施镁对花后高温胁迫下小麦干物质积累转运和籽粒灌浆的影响

为明确镁对小麦花后高温胁迫的缓解效应,采用人工气候室模拟增温的方法,研究了灌浆期高温胁迫(昼/夜32/22℃)下施镁(0、10和20kg·hm~(-2))对小麦花后干物质积累转运的影响及其与籽粒灌浆的关系。结果表明,灌浆期高温胁迫显著降低了小麦籽粒的灌浆速率、粒重和产量,施用镁肥提高了小麦籽粒灌浆速率和产量。高温胁迫降低了小麦花后干物质积累量、花前干物质转运量、转运率和收获指数,施镁对花后干物质积累和转运量及收获指数有显著正效应。高温胁迫下施镁提高了植株干物质积累量及在籽粒中的分配比例,从而提高了灌浆速率和粒重。孕穗期施镁能有效缓解花后高温胁迫对小麦植株的伤害,有助于籽粒灌浆和产量的形成。

Effect of Magnesium Fertilization on Dry Matter Accumulation and Translocation and GrainFilling 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 20 kg·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.