高密度条件下株型改良对春玉米根-冠特征及籽粒产量的影响  

Effects of Plant Type Improvement on Root-Canopy Characteristics and Grain Yield of Spring Maize Under High Density Condition

作　　者：赵耀 程前 徐田军[3] 刘正 王荣焕[3] 赵久然[3] 陆大雷[2] 李从锋[1] ZHAO Yao;CHENG Qian;XU TianJun;LIU Zheng;WANG RongHuan;ZHAO JiuRan;LU DaLei;LI CongFeng(Institute of Crop Science,Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology and Ecology,Ministry of Agriculture and Rural Affairs,Beijing 100081;Agricultural College of Yangzhou University/Jiangsu Key Laboratory of Crop Genetics and Physiology,Yangzhou 225009,Jiangsu;Maize Research Center,Beijing Academy of Agriculture&Forestry Sciences/Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding,Beijing 100097)

机构地区：[1]中国农业科学院作物科学研究所/农业农村部作物生理生态重点实验室,北京100081 [2]扬州大学农学院/江苏省作物遗传生理国家重点实验室培育点,江苏扬州225009 [3]北京市农林科学院玉米研究中心/玉米DNA指纹及分子育种北京市重点实验室,北京100097

出　　处：《中国农业科学》2025年第7期1296-1310,共15页Scientia Agricultura Sinica

基　　金：国家玉米产业技术体系专项(CARS-02-14);国家重点研发计划(2023YFD2301702);内蒙古自治区科技计划(2022YFD0041)。

摘　　要：【目的】增加种植密度是目前生产上提升玉米产量的主要农艺措施之一,但增密会导致群体结构不合理进而降低光照等有限资源利用效率,限制玉米产量潜力释放。基因编辑可以通过改良玉米株型来优化冠层结构使其适应密植进而增加产量,探明株型改良对春玉米根冠特性、籽粒产量及密度响应的影响及机制,可为春玉米的株型改良和密植高产提供理论与技术支撑。【方法】于2019和2020年在吉林省公主岭试验站进行为期2年的田间试验,以京科968和该品种的株型改良型品种京科Y968为试验材料,设置3个种植密度分别为6.0万株/hm^(2)(D1)、7.5万株/hm^(2)(D2)、9.0万株/hm^(2)(D3)。研究相同遗传背景下株型对春玉米根-冠特征和产量的影响。【结果】在D1条件下,2种不同株型的春玉米品种间叶面积指数(LAI)、净光合速率(Pn)、光能利用效率(PUE)、干物质积累量及籽粒产量均无显著差异。但与京科968相比,京科Y968在D3条件下具有相对较高的主根条数(7.2%)和较大的根系干物质重量(6.0%),促进了营养物质的吸收;同时,在D2和D3条件下,京科Y968植株上部、中部和下部均具有相对较低的茎叶夹角和较高叶向值、叶面积指数。因此,D2和D3条件下灌浆中后期京科Y968穗位叶的Pn分别提高了7.5%和7.7%,PUE提高了4.3%和10.8%。结构方程模型分析表明,较高的叶向值和叶面积指数可正向直接地提升地上部干物质积累量,进而增加籽粒产量8.7%(D2)和11.2%(D3)。【结论】株型的改良使京科Y968在高密度条件下具有更高的主根条数和更大的根系干物质重,有利于地下部营养吸收,同时其叶片更为紧凑,光合速率显著提高,冠层光能利用率得到有效提升,根-冠结构更为合理,促进了地上部干物质积累,进而可以获得相对较高的籽粒产量。【Objective】Increasing planting density is a key agronomic strategy to enhance maize yield;however,excessive density may result in an imbalanced population structure,reduced utilization efficiency of limited resources(e.g.,light),and suppressed yield potential.Gene editing can optimize canopy architecture through targeted improvement of maize plant type,thereby enhancing adaptability to high-density planting and boosting yield.Elucidating the effects of plant type improvement on root-shoot characteristics,grain yield,and density response in spring maize,as well as the underlying mechanisms,will provide theoretical and technical foundations for optimizing plant type and achieving high-yield dense planting in spring maize.【Method】The field experiment was conducted at Gongzhuling farm in Jilin,China.In this study,two maize hybrids,includding Jingke 968 and the improved plant types Jingke Y968,were grown with 60000 plants/hm^(2)(D1),75000 plants/hm^(2)(D2)and 90000 plants/hm^(2)(D3)in 2019 and 2020,respectively.The effects of two plant types of spring maize of the same genetic background on the root-canopy characteristics and yield of spring maize were studied.【Result】Under normal density conditions(D1),there were no significant differences in leaf area index(LAI),net photosynthetic rate(Pn),PAR utilization(PUE),dry matter accumulation and grain yield between the two different plant types spring maize cultivars.However,compared with Jingke 968,under D3 conditions,the improved plant type Jingke Y968 had a relatively high number of main roots(7.2%)and a relatively large weight of root dry matter(6.0%),which promoted the absorption of nutrients;furthermore,under D2 and D3 conditions,Jingke Y968 significantly improved the canopy structure of maize,so that the upper,middle and lower parts had relatively low leaf angles,higher leaf orientation and LAI,and the excellent canopy structure increased the Pn of mid-to-late ear leaves of(7.5%(D2)and 7.7%(D3))and PUE(4.3%(D2)and 10.8%(D3)).The structural equation result

关 键 词：春玉米 种植密度 株型改良 根系特性 冠层结构 

分 类 号：S513[农业科学—作物学]