Effect of Magnesium Fertilization on Dry Matter Accumulation and Translocation and Grain Filling under Post-Anthesis Heat Stress in Winter Wheat

To explore the mitigation effect of magnesium fertilizer on hight temperature stress of wheat after anthesis,pot experiments were conducted to the effects of magnesium application(0,10 and 20kg·hm-2)on dry matter accumulation and translocation,and the relationships with grain filling under simulated heat stress（Day/Night 32/22 ℃）in artificial climate chamber during grain filling period from 2014 to 2016.Results showed that grain filling rate,grain weight and yield were significant reduced under heat stress.However,magnesium application highly increased grain filling rate and grain yield.Fuether more,heat stress reduced post-anthesis dry matter accumulation,pre-anthesis dry matter translocation,pre-anthesis translocation rate and harvest index,while magnesium application performaned positive effects.Moreover,under heat stress,magnesium application significantly increased plant dry matter accumulation as well as partitioning to grain,which resulted in an enhancement in grain filling rate and grain yield.Magnesium application can alleviate damage of heat stress on post-anthesis plant growth,which will be benefit to grain filling and grain yield formation.