叶面喷施硒硅复合溶胶抑制水稻砷积累效应研究

砷是一种毒性较强的类金属元素,稻米砷污染是近年来环境科学关注的难点和热点问题。为了控制稻米对砷的吸收积累,利用水热合成法制备了一系列浓度硒掺杂硅复合溶胶。采用盆栽和大田试验结合的方法,研究了硒掺杂纳米硅溶胶对水稻（Oryza sativa L.）砷吸收积累的影响。结果显示,叶面喷施硒掺杂纳米硅溶胶可以有效缓解水稻砷毒害,增加稻米硒含量,抑制稻米砷积累。盆栽试验结果表明：叶面喷施质量分数1%的硒掺杂纳米硅溶胶（1%Se-Si处理）后,水稻籽粒干质量比对照增加了43.8%,砷含量下降了46%,硒含量由对照的0.050 mg·kg-1增加到0.272 mg·kg-1。且与喷施亚硒酸钠相比（1%Se处理）,喷施硒掺杂纳米硅溶胶更有利于水稻生长,抑制稻米砷积累。与喷施硒质量分数1%的亚硒酸钠（1%Se处理）相比,喷施质量分数1%的硒掺杂纳米硅溶胶（1%Se-Si处理）后,水稻籽粒干质量增加了65.4%,砷含量下降了33.1%。大田试验结果也表明：叶面喷施硒硅复合溶胶可以显著抑制稻米砷积累,且随着硒掺杂量的增加,稻米砷含量显著降低、硒含量显著增加;硒的最佳掺杂量质量分数为0.5%,叶面喷施这种硒掺杂硅溶胶,稻米总砷质量分数由对照的0.25 mg·kg-1下降到0.14 mg·kg-1,稻米中硒的质量分数为0.26 mg·kg-1,符合富硒大米标准。砷污染稻田上,叶面喷施硒硅复合溶胶不仅使稻米砷含量达标,而且可以生产出富硒大米。因此,叶面喷施硒硅复合溶胶可能是治理稻米砷污染的新途径。

Foliar application of selenium-silicon sol reduced arsenic accumulation in rice

Arsenic is a non-threshold carcinogenic metalloid. It becomes a growing public concern on amelioration the As contamination in paddy soils and reduction the As transfer to rice in recent years. In order to reduce the accumulation of arsenic in rice （Oryza sativa L.）, a series of concentrations of selenium doped silica sols were prepared by hydrothermal synthesis method. The effects of foliar application of selenium-silica sols on the arsenic accumulation in rice were investigated with pot and field experiments. The results showed that foliar application of selenium doped silicon sol was effective in alleviating the arsenic toxicity to rice, increasing selenium content of rice, and inhibiting the accumulation of arsenic in rice. Comparing with the control in the pot experiments, 1%Se doped silica sol （1%Se-Si） foliar application increased the rice grain dry weight by 43.8%, while decreased the arsenic concentration in rice grain by 46% and increased Se concentration in rice grain from 0.050 mg·kg-1 to 0.272 mg·kg-1. Comparing with 1% sodium selenite foliar application （1%Se） in the pot experiments, the dry weight of rice grain increased by 65.4%, while the As concentration in rice grain decreased by 33.1% with 1% Se doped silica sol （1%Se-Si） treatment. Field experiment results showed that foliar application of selenium-silicon composite sol could significantly inhibit the accumulation of arsenic in rice. With the foliar application of selenium-silica composite sols, the arsenic concentration of rice grain decreased with the increasing doping amount of selenium added into the selenium-silica sols, while the selenium content increased significantly with the increasing doping amount of selenium. The optimal doping of selenium was 0.5%, foliar application of this kind of Se doped silica sol, the total arsenic concentration of rice decreased from 0.25 mg·kg-1 of control to 0.14 mg·kg-1, and the selenium concentration in rice grain was 0.26 mg·kg-1, which was accorded with the standard of selenium