减源对密植夏玉米光合性能及根系特性调控效应研究  

Regulation effects of leaf source reduction on the photosynthetic performance and root characteristics of densely planted summer maize

作　　者：杨胜飞 肖金宝 王佩 白延倩[1,2] 杨任涛 刘铁宁 韩清芳[1,2] 贾志宽 Yang Shengfei;Xiao Jinbao;Wang Pei;Bai Yanqian;Yang Rentao;Liu Tiening;Han Qingfang;Jia Zhikuan(College of Agronomy,Northwest A&F University,Institute of Water-saving Agriculture in Arid Areas,of China,Yangling 712100,China;Key Laboratory of Crop Physi-ecology and Tillage Science in Northwest Loess Plateau,Ministry of Agriculture,Yangling 712100,China)

机构地区：[1]西北农林科技大学农学院中国旱区节水农业研究院,陕西杨凌712100 [2]农业部西北黄土高原作物生理生态与耕作重点实验室,陕西杨凌712100

出　　处：《山西农业大学学报（自然科学版）》2023年第6期62-79,共18页Journal of Shanxi Agricultural University(Natural Science Edition)

基　　金：国家自然科学基金(K3050216083)。

摘　　要：[目的]玉米密植条件下存在叶片冗余,适度去叶有利于玉米光热资源再分配,提高玉米产量。[方法]本试验于2021年和2022年进行,选用紧凑型玉米品种郑单958,采用二因素裂区试验设计,主区为种植密度:常规密度(67500株·hm-2)和高密度(97500株·hm-2);副区为减源强度:于吐丝后7 d分别移除植株顶部2片叶、4片叶和6片叶,以不减叶处理为对照。对开花期、灌浆期、乳熟期和蜡熟期的玉米植株形态、光合性能、根系特性和产量构成因素等指标进行分析,探究玉米光合性能和根系特性对叶源减少的响应。[结果]常规密度下去叶不利于玉米叶源光合性能的改善,而高密度种植条件下去除植株顶部2片叶能够延缓剩余叶源的衰老,叶面积指数衰减程度减缓,其群体光合速率(CAP)在灌浆期仍较对照高出24.5%。常规密度种植条件下,去叶不利于深层根系生长,降低根系活性。而高密度种植条件下去2叶能够促进40~100 cm土层根系生长,蜡熟期根系干重较对照增加53.7%,根系活性增强7.0%。常规密度下去2叶、去4叶和去6叶会导致玉米产量分别下降7.5%,21.7%和26.5%,而高密度种植条件下去2叶籽粒产量较对照提高7.8%,而过度减源处理(去4叶和去6叶)产量降低幅度分别为14.5%和22.7%。[结论]由此可见,常规密度下减少叶源不利于玉米生长,而高密度种植条件下适度减少叶源能显著改善玉米光合性能,增强根系特性,最终实现玉米产量提升。[Objective]Under high-density planting conditions for maize,leaf redundancy exists.Moderate defoliation can aid in redistributing internal resources and improve maize yield.[Methods]This study,conducted in 2021 and 2022,utilized the compact maize variety Zhengdan958.A two-factor split-zone experimental design was used,with the primary factor focusing on planting density:conventional density(67500 plants·hm-2)and high-density(97500 plants·hm-2).The secondary factor involved source reduction intensity:removing the top 2,4,and 6 leaves of the plant 7 days after silking,with the treatment of no leaf reduction served as the control.Analysis of maize plant morphology,photosynthetic performance,root characteristics,and yield components was carried out at the stages of anthesis,grain filling,milky,and waxing stages to investigate the response of maize photosynthetic performance and root characteristics to reduced leaf source.[Results]The results of the study demonstrated that leaf removal at conventional density did not enhance maize's photosynthetic performance,while removing the top two leaves under high-density planting conditions delayed the senescence of the remaining leaves,slowed the decline of the leaf area index,and increased the population photosynthetic rate(CAP)by 24.5%during the filling period compared to the control.Under conventional density planting conditions,defoliation was detrimental to deep root growth and reduced root activity.However,under high-density planting,defoliation encouraged root growth in the 40~100 cm soil layer,resulting in a 53.7%increase in root dry wright at the wax maturity stage compared to the control,with root activity increasing by 7.0%.Removing 2,4,or 6 leaves under conventional density resulted in yield reduction of 7.5%,21.7%,and 26.5%,respectively.In contrast under high-density planting conditions,removing 2 leaves increased kernel yield by 7.8%compared to the control,while excessive source reduction treatments(removing 4 or 6 leaves)reduced maize yield by 14.5%and 22.7%,r

关 键 词：夏玉米 光合性能 根系特性 减少叶源 产量 

分 类 号：S515[农业科学—作物学] S35