Effect Of Different Selenium Contents In The Soil On Yield-Related Traits And Selenium Uptake Of Wheat

Wheat is the third-largest food crop in China and selenium is an essential trace element for human body.Increasing the selenium in wheat grains by applying exogenous selenium can effectively meet the human body’s demand for selenium.In this study,the triticale varieties’Xinong Hei Da Sui’,’Zhou Hei Mai 1’,and the ordinary white wheat variety’Pu Bing 151’were used as experimental materials.Ziyang high selenium ore powder to configure nutrient soil with different selenium content for pot experiment,set S₀（0 added selenium ore powder）,S₁,S₂,S₃ and S₄（selenium content of soil is 4mg/kg,8mg/kg,12mg/kg and 16mg/kg）5 different soil selenium levels,repeated 3times,study the different selenium content in the soil on the yield and yield components of different wheat varieties,chlorophyll content and photosynthetic characteristics of flag leaves,dry matter accumulation and transport,crude protein and other trace element content in grains,and selenium content and transport in various organs in different periods the effect of organic selenium content and selenium utilization rate,the test results showed that:（1）Compared with S₀,the application of high selenium mineral powder in the soil had no significant effect on the tiller number and ear length of wheat,but significantly increased the plant height of’Xinong Hei Da Sui’under the soil selenium content S₂ and S₃（p<0.05）.Increasing soil selenium content can significantly increase the number of spikes per grain and thousand-grain weight of wheat（p<0.05）,and thus increase wheat yield.The maximum yield of the three increased by 23.66%,25.89%and 26.42%compared with S₀,respectively.（2）With the increase of soil selenium content,the chlorophyll content of the flag leaves of the main stems of the three wheat varieties all increased significantly（p<0.05）,showing a trend of first increasing and then decreasing.’Pu Bing 151’reached its maximum value 5days after flowering,’Xinong Hei Da Sui’and’Zhou Hei Mai 1’reached their maximum values at 10 days after anthesis,and the maximum values of the three reached 57.2,60.4,and 64.2,respectively;the net photosynthetic rate of the flag leaves of the three varieties was basically consistent with the chlorophyll content the stomatal conductance and transpiration rate of the main stem flag leaf were not significantly different from those of S₀.The trend of CO₂concentration between the main stem flag leaf cells and the net photosynthetic rate showed the opposite trend.（3）The vegetative organ dry matter allocation of the three wheat varieties under selenium application was:stem+leaf sheath>cob axis+glume>leaf,and the dry matter allocation of vegetative organ in mature stage was:>Stalk+leaf sheath>Cob axis+glume>Leaf.With the increase of soil selenium content,the total dry matter accumulation of the three wheat varieties increased first and then decreased at the flowering and mature stages,and all reached the maximum at the S₂ level.The application of a certain amount of high selenium ore powder in the soil can effectively promote the contribution rate of nutrient dry matter transport before flowering to dry matter accumulation in grains.（4）The application of selenium ore powder in the soil significantly increased the crude protein content of the three wheat varieties（p<0.05）.There was no significant difference between the levels of S₂,S₃,and S₄,but it was significantly higher than the level of S₁（p<0.05）.The largest increases were 3.21%,5.66%and 2.34%.The application of high selenium ore powder in the soil can significantly increase the Fe content in wheat grains（p<0.05）,The maximum values of the three increased by 7.24%,10.78%and 10.04%compared with S₀,respectively;The Zn content of the three wheat varieties was significantly increased in S₃ and S₄（p<0.05）,The maximum value of the three was increased by 2.2%,4.3%and 3.2%compared with S₀;The application of selenium in the soil significantly increased the Mn content of the grains of’Pubing 151’and’Xinong Hei Da Sui’（p<0.05）,the grain Mn content of’Zhou Hei Mai 1’had no significant effect;Under the condition of soil selenium application,the grain Gu content of the three wheat varieties was inhibited.（5）Compared with S₀,the application of high selenium ore powder in the soil can significantly increase the selenium content of wheat organs（p<0.05）,all of which increase with the increase of selenium application amount.The selenium content in the leaves,cobs+glumes and roots of the three wheat varieties decreased from flowering to maturity,the selenium content in the stem increased slightly,and the selenium content in the grain increased significantly（p<0.05）.Compared with S₀,the selenium content and organic selenium content of wheat grains increased significantly after the application of high selenium ore powder in the soil（p<0.05）.The organic selenium content of the three wheat varieties at the S2 level was 0.258,0.288 and 0.273 mg/kg all meet the selenium-enriched wheat standard,and the S2 level is the most suitable soil selenium concentration for selenium-enriched wheat.’Xinong Hei Da Sui’has the best performance among the three varieties,and is suitable as a selenium-rich black wheat variety to be popularized in high-selenium regions such as Shaanxi Ziyang.