Effect Of Foliar Application Of Selenium Fertilizer On Physiological Property,yield Formation And Element Absorption In Foxtail Millet

In recent years,the people pay more and more attention to the structure of food nutrition.And the functional agriculture has become an important part of modernized agriculture.In this paper,the influence of foliar application of selenium fertilizer on uptake,partitioning and accumulation were researched in foxtail millet.And it provide a theoretical basis for improving the nutrition of the grain and the rational application of selenium fertilizer,and making a certain contribution to meet the needs of people’s selenium dietary supplement.This experiment studied from following aspects to screen out the appropriate selenium application concentration and selenium application period: yields affected by selenium,the physiological function of selenium,the distribution and accumulation of millet by selenium,and the effect of selenium on the absorption and accumulation of grain mineral elements and heavy metals.The results showed that both yields and selenium content can be increased by foliar spraying 30g/hm2 of selenium fertilizer in growing stage.The results of the study are as follows:(1)The application of suitable concentration of foliar selenium fertilizer during different growth periods can improve the physiological activity of millet and inhibited at the high concentration.Leaf antioxidant ability was raised by spraying selenium fertilizer with 30g/hm2.The performance is chlorophyll content was increased,SOD,PODand CAT activity increased,and MDA content decreased.Leaf aging was delayed by spraying selenium fertilizer with 15g/hm2 and 30g/hm2.It is expressed in free proline content reduced.But free proline content increased when spray selenium fertilizer with 45g/hm2,because alleviate the high selenium level caused by selenium stress.When spray selenium fertilizer with 45g/hm2,SOD,POD and CAT activity are reduced,MDA content increased.(2)It was found that the content of free proline decreased,SOD,POD,CAT activity increased significantly,MDA content decreased while 3-5 days after spraying selenium fertilizer with suitable concentration.After 5 days,free proline content rised to the original level or higher than the control,and SOD,POD,CAT activity decreased,MDA content increased.(3)Efficiency of light energy utilization of millet leaves was improved,heat dissipation reduced,thus photosynthesis promoted when spraying suitable concentration of foliar selenium fertilizer.With 30g/hm2 selenium fertilizer,the Fv/Fm,Y(II),ETR and q P improved effectively,and the q N reduced.But it was exhibiting inhibition with 45g/hm2 selenium.Spraying different concentration of foliar selenium fertilizer,the grain leaf net photosynthesis rate(Pn),the transpiration rate(Tr)and the pore conductivity(Gs)were increased with the increase of the selenium concentration,and the concentration of carbon dioxide(Ci)increased but higher than the control.So,the millet photosynthesis improved effectively with 30g/hm2 selenium fertilizer.(4)The yield and its composition factors of millet were improved when applied suitable concentration of foliar selenium fertilizer.The dry weight of each part,single spike grain weight,spike thickness,thousand grain weight and yield were improved significantly by 30g/hm2 selenium fertilizer.The results show that the effect of yield with foliar selenium fertilizer was achieved by improving the quality and size of grain.And the yield improved by an average of 21.23%.In addition,yield reduced with 45g/hm2.(5)The grain selenium content was linearly related to selenium concentration,while the content of grain zinc and iron have no linear relationship with grain selenium content.With the increase of selenium concentration,the selenium content of each part of the grain was positive correlation,and the distribution ratio was leaf>grain>stem>root.The zinc and iron content was increased significantly in 15g/hm2 and30g/hm2 selenium concentration.And the distribution ratio of zinc content was leaf>stem>grain>root,the distribution ratio of iron content was root>leaf>stem>grain.The content of grain heavy metals(Hg,Cd,As)decreased firstly and then rised with the increase of selenium concentration,and the heavy metals content reached the lowest with 30g/hm2.(6)The effect of foliar selenium fertilizer in different concentration was different.When spraying foliar selenium fertilizer in booting stage,yield and physiological activity improved more than filling stage.While spraying foliar selenium fertilizer in filling stage,it’s more beneficial to the absorption and accumulation of zinc and iron,and the grain heavy metal(Hg,Cd,As)content reduced.