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采用土培盆栽实验研究了在不同外源硒(硒酸钠)梯度(0,1 mg·kg-1,5 mg·kg-1)与外源汞(硫酸汞)梯度(0,0.5 mg·kg-1,1 mg·kg-1)条件下,苗期水稻根与地上部分中硒与汞的分布特征。结果显示,外源硒抑制了苗期水稻根与苗对汞的吸收与积累,苗期水稻对汞的吸收随外源硒增加而呈现降低趋势,5 mg·kg-1是外源硒处理与无硒处理组相比水稻根部汞含量的下降最多,达到36.83%,并使水稻苗的汞含量维持在较低水平。而外源汞添加量1mg·kg-1时水稻苗中硒含量达到(58.16±0.17)mg·kg-1,是相应无汞添加组的20.12倍,说明外源汞添加在一定程度上促进了苗期水稻对硒的吸收与累积。整体而言,水稻苗中的硒-汞的吸收迁移具有一定的相互作用,尤其在水稻苗中的硒-汞富集系数存在显著负相关关系(r=0.48),其可能的机制是硒在水稻根部与汞结合形成硒-汞络合物从而抑制水稻地上部分对汞的吸收,这对于利用硒酸钠来降低苗期水稻地上部分对汞的累积提供了数据基础。
Pot experiments were conducted to study the effects of different concentrations of exogenous selenium (sodium selenate) gradient (0,1 mg · kg -1, 5 mg · kg -1) and exogenous mercury (mercury sulfate) gradient (0,0.5 mg · kg -1) kg -1, 1 mg · kg -1), the distribution characteristics of selenium and mercury in root and shoot of seedling. The results showed that exogenous selenium inhibited the absorption and accumulation of mercury in roots and shoots of rice at seedling stage, and the absorption of mercury decreased with the increase of exogenous selenium at seedling stage. Exogenous selenium treatment and 5 mg · kg- Compared with the non-selenium-treated group, the mercury content in rice root decreased the most, reaching 36.83%, and the mercury content in rice seedlings was kept at a low level. The content of selenium in rice seedlings reached (58.16 ± 0.17) mg · kg-1 at the dose of 1 mg · kg-1, which was 20.12 times of the corresponding mercury-free group, indicating that the addition of exogenous mercury promoted the growth of rice seedlings to a certain extent Absorption and accumulation of selenium in seedling rice. Overall, the absorption and transport of selenium and mercury in rice seedlings had some interactions, especially the selenium-mercury enrichment coefficient in rice seedlings (r = 0.48). The possible mechanism is selenium in The combination of the root of rice with mercury to form selenium-mercury complex and thus inhibit the uptake of mercury by the aerial part of paddy rice provided a data basis for the use of sodium selenate to reduce the accumulation of mercury in shoot aerial parts.