Increasing photosynthetic performance and post-silking N uptake by moderate decreasing leaf source of maize under high planting density  

作　　者：CAO Yu-jun WANG Li-chun GU Wan-rong WANG Yong-jun ZHANG Jun-hua 

机构地区：[1]College of Agriculture,Northeast Agricultural University,Harbin 150030,P.R.China [2]Institute of Agricultural Resources and Environment,Jilin Academy of Agricultural Sciences/State Engineering Laboratory of Maize,National Development and Reform Commission,Changchun 130033,P.R.China

出　　处：《Journal of Integrative Agriculture》2021年第2期494-510,共17页农业科学学报（英文版）

基　　金：the National Key Research and Development Program of China(2016YFD0300103,2017YFD0300603);the Innovation Engineering Plan Project of Jilin Province,China(CXGC2017ZY015)。

摘　　要：To date,little attention has been paid to the effects of leaf source reduction on photosynthetic matter production,root function and post-silking N uptake characteristics at different planting densities.In a 2-year field experiment,Xianyu 335,a widely released hybrid in China,was planted at 60 000 plants ha^(–1 )(conventional planting density,CD) and 90 000 plants ha^(–1) (high planting density,HD),respectively.Until all the filaments protruded from the ear,at which point the plants were subjected to the removal of 1/2 (T1),1/3 (T2) and 1/4 (T3) each leaf length per plant,no leaf removal served as the control(CK).We evaluated the leaf source reduction on canopy photosynthetic matter production and N accumulation of different planting densities.Under CD,decreasing leaf source markedly decreased photosynthetic rate (P_(n)),effective quantum yield of photosystem II (ΦPSII) and the maximal efficiency of photosystem II photochemistry (F_(v)/F_(m)) at grain filling stage,reduced post-silking dry matter accumulation,harvest index (HI),and the yield.Compared with the CK,the 2-year average yields of T1,T2 and T3 treatments decreased by 35.4,23.8 and 8.3%,respectively.Meanwhile,decreasing leaf source reduced the root bleeding sap intensity,the content of soluble sugar in the bleeding sap,post-silking N uptake,and N accumulation in grain.The grain N accumulation in T1,T2 and T3 decreased by 26.7,16.5 and 12.8% compared with CK,respectively.Under HD,compared to other treatments,excising T3 markedly improved the leaf P_(n),ΦPSII and F_(v)/F_(m) at late-grain filling stage,increased the post-silking dry matter accumulation,HI and the grain yield.The yield of T3 was 9.2,35.7 and 20.1% higher than that of CK,T1 and T2 on average,respectively.The T3 treatment also increased the root bleeding sap intensity,the content of soluble sugar in the bleeding sap and post-silking N uptake and N accumulation in grain.Compared with CK,T1 and T2 treatments,the grain N accumulation in T3 increased by 13.1,40.9 and 25.2% on average,respec

关 键 词：different planting densities leaf source reduction canopy photosynthetic matter production post-silking N uptake grain N accumulation 

分 类 号：S513[农业科学—作物学]