硒肥对水稻生长及其重金属累积的影响

Effect of Selenium Fertilization on Rice Growth and Accumulation of Heavy Metals in Rice(Oryza sativa)

以大田水稻作为研究对象,分析了不同硒肥量对水稻生长特性及重金属(砷、铬、镉、铅)累积的影响,探讨了通过施硒降低重金属在水稻可食部分含量的可行性。结果发现:施用不同量硒肥(30、60和120 kg/hm2)对水稻分蘖数、株高、单株干物重和产量有促进作用,但差异不显著。施用120 kg/hm2硒肥显著增加了大米中的总硒、无机硒及有机硒的含量,并使有机硒比例增加了16.6%。施用120 kg/hm2硒肥有效抑制了水稻穗部铬和镉的累积量(53%和45%),而对铅无明显抑制作用。施用硒肥促进了硒向精米、糠中转移,同时有效降低了精米中镉、铬、铅的累积量。

A filed experiment was conducted to explore the effects of different Se fertilization rates on rice growth and the accumulation of heavy metals (As,Cr,Cd,Pb)in rice and to disclose the feasibility to reduce the contents of heavy metals in the edible part of rice by Se fertilization.The results showed that selenium fertilization increased rice plant tillering,height and dry matter weight,but no significant differences existed in different Se fertilization treatments (30,60,120kg/hm^2).Selenium fertilization had certain stimulation effect on rice yield.Selenium fertilization significantly improved the contents of total selenium,and inorganic and organic selenium in rice,which were increased by 300%,94% and 400%,respectively,among of which,the proportion of organic selenium increased from 68.6%to 85.2%.Selenium fertilization significantly increased the accumulation of Se and As in rice panicle by 260% and 85%,respectively,and significantly inhibited the accumulation of Cr an Cd by 53% and 45%,respectively.But there was no significant inhibitory effect on Pb (0.05%).So Se fertilization can promote Se be transported to millde rice and bran,and can inhibit As be transferred from the branches to husk and bran.At the same time, selenium fertilization can effectively inhibit the accumulation of Cr,Cd and Pb in milled rice.