Distribution Characteristics Of Selenium In Apocynum Venetum L. ’Songyuan’ And Effects Of Exogenous Selenium Fertilizer On Its Yield And Quality

The forerunner grass seed of saline-alkali land improvement in the west of jilin province—Apocynum venetum L.‘Songyuan’ is a kind of multi-purpose fine plant,which is used for food,medicine,fiber,vegetation restoration and tourism.Scientists found that Apocynum venetum L.‘Songyuan’ has the potential to develop selenium-rich tea.Selenium is one of the essential trace elements in human body.The deficiency of selenium in human body will cause diseases,such as keshan disease and kashin-beck disease.Therefore,in order to study the selenium content and distribution characteristics of Apocynum venetum L.‘Songyuan’ and the effect of exogenous selenium fertilizer on the yield and quality of Apocynum venetum L.‘Songyuan’,theoretical basis was provided for the development and utilization of selenium-enriched Apocynum venetum L.‘Songyuan’ tea.This experiment was carried out in the western part of jilin province,and treated with different selenium fertilizer concentrations.Samples were taken in the early flowering,peak flowering and late flowering.The main conclusions are as follows:(1).Apocynum venetum L.‘Songyuan’ is selenium-rich plants.The selenium-selenium content of Apocynum venetum L.‘Songyuan’ and its associated plants was analyzed in typical meadow steppe of western jilin province.Experiments show that,The soil growing in Apocynum venetum L.‘Songyuan’ belongs to selenium-deficient area,and its total selenium content is less than 0.125 mg/kg.The selenium content in Apocynum venetum L.‘Songyuan’ was 148% of the selenium content in soil,and the selenium content in different associated plants growing on the same plot in the same year was significantly lower than that in Apocynum venetum L.‘Songyuan’.Therefore,Apocynum venetum L.‘Songyuan’ is selenium-rich plants.(2).The change of selenium content in different organs of Apocynum venetum L.‘Songyuan’ was consistent with the growth period.In different growth period,samples were taken from different organs of Apocynum venetum L.‘Songyuan’ to analyze the change of selenium content in various organs of Apocynum venetum L.‘Songyuan’.Experiments show that,With the growth period,the selenium content in each organ first increased and then decreased,and reached the maximum value in different periods.The selenium content in the leaves reached the maximum value of 1.59mg/kg at the peak of flowering,which was in line with the national standard for selenium-rich tea.The selenium content in stem reached the maximum value of 0.96 mg/kg in bud stage.The selenium content in flowers reached a maximum value of 0.94 mg/kg at the pod bearing stage.The selenium content in seeds reached the maximum value of 0.30 mg/kg in fruit.The selenium content in the whole plant reached the maximum value of 1.16mg/kg in the bud stage.(3).Selenium fertilizer significantly increased the contents of selenium in different organs and biomass of Apocynum venetum L.‘Songyuan’(P<0.05).Set different selenium concentration treatments,sample the Apocynum venetum L.‘Songyuan’,and the effects of different selenium concentrations on the selenium content and biomass of various organs of Apocynum venetum L.‘Songyuan’ were analyzed.Experiments show that,With the increase of selenium application concentration,the selenium content in the organs of Apocynum venetum L.‘Songyuan’ increased slowly at first and then rapidly,but there was no inhibition.The allocators of different organs showed from high to low: root > leaf > stem > flower.From the perspective of biomass correlation,selenium content is significantly correlated with the selenium content of all organs of Apocynum venetum L.‘Songyuan’,while the selenium content of all organs of Apocynum venetum L.‘Songyuan’ is significantly correlated with the selenium application.Therefore,selenium application can significantly increase the biomass of p.chinensis.(4).Selenium application can significantly improve the yield,agronomic characters and quality of Apocynum venetum L.‘Songyuan’(P<0.05).Different concentrations of selenium were used to sample Apocynum venetum L.‘Songyuan’ at different harvest periods.Experiments show that,with the increase of selenium concentration,the selenium content in Apocynum venetum L.‘Songyuan’ tea will also increase,and there are significant differences between the treatments.After 30 days of selenium application,namely the flowering period,the plant height,yield and selenium content of Apocynum venetum L.‘Songyuan’ tea increased the most,reaching 5.8%,21.3% and 567% respectively.The ratio of stem to leaf decreased by 6.7%.The most influential quality indicators.Therefore,if high yield and good quality selenium-rich Apocynum venetum L.‘Songyuan’ tea is to be obtained,it should be treated with selenium at a concentration of 2mg/kg and sampled at the peak flowering period of after selenium application.