Irrigation mitigates the heat impacts on photosynthesis during grain filling in maize

作     者：WANG Xing-long ZHU Yu-peng YAN Ye HOU Jia-min WANG Hai-jiang LUO Ning WEI Dan MENG Qing-feng WANG Pu WANG Xing-long;ZHU Yu-peng;YAN Ye;HOU Jia-min;WANG Hai-jiang;LUO Ning;WEI Dan;MENG Qing-feng;WANG Pu

作者机构：College of Agronomy and BiotechnologyChina Agricultural UniversityBeijing 100093P.R.China 

出 版 物：《Journal of Integrative Agriculture》 (农业科学学报（英文版）)

年 卷 期：2023年第22卷第8期

页      面：2370-2383页

核心收录：

学科分类：09[农学] 0901[农学-作物学] 

基　　金：supported by the Key R&D Program Project in Hebei Province,China(22326408D) the 2115 Talent Development Program of China Agricultural University 

主　　题：high temperature soil water content photosynthesis chlorophyll fluorescence maize 

摘      要：Elevating soil water content(SWC)through irrigation was one of the simple mitigation measures to improve crop resilience to heat *** response of leaf function,such as photosynthetic capacity based on chlorophyll fluorescence during the mitigation,has received limited attention,especially in field conditions.A two-year field experiment with three treatments(control treatment(CK),high-temperature treatment(H),and high-temperature together with elevating SWC treatment(HW))was carried out during grain filling with two maize hybrids at a typical station in North China ***,the net photosynthetic rate(Pn)was improved by 20%,and the canopy temperature decreased by 1–3℃ in HW compared with in H in both ***,the higher SWC in HW significantly improved the actual photosynthetic rate(Phi2),linear electron flow(LEF),variable fluorescence(F_(v)),and the maximal potential quantum efficiency(F_(v)/F_(m))for both ***,different responses in chlorophyll fluorescence between hybrids were also *** higher SWC in HW significantly improved thylakoid proton conductivity(g H^(+))and the maximal fluorescence(F_(m))for the hybrid *** the hybrid XY335,the proton conductivity of chloroplast ATP synthase(v H^(+))and the minimal fluorescence(Fo)was increased by the *** structural equation model(SEM)further showed that SWC had significantly positive relationships with Pn,LEF,and F_(v)/F_(m).The elevating SWC alleviated heat stress with the delayed leaf senescence to prolong the effective period of photosynthesis and enhanced leaf photosynthetic capacity by improving Phi2,LEF,Fv,and F_(v)/F_(m).This research demonstrates that elevating SWC through enhancing leaf photosynthesis during grain filling would be an important mitigation strategy for adapting to the warming climate in maize production.