Plant Diversity ›› 2024, Vol. 46 ›› Issue (04): 510-518.DOI: 10.1016/j.pld.2024.04.003

• Articles • Previous Articles    

Increased dependence on nitrogen-fixation of a native legume in competition with an invasive plant

Meixu Hana, Haiyang Zhangb, Mingchao Liuc, Jinqi Tangd, Xiaocheng Guoc, Weizheng Rena, Yong Zhaoa, Qingpei Yanga, Binglin Guoa, Qinwen Hana, Yulong Fengc, Zhipei Fenga, Honghui Wue,f, Xitian Yanga, Deliang Konga   

  1. a. College of Forestry, Henan Agricultural University, Zhengzhou 450002, China;
    b. College of Life Science, Hebei University, Baoding 071002, China;
    c. Liaoning Key Laboratory for Biological Invasions and Global Changes, College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, Liaoning 110866, China;
    d. College of Horticulture, China Agricultural University, Beijing 100193, China;
    e. State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
    f. Key Laboratory of Arable Land Quality Monitoring and Evaluation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
  • Received:2023-12-11 Revised:2024-04-03 Published:2024-07-29
  • Contact: Deliang Kong,E-mail:deliangkong@henau.edu.cn,deliangkong1999@126.com
  • Supported by:
    This study was funded by the National Natural Science Foundation of China (32171746, 31870522, 42077450, 32371786), the leading talents of basic research in Henan Province, Funding for Characteristic and Backbone Forestry Discipline Group of Henan Province, the Scientific Research Foundation of Henan Agricultural University (30500854), and Research Funds for overseas returnee in Henan Province, China. This work also was supported by National Key Research and Development Program of China (2019YFE0117000).

Abstract: Suppression of roots and/or their symbiotic microorganisms, such as mycorrhizal fungi and rhizobia, is an effective way for alien plants to outcompete native plants. However, little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents. Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant, Xanthium strumarium, and a common native legume, Glycine max. We measured traits related to root and nodule quantity and activity and mycorrhizal colonization. Compared to the monoculture, fine root quantity (biomass, surface area) and activity (root nitrogen (N) concentration, acid phosphatase activity) of G. max decreased in mixed plantings; nodule quantity (biomass) decreased by 45%, while nodule activity in N-fixing via rhizobium increased by 106%; mycorrhizal colonization was unaffected. Contribution of N fixation to leaf N content in G. max increased in the mixed plantings, and this increase was attributed to a decrease in the rhizosphere soil N of G. max in the mixed plantings. Increased root quantity and activity, along with a higher mycorrhizal association was observed in X. strumarium in the mixed compared to monoculture. Together, the invasive plant did not directly scavenge N from nodule-fixed N, but rather depleted the rhizosphere soil N of the legume, thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source. The quantityactivity framework holds promise for future studies on how native legumes respond to alien plant invasions.

Key words: Mycorrhizal strategy, Nitrogen depletion, Plant invasion, Root nutrient acquisition strategy, Symbiotic nitrogen fixation