Effects Of Selenium On Cadmium Uptake,Transport And Physiological Characteristics Of Winter Wheat

In recent years,the problem of soil cadmium pollution in China has attracted more and more attention.Based on previous studies,we found that selenium can alleviate Cd poisoning in winter wheat,in this paper,pot experiment and nutrient solution culture experiment were conducted to study the effects of Se application on Cd uptake,migration and distribution in winter wheat.And to explore the feasibility of applying selenium to reduce cadmium in winter wheat and restrict its transport to grain.The main results are as follows:1.Under Cd stress,Se application can increase the yield of winter wheat,which increases from 6.60%to 34.4%.And the Ses(5 mg kg-1)treatment had the largest increase,but the Se10(10 mg·kg-1)treatment or higher will lead a reduce production.2.Under Cd stress,Se application significantly reduced the Cd concentration in the shoots of winter wheat at the seedling stage,jointing stage,filling period and mature period,by 15.0%-81.8%,and the Ses treatment had the largest decrease.In the kernels of mature period,compared with the Se0,the Se10 and Ses treatments decreased the Cd concentration by 47.1%and 70.6%,respectively.The Se5 and Se10 treatments inhibit the transport of Cd to grain and shoot in winter wheat,and the Se5 and Seio treatments also inhibit the Cd uptake by winter wheat from the soil.3.Under the Cd pollution,the Cd mainly existed in the fractions of EXC-Cd and R2O3-Cd at the seedling stage and jointing stage.The Cd mainly existed in the fractions of EXC-Cd,R2O3-Cd and RES-Cd at filling period and mature period.Se application reduced the concentration of EXC-Cd at the seedling stage,jointing stage,filling period and mature period,the Se5 and Seio treatments had the largest decrease;Se application increased the concentration of RES-Cd,the Se5 and Seio treatments had the largest increase.4.Se application reduced the Cd migration rate of root-shoot at the seedling stage and jointing stage.Se application reduced the Cd migration rate of stem-leaf at filling period.Se application reduced the Cd migration rate of glume-grain at mature period.The Se5 treatment had the largest decrease.Se application reduced the Cd distribution ratio of shoots at the seedling stage and jointing stage.Se application reduced the Cd distribution ratio of spike at the filling stage.Se application increased the Cd distribution ratio of roots at all stages.5.Se application significantly increased the root length,root volume,and surface area of winter wheat under Cd stress,Se application reduced the root diameter of winter wheat.The Ses treatment had the largest increase by 119%-402%.6.The Ses treatment significantly reduced the cytoplasmic Cd concentration in the leaves and roots of winter wheat under Cd stress.The Ses treatment significantly reduced the Cd concentration of cell organ in the leaves.The Ses treatment increased the Cd concentration of cell wall in the leaves.The Ses treatment significantly reduced the concentration of FE-Cd and Fw-Cd in leaves under Cd stress,and the Ses treatment reduced the availability of Cd in leaves.