不同夜间温度条件下外源水杨酸对大豆产量的调控作用OA北大核心CSTPCD

In the context of global climate warming,high night temperatures have emerged as a detrimental factor impacting soybean yield.Therefore,it is crucial to explore effective strategies to mitigate the negative effects caused by elevated night temperatures.Salicylic Acid(SA),an essential plant hormone,has been proven to enhance plants′ resilience against stressors like high temperature and drought when externally applied.In this study,two soybean varieties at similar growth stages,namely Zhonghuang 39 and Zhonghuang 76,were selected for experimentation.The experiment involved setting three different night temperatures(T1:18℃,T2:23℃,T3:28℃)and applying three concentrations of SA(SA0:CK,SA1:0.1 mmol·L-1 SA,SA2:0.5 mmol·L-1 SA)under each respective temperature condition in order to investigate the regulatory effect of exogenous SA on soybean yield during the seed filling stage under elevated night temperatures.The research findings demonstrate that an increase in night temperature results in a reduction in the number of soybean pods per plant,seeds per plant,above ground biomass,yield,and harvest index when compared to the T1+CK treatment.With elevated night temperatures,the yield of Zhonghuang39 and Zhonghuang76 decreased by6.34%-27.13%and14.99%-45.66%,respectively.With the temperature increased at night,application of SA can significantly enhance soybean net photosynthetic rate,above ground biomass,pods number per plant and seeds yield while reducing respiration intensity,thereby substantially improving yield and harvest index.The performance consistency is observed across both varieties.Among them,when exposed to temperature of 28℃at night,the application of SA through spraying can result in an increase in soybean yield ranging from 45.69%to 48.55%.The research findings suggest that external administration of SA can partially mitigate the yield loss caused by high night temperatures and enhance the harvest index.