The Response Of Different Waxy Corn Varieties To Selenium Fertilizer Treatments

Selenium is one of the 14 trace elements necessary for the human body,and there is a certain correlation between selenium and heavy metals such as cadmium,chromium,arsenic,and nickel.Waxy corn is a popular fresh food crop,in which sweetness is one of the most important qualities that affect the taste of waxy corn,and the sugar content in the grain can directly reflect the sweetness of waxy corn.In order to explore the physiological mechanism of the effects of different selenium fertilizer treatments on waxy corn,increase the yield of waxy corn,improve the sugar content in grains,and clarify the optimal amount of selenium fertilizer for the safe production of selenium-enriched corn,this study adopted a 2-factor split zone design method.The agronomic traits and yields,different physiological indexes,sugar and selenium content in grains and 4 toxic heavy metal elements of two glutinous corn varieties currently promoted under different selenium fertilizer treatments in Shanxi were compared and studied.The main findings are as follows:（1）Spraying pure selenium on leaves with an amount of 45 g·hm^-2 has a certain promotion effect on the population leaf area,seed emergence rate,fresh ear and fresh biological yield of the two waxy corn varieties,and the two varieties CTN1965 and JN20 The comprehensive values of membership functions are 0.356 and 1,respectively.When the pure selenium dosage of basal selenium-enriched organic fertilizer was 1.25 mg·kg^-1,the population leaf area,seed yield,and fresh ear yield of the two waxy corn varieties were the highest,and their membership functions were 0.725 and 0.998,respectively.（2）The pure selenium treatment with a foliar spraying rate of 45 g·hm^-2 and a base application rate of 1.25 mg·kg^-1 can increase the POD activity,GSH content and soluble protein content in waxy corn leaves,while also reducing MDA It also promotes the increase of chlorophyll content in waxy corn leaves.And under this spray rate and base rate,the physiological characteristics are optimal.（3）When selenium was sprayed on the leaves,the soluble sugars in the grains of the two waxy corn varieties increased by 30.810% and 28.085% respectively compared with the control;when selenium fertilizer was applied as the base fertilizer,the soluble sugar content increased by48.122% and 43.299%;when selenium was sprayed on the leaves,the sucrose content was increased by 48.122% and 43.299%.Compared with the control group,the content increased by29.327% and 21.570% respectively;when basal selenium fertilizer was applied,the sucrose content increased by 44.099% and 43.850%,and the amount of selenium sprayed on the foliar surface was 45 g·hm^-2,and the amount of selenium fertilizer applied was The best performance was under the treatment of 1.25 mg·kg^-1.（4）The safety thresholds of selenium content in the kernels of two waxy corn varieties under foliar spray and basal application were 63.968 g·hm^-2,89.532 g·hm^-2 and 1.502 mg·kg^-1,1.938mg·kg^-1,respectively.Under this selenium spray rate and base application rate,the average selenium content of the two waxy corn varieties can reach the upper safe limit of 300 μg·kg^-1.（5）The selenium content in the organs of the two waxy corn varieties increased significantly under basal selenium fertilizer,and the selenium content distribution was as follows:root>leaf>stalk>husk leaves.The highest selenium content in roots reached 114.472 mg·kg^-1,which was an increase of 90.945% compared to the control.Through comprehensive analysis,the effect of increasing the selenium content in each organ of the two waxy corn varieties was the best under the highest selenium application rate of 5 mg·kg^-1.（6）Foliar selenium spraying and basal selenium fertilizer application can effectively reduce the content of 4 toxic heavy metal elements in waxy corn kernels.The comprehensive membership function value of the selenium spraying rate is 45 g·hm^-2.Ni has a significant antagonistic effect;basal selenium fertilizer has the best comprehensive inhibitory effect on the content of Cd,Cr,As and Ni under the condition of 1.25 mg·kg^-1.In summary,under the experimental conditions,the average membership function of the indicators of the two waxy corn varieties under different selenium application methods and different selenium application rates was obtained: the foliar selenium spray amount was 45 g·hm^-2Pure selenium,the basal selenium fertilizer amount should be 1.25 mg pure selenium per 1 kg of soil.The amount of basal selenium-enriched fertilizer in the field soil needs to be further studied and determined.