Response Characteristics Of Yield And Quality Of Tibetan Highland Barley To Exogenous Selenium Fertilizer

Selenium is an essential element for humans and animals.Selenium deficiency in human body can cause muscle atrophy,Kashin-Beck disease,Keshan diseases,and other diseases.The prevalence of Kaschin-Beck disease in Tibetan is caused by selenium deficiency.It has a long history of areas,and a serious condition.Dietary of selenium is a simple and safe way for human.Highland barley is very important in the diet structure of Tibetan people.Xigaze is the most important highland barley production area in Tibet.The selenium content of Xigaze highland barley grains can be improved by selenium nutrition enhancement.This is the safest and easiest way to increase the selenium intake of Tibetan people.A total of 83 samples of highland barley（six varieties）and 83 of corresponding cultivated soil samples（corresponding to highland barley grain collection place）were collected from 12 counties of the district of.Xigaze.Clarified the current status of selenium content in Xigaze highland barley and its cultivated soil,and explored the correlation between soil selenium content and highland barley grain selenium.The experiment used Zang Qing 2000 and Ximala 22 as materials.They are the dominant highland barley varieties in Xigaze.This experiment studied the effects of foliar spraying periods,different amounts of selenium fertilizer application,and different different altitudes of highland barley planting areas on selenium content,mineral element content and quality of highland barley grains.The main conclusions obtained from this experiment are as follows:（1）The selenium content range of barley grains in Xigaze is 60.88～186.19μg kg^-1,There is a significant correlation between the total selenium content and available selenium content in soil and the selenium content in grains.The content of absorbable selenium in highland barley was increased,which was beneficial to improve the selenium content of highland barley grains.（2）The yield of Zang Qing 2000 was increased by spraying selenium fertilizer on the leaves at grouting period and full growth period.The yield of Ximara 22 was increased by spraying selenium fertilizer on the leaves at boot stage,grouting period and full growth period.The best period for increasing yield is throughout the entire growth period growth period.The application of 30 g Se/hm²selenium fertilizer significantly increased the yield of highland barley.The yield of highland barley significantly decreases with the elevation of the planting area.（3）After selenium fertilizer treatment,the absorption of Mn and Zn by barley grains is promoted,while the bioavailability of Mg,Fe and Cu is reduced.After spraying selenium fertilizer during the booting,filling,and full growth stages,the polyphenols andβ-glucan content has been increased.After spraying selenium fertilizer throughout the entire growth period,the total flavonoid content in barley grains decreased;Highland barley seed polyphenols andβ-glucan content of glucan showed a trend of first increasing and then decreasing with the increase of spraying amount,while the total flavonoid content of barley seeds showed a continuous downward trend.（4）After spraying selenium fertilizer during the booting,filling,and full growth stages of barley,the selenium content in barley grains was increased.The utilization rate of selenium in barley grains was high during the booting and filling stages,and the selenium content in barley grains increased with the increase of selenium fertilizer dosage.At a fertilization rate of60 g Se/hm²,the selenium content in barley grains exceeded the safety standard,and the selenium content in barley grains decreased with the elevation of the planting site.Considering the changes of yield,mineral element content and nutritional quality content of highland barley under the condition of foliar spraying selenium fertilizer,this experiment recommended that Zangqing 2000 was selected as the production variety of selenium-rich highland barley in Shigatse area.The recommended application amount of sodium selenite was 30 g Se/hm²,and the suitable planting altitude range was below 3900 m.Under this fertilization treatment,the selenium content of highland barley grain could reach 175.51～251.36μg/kg.