Effects Of Exogenous Selenium Fertilizer On Yield,Quality Formation And Selenium Accumulation Of Wheat

In order to explore the suitable application technology of selenium fertilizer for wheat in Shanxi Province,a comparative screening study of Inorganic Selenium Fertilizer,organic selenium fertilizer,Nano Selenium Fertilizer and standard selenium fertilizer was carried out in the Shanxi Agricultural University of Taigu from 2017 to 2018,a field experiment was conducted in 2018-2019 to study the application technology of selenium fertilizer in the Hongtong County Shanxi Agricultural University wheat experimental and demonstration base.The effects of different concentrations of 0 g·ha^-1、5 g·ha^-1、10 g·ha^-1、g·ha^-1 and 20 g·ha^-1 on the growth,yield,quality and grain selenium accumulation of wheat were studied,the main results are as follows:（1）Spraying four kinds of selenium fertilizer（inorganic selenium,organic selenium,nano-selenium,standard selenium）at anthesis stage could improve the dry matter quality,yield and grain selenium content of wheat at mature stage.Compared with Inorganic Selenium,organic selenium and nano-selenium,foliar application of standard selenium fertilizer increased dry matter accumulation by 1%-4%,increased yield by 2%-4% by increasing 1000-grain weight,increased the harvest index,increased the selenium content and its accumulation in grains by 8%-26%,11%-31%,and increased the organic selenium content and its ratio by 13%-39%,4%^-17%,to increase the content of selenomethionine and selenocystine organic selenium in grains.（2）At heading stage,anthesis stage and early filling stage,spraying Standard Selenium fertilizer improved the physiological activity and growth characteristics of flag leaf after anthesis,promote yield formation,increase yield and improve grain nutritional quality,but reduce the quality of some processed products,and improve the accumulation and utilization of selenium in grains,reducing the content of heavy metals in grains.Compared with heading stage and early filling stage,spraying standard selenium fertilizer at anthesis stage increased the activity of relative leaf green content（SPAD）,peroxidase of catalase and ascorbic acid,and decreased the content of MDA,increased the content of soluble protein in flag leaf and grain,increased the filling rate of wheat,increased the dry matter accumulation of plant,increased the number of grains per spike,1000-grain weight and yield,increased the content of protein in grain and the yield of protein,the contents of soluble sugar,sucrose and starch were increased,but the quality of dough and the properties of starch were decreased,and the selenium content,selenium accumulation,selenium utilization ratio and strengthening index were increased,reducing the content of Cr,Cd and Pb in grain.In addition,the grain protein content and soluble sugar,sucrose and starch content increased after spraying se fertilizer,but the difference was not significant.（3）Compared with other concentrations,spraying 15 g·ha^-1 selenium at anthesis increased the relative leaf green content（SPAD）,increased the activity of Catalase and ascorbic acid Peroxidase,decreased the content of MDA,and increased the rate of grain filling.It promoted dry matter accumulation,increased the number and proportion of bootable spikelets,increased grain number per spike and 1000-grain weight,increased yield by 2%^-10%,but not significantly.（4）Compared with other concentrations,the content of protein and its components,protein content and protein yield of grains sprayed with g·ha^-1 selenium solution at anthesis stage were the highest,but there was no significant difference with 10 g·ha^-1 treatment.The content of soluble sugar,sucrose and starch was the highest in 15 g·ha^-1 treatment,but the difference was not significant in other treatments.Compared with the control,the gluten content,dough formation time,stability time and FQN farinaceous curve quality index,Starch Peak viscosity,retention viscosity,dilute value,final viscosity and rebound value of wheat after spraying se fertilizer were lower,but the difference was not significant.（5）Compared with other concentrations,spraying 15 g·ha^-1 solution at anthesis increased the content of se in grains by 1%-25%,but there was no significant difference between spraying 15 g·ha^-1 solution and 20 g·ha^-1 solution,significantly increased the accumulation of se in grains by 4%-37%,and the utilization of se in grains by 0.5%-48%,but there was no significant difference with 10 g·ha^-1 and 20g·ha^-1treatments,and the content of Cr,Cd and Pb in grains was the lowest,but the difference was not significant with other spraying selenium treatments.In conclusion,this study suggests that different kinds of selenium fertilizer,spraying time and concentration of selenium fertilizer will have a greater impact on the production of selenium-enriched wheat.Spraying 15 g·ha^-1 standard selenium fertilizer at anthesis was beneficial to increase the physiological activity of wheat after anthesis,and it could not only decrease the content of Cr,Cd and Pb,but also increase the content of se and the proportion of organic se in grains,increasing wheat yield and grain protein content.These conclusions can provide theoretical basis for the production of seleniumenriched wheat in Shanxi Province.