植物生态学报 ›› 2026, Vol. 50 ›› Issue (3): 760-773.DOI: 10.17521/cjpe.2025.0272  cstr: 32100.14.cjpe.2025.0272

• 研究论文 • 上一篇    下一篇

丛枝菌根真菌对豆禾混播植物垂直生态位养分吸收的影响

魏莉1, 王鹏森1, 刘珊1, 樊锐1, 黄楠1, 张建国1, 其美拉姆2, 苟扬1, 刘沫含1, 黄婷1, 周冀琼1,*()()   

  1. 1 四川农业大学草业科技学院, 成都 611130
    2 西藏拉萨市曲水县农业农村和水利局, 拉萨 850600
  • 收稿日期:2025-07-21 接受日期:2026-02-25 出版日期:2026-03-20 发布日期:2026-05-20
  • 通讯作者: *周冀琼(jiqiong_zhou@sicau.edu.cn)
  • 基金资助:
    国家自然科学基金(32271776);四川省自然科学基金(24NSFSC1813);四川省科技教育联合基金(25LHJJ0196);四川省科技教育联合基金(25LHJJ0190)

Arbuscular mycorrhizal fungi influence nutrient uptake along vertical niches in legume-grass mixtures

WEI Li1, WANG Peng-Sen1, LIU Shan1, FAN Rui1, HUANG Nan1, ZHANG Jian-Guo1, Qimeilamu 2, GOU Yang1, LIU Mo-Han1, HUANG Ting1, ZHOU Ji-Qiong1,*()()   

  1. 1 College of Pratacultural Science, Sichuan Agricultural University, Chengdu 611130, China
    2 Qüxü County Bureau of Agriculture, Rural Affairs and Water Resources, Lhasa 850600, China
  • Received:2025-07-21 Accepted:2026-02-25 Online:2026-03-20 Published:2026-05-20
  • Contact: *ZHOU Ji-Qiong(jiqiong_zhou@sicau.edu.cn)
  • Supported by:
    National Natural Science Foundation of China(32271776);Sichuan Provincial Natural Science Foundation(24NSFSC1813);Joint Fund Project of Science and Education in Sichuan Province(25LHJJ0196);Joint Fund Project of Science and Education in Sichuan Province(25LHJJ0190)

摘要:

豆禾混播是修复西南退化草地及提升生产力的重要措施。丛枝菌根真菌(AMF)在其中发挥关键的养分调控作用。但AMF如何调控不同根系深度植物构建的混播群落氮吸收与分配机制仍不明晰。该研究根据植物的固氮特性和根系深度差异, 选取深根型豆科植物苜蓿(Medicago sativa)和浅根型豆科植物白三叶(Trifolium repens), 与两种禾本科植物鸭茅(Dactylis glomerata)和黑麦草(Lolium perenne)单播及混播, 设置不同的AMF接种处理(接种和不接种), 利用15N同位素示踪技术(分别标记3 cm浅层与25 cm深层土壤), 探究AMF对不同根系深度植物氮获取策略及群落功能的影响。结果表明, 混播显著提高了植物群落总生物量, 尤其以“白三叶+鸭茅+黑麦草”混播组合为最佳, 较白三叶或黑麦草单播分别显著增产54.78%和76.58%, 表明浅根型豆科植物与禾本科植物形成了显著的地下生态位互补, 增强了资源利用效率; 相反, 深根型豆科植物苜蓿与禾本科植物因根系空间布局重叠, 种间竞争加强, 混播优势不显著。接种AMF显著促进菌根依赖性较强的白三叶和苜蓿的生物量积累, 削弱了依赖性较弱的禾本科植物鸭茅和黑麦草的竞争优势, 从而提高了豆科植物在群落中的比例; 此外, AMF诱导了植物根系形态的可塑性, 显著增加了白三叶和黑麦草的根系长度。15N示踪结果发现, 两种混播较单播促进了豆科植物的固氮率, 接种AMF进一步强化了这一过程并降低了豆科植物对土壤15N的吸收。同时AMF缩小了禾本科植物在不同土层的15N吸收差异, 促进了其对深层土壤氮的高效利用。AMF通过增强豆科植物固氮效率和促进禾本科植物对深层土壤氮的获取, 实现了群落水平的资源优化配置。该研究验证“浅根型豆科+禾本科”混播并接种AMF是实现地下空间对接与地上高产的最佳策略, 为西南地区人工草地建植提供了理论借鉴。

关键词: 丛枝菌根真菌, 豆禾混播, 深根系, 浅根系, 氮吸收, 生物固氮, 15N示踪

Abstract:

Aims Legume-grass intercropping is an important strategy for restoring degraded grasslands and improving productivity in Southwest China. Arbuscular mycorrhizal fungi (AMF) play a key regulatory role in nutrient uptake within these systems. However, the mechanism by which AMF regulates nitrogen uptake and allocation in intercropping communities composed of plants with varying rooting depths remains unclear.

Methods Based on differences in nitrogen-fixing traits and root depths, this study selected a deep-rooted legume Medicago sativa and a shallow-rooted legume Trifolium repens, intercropped with two grass species, Dactylis glomerata and Lolium perenne. Monocultures and mixtures were established with or without AMF. Using 15N labeling at two soil depths 3 cm shallow and 25 cm deep, we explored the effects of AMF on the nitrogen acquisition strategies and community functions of plants with different root depths.

Important findings Intercropping significantly increased the total community of the plant community. The combination of T. repens + D. glomerata + L. perenne performed best, increasing yield by 54.78% and 76.58% compared to T. repens or L. perenne monocultures, respectively. This highlights a significant belowground niche complementarity between shallow-rooted legumes and grasses, which enhanced resource use efficiency. Conversely, the deep-rooted M. sativa showed spatial root overlap with grasses, intensifying interspecific competition and diminishing in insignificant intercropping advantages. AMF inoculation significantly promoted biomass accumulation in the strongly mycorrhizal-dependent legumes while moderating the competitive dominance of the less-dependent grasses, thereby increasing the legume proportion within the community. Furthermore, AMF induced plasticity in root morphology, significantly increasing the root length of T. repens and L. perenne.15N tracing revealed that intercropping promoted legume nitrogen fixation rates; AMF inoculation further strengthened this process and reduced the uptake of soil 15N by legumes. Meanwhile, AMF narrowed the difference in 15N uptake by grasses across soil layers, promoting more efficient utilization of deep-soil nitrogen. AMF achieved optimal resource allocation at the community level by enhancing legumes nitrogen fixation efficiency and promoting deep soil nitrogen acquisition by grasses. This study verifies that the shallow-rooted legume + grass mixture combined with AMF inoculation is the optimal strategy for achieving belowground spatial partitioning and high aboveground yield, providing a theoretical reference for the establishment of artificial grasslands in Southwest China.

Key words: arbuscular mycorrhizal fungi (AMF), legume-grass mixture, deep root system, shallow root system, nitrogen uptake, biological nitrogen fixation, 15N labeling