中国农业科学2025，Vol.58Issue(7)：1296-1310,15.DOI:10.3864/j.issn.0578-1752.2025.07.004
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
摘要
Abstract
[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 60 000 plants/hm2(D1),75 000 plants/hm2(D2)and 90 000 plants/hm2(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 results showed that higher leaf direction values and LAI could positively and directly increase the accumulation of dry matter in the aboveground,thereby increasing grain yield(8.7％(D2)and 11.2％(D3)).[Conclusion]In summary,the improvement of plant type enabled Jingke Y968 to have higher main root number and larger root dry matter weight under high-density conditions,which was conducive to nutrient absorption in the underground part.Meanwhile,its leaves were more compact,Pn was significantly increased,PUE was effectively improved,and root-canopy characteristics were more reasonable,which promoted dry matter accumulation in the above-ground part.Thus,the relatively high grain yield could be obtained.关键词
春玉米/种植密度/株型改良/根系特性/冠层结构Key words
spring maize/planting density/plant type improvement/root characteristics/canopy structure引用本文复制引用
赵耀,程前,徐田军,刘正,王荣焕,赵久然,陆大雷,李从锋..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[J].中国农业科学,2025,58(7):1296-1310,15.基金项目
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) （CARS-02-14）
