Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (3): 938-951.DOI: 10.1016/j.jia.2024.09.007

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通过优化高密度下玉米的群体光合能力和光氮效率使现代玉米杂交种的产量得到提高

  

  • 收稿日期:2024-04-16 修回日期:2024-09-14 接受日期:2024-07-04 出版日期:2026-03-20 发布日期:2026-02-06

Enhancing yield of modern maize (Zea mays L.) hybrids through optimization of population photosynthetic capacity and light-nitrogen use efficiency under high planting density

Zhenlong Wang1, Pin He2, Xuyao Li1, Tieshan Liu3, Saud Shah4, Hao Ren1, Baizhao Ren1, Peng Liu1, Jiwang Zhang1, Bin Zhao1#   

  1. 1 College of Agronomy, Shandong Agricultural University, Tai’an 271018, China

    2 Seed Station of Tianshui Agriculture and Rural Bureau, Tianshui Agriculture and Rural Bureau, Tianshui 741000, China

    3 Shandong Academy of Agricultural Sciences, Jinan 250100, China

    4 College of Life Science, Linyi University, Linyi 276000, China

  • Received:2024-04-16 Revised:2024-09-14 Accepted:2024-07-04 Online:2026-03-20 Published:2026-02-06
  • About author:Zhenlong Wang, E-mail: 2022110018@sdau.edu.cn; #Correspondence Bin Zhao, E-mail: zhaobin@sdau.edu.cn
  • Supported by:

    The authors are grateful to the reviewers and editors for their constructive review and suggestions for this paper.  This work was supported by the National Natural Science Foundation of China (32071960) and the National Key Research and Development Program of China (2018YFD0300603).

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摘要：

由于玉米生产中耐密、抗倒伏品种的选育，密植已成为玉米高产稳产的有效手段，而优良的杂交种是玉米生产中合理密植的前提。然而，中国不同年代主推的玉米杂交种提高其耐密性的光合作用机理尚不清楚。本研究旨在探究40年来为增强不同密度下的玉米光合性状所做出的育种努力，阐明提高玉米杂交种耐密性的生理生态机制。我们在2019年、2020年和2021年开展了为期3年的研究。我们将1970年到2009年间中国主要推广的8个主要杂交种划分为4个年代，在3个种植密度（45000（D1）、67500（D2）和90000（D3）株·hm-2）下进行了比较。在高密度下，现代杂交种的冠层结构和叶片光合性能与老杂交种相比更为合理，而比叶氮略有下降。在所有处理中，现代杂交种（2000年代）在D3密度下能保持较高的净光合速率和光合氮利用效率（PNUE），因此籽粒产量（GY）最高，与老杂交种（1970年代）相比提高了118.47%。花后叶面积持续时间、叶绿素总含量、光合关键酶活性和PSⅡ光化学最大效率均与GY呈正相关，其中PNUE与GY的相关性更为显著，是玉米杂交种优化的关键指标。基于以上结果，育种工作者应继续在逆境和高密度条件下进行杂交种选育，注重群体结构的优化和光合能力的持续提高，寻找最佳叶片含氮量状态，从而选育出高产、耐密植的杂交种，使玉米GY持续提高。

Abstract:

In maize production, the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields, with superior hybrids serving as a prerequisite for successful high-density cultivation.  However, the photosynthetic mechanisms underlying improved density tolerance in maize hybrids released across different eras in China remain unclear.  This study investigates 40 years of breeding progress toward enhanced photosynthetic traits under varying planting densities and elucidates the physiological and ecological bases of improved density tolerance in maize hybrids.  A three-year field experiment was conducted from 2019 to 2021 to compare eight major Chinese hybrids from four decadal cohorts under three planting densities: 45,000 (D1), 67,500 (D2), and 90,000 (D3) plants ha−1.  At high density (D3), modern hybrids exhibited a more optimal canopy architecture and superior leaf photosynthetic performance compared to older hybrids, despite a slight reduction in specific leaf nitrogen.  Notably, modern hybrids (2000s) were able to maintain higher net photosynthetic rates and photosynthetic nitrogen use efficiency (PNUE) at D3, resulting in the highest grain yield (GY), which was 118.47% greater than that of older hybrids (1970s).  Leaf area duration after anthesis, total chlorophyll content, key photosynthetic enzyme activities, and maximum quantum efficiency of PSII photochemistry were all positively correlated with GY.  Among these, PNUE showed the strongest correlation with grain yield and thus represents a key indicator for optimizing maize hybrids.  Based on these findings, breeders should continue selecting hybrids under high-density and suboptimal conditions, focusing on optimizing population architecture and enhancing photosynthetic capacity while fine-tuning leaf nitrogen status to develop high-yielding, density-tolerant hybrids capable of sustaining long-term increases in maize grain yield.

Key words: maize hybrids , planting density ,  photosynthetic characteristics ,  photosynthetic N use efficiency ,  grain yield