concentrations of Fe, Mn, Cu and Zn and Grain Quality in Rice (Oryza sativa)

In a pot experiment at greenhouse, effects of N fertilizer on concentrations of Fe, Mn, Cu and Zn in shoot of rice and quality of brown rice were studied. With the increase of N fertilizer application, the concentrations of Fe, Mn, Cu and Zn in shoot increased. Effects of N fertilizer on IR68144 were similar to IR64, but different in the contents of trace elements in plant, suggesting that characteristic expression of the tested two genotypes is not controlled by the amount of N fertilizer supplied. Concentrations of those microelements in brown rice increased at first and then decreased with the increase of N fertilizer application. Contents of Fe, Mn, Cu and Zn in brown rice of the two varieties reached the highest level at 160 kg/hm^2 N. Comparing with control, contents of Fe, Mn, Cu and gn in brown rice of IR64 increased by 28.96%, 41.34%, 58.31% and 16.0%, while those of IR68144 increased by 22.16%, 13.75%, 8.75% and 20.21%, respectively. Meanwhile, N fertilizer Promoted the accumulation of protein in grains, decreased the accumulation of amylose, and enhanced gel consistency of brown rice. Those results indicated that appropriate N fertilizer management could increase micronutrient content in grains and improve nutrition quality of rice.