Yang Xionggui, Shen Kaiping, Xia Tingting, He Yuejun, Guo Yun, Wu Bangli, Han Xu, Yan Jiawei, Jiao Min
Forestry College, Research Center of Forest Ecology, Guizhou University, Guiyang 550025, China.
College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, China.
Plants (Basel). 2023 Jun 1;12(11):2195. doi: 10.3390/plants12112195.
Plant invasion has severely damaged ecosystem stability and species diversity worldwide. The cooperation between arbuscular mycorrhizal fungi (AMF) and plant roots is often affected by changes in the external environment. Exogenous phosphorus (P) addition can alter the root absorption of soil resources, thus regulating the root growth and development of exotic and native plants. However, it remains unclear how exogenous P addition regulates the root growth and development of exotic and native plants mediated by AMF, affecting the exotic plant invasion. In this experiment, the invasive plant and native plant were selected and cultured under intraspecific (Intra-) competition and interspecific (Inter-) competition conditions, involving inoculation with (M) and without AMF (M) and three different levels of P addition including no addition (P), addition with 15 mg P kg soil (P), and addition with 25 mg P kg soil (P) for the two species. Root traits of the two species were analyzed to study the response of the two species' roots to AMF inoculation and P addition. The results showed that AMF significantly promoted the root biomass, length, surface area, volume, tips, branching points, and carbon (C), nitrogen (N), and P accumulation of the two species. Under M treatment, the Inter- competition decreased the root growth and nutrient accumulation of invasive but increased the root growth and nutrient accumulation of native relative to the Intra- competition. Meanwhile, the exotic and native plants responded differently to P addition, exhibiting root growth and nutrient accumulation of invasive increased with P addition, whereas native reduced with P addition. Further, the root growth and nutrition accumulation of native were higher than invasive under Inter- competition. In conclusion, exogenous P addition promoted the invasive plant but reduced the native plant in root growth and nutrient accumulation regulated by AMF, although the native plant outcompeted the invasive plant when the two species competed. The findings provide a critical perspective that the anthropogenic P fertilizer addition might potentially contribute to the successful invasion of exotic plants.
植物入侵已严重破坏了全球生态系统的稳定性和物种多样性。丛枝菌根真菌（AMF）与植物根系之间的合作常常受到外部环境变化的影响。外源添加磷（P）会改变植物根系对土壤资源的吸收，从而调节外来植物和本地植物的根系生长发育。然而，外源添加P如何通过AMF介导调节外来植物和本地植物的根系生长发育，进而影响外来植物入侵，目前尚不清楚。在本实验中，选择入侵植物和本地植物，在种内（Intra-）竞争和种间（Inter-）竞争条件下进行培养，涉及接种AMF（M）和不接种AMF（M），并对两个物种设置三种不同水平的P添加，包括不添加（P）、添加15 mg P kg土壤（P）和添加25 mg P kg土壤（P）。分析了两个物种的根系性状，以研究两个物种根系对AMF接种和P添加的响应。结果表明，AMF显著促进了两个物种的根生物量、长度、表面积、体积、根尖数、分支点以及碳（C）、氮（N）和P的积累。在M处理下，与种内竞争相比，种间竞争降低了入侵植物的根系生长和养分积累，但增加了本地植物的根系生长和养分积累。同时，外来植物和本地植物对P添加的反应不同，入侵植物的根系生长和养分积累随P添加而增加，而本地植物则随P添加而减少。此外，在种间竞争下，本地植物的根系生长和养分积累高于入侵植物。总之，外源添加P在AMF介导的根系生长和养分积累方面促进了入侵植物，但降低了本地植物，尽管在两个物种竞争时本地植物胜过入侵植物。这些发现提供了一个关键视角，即人为添加磷肥可能潜在地促进外来植物的成功入侵。
