施硒对小麦籽粒硒富集、转化及蛋白质与矿质元素含量的影响

为研究小麦对外源硒的吸收、转化规律及施硒效应，于2012-2013和2013-2014年冬小麦生长季，通过叶面喷施亚硒酸钠溶液，分析了田间施用硒肥后小麦产量变化、籽粒中硒的富集和转化特征，不同施硒量与施硒时期对硒利用率、籽粒粗蛋白和矿质元素含量的影响。结果表明，施硒对小麦籽粒产量和千粒重无显著影响；籽粒中总硒和有机硒含量随施硒量增加而增大，且有机硒占总硒的比例稳定在78.5%~82.1%之间，相同施硒量条件下，灌浆前期的施用效果好于孕穗期；灌浆前期喷施150 g hm^–2纯硒，籽粒中总硒含量可达3101 μg kg^-1。小麦对硒的利用率在3.3%~19.0%之间，随施硒量的增加而降低，相同施硒量下，硒利用率以灌浆前期喷施最大，孕穗期喷施最小。施硒提高了籽粒中粗蛋白含量，促进了磷、铁、锰、锌4种元素及降低了钠在籽粒中的累积，对钾、镁、铜的含量影响不显著。

Effects of Se Application on Se Accumulation and Transformation and Content of Gross Protein and Mineral Elements in Wheat Grain

The objectives of this study were to understand the characteristics of selenium (Se) accumulation and transformation from inorganic to organic form in wheat grain and the effects of exogenous Se on grain yield, quality and Se utilization. In the 2012–2013 and 2013–2014 winter wheat growing seasons, we carried out a field experiment with foliage spray of Se fertilizer (sodium selenite solution) in four Se levels and three spray timing treatments. The results showed that grain yield and thousand-grain weight of wheat received no significantly effect from Se foliage spray. In contrast, the total and organic Se contents in grain increased with increasing the exogenous Se level, with the proportion of organic Se to the total Se from 78.5% to 82.1%. Under the same Se application rate, spraying at early-filling stage resulted in larger Se accumulation in grain than spraying at booting stage. The maximum Se content in grain was 3101 μg kg^-1 in the treatment of Se 150 g ha^–1 sprayed at early-filling stage. The Se utilization rate in wheat ranged from 3.3% to 19.0%, showing a decrease trend with more exogenous Se applied. Se utilization rate was influenced by Se application timing, with the maximum rate at early-filling stage and the minimum rate at booting stage under the same Se application rate. Besides, grain quality of wheat was improved by exogenous Se application. The contents of gross protein and accumulations of P, Fe, Mn, and Zn elements increased and the absorption of Na decreased in grain. Application of Se fertilizer had no significant effect on the accumulations of K, Mg, and Cu elements in wheat grain.