Abstract

Aims

Invasive plants may alter soil fungal communities in a way that improves their growth. Nitrogen (N) content of soil affects the symbiosis between plants and arbuscular mycorrhizal fungi (AMF), further determining plant growth. Yet, it is unclear whether altered AMF communities change the dependence of invasive and native species on N-form, and whether N forms alter the invasive plant–AMF interaction (PSI_M).

Methods

Two synthetic plant communities, including four Solidago canadensis individuals and four native plant species, were inoculated with AMF spores from S. canadensis-invaded soils and adjacent non-invaded soils, and were provided with nitrate, ammonia or glutamate. After their growth, the performance of the two plant communities in treatments of AMF origin and N forms, and the pathways of the N forms affecting S. canadensis growth and PSI_M were evaluated.

Important Findings

Solidago canadensis had no obvious N-form dependence in any of the AMF inoculations. Native plant species showed weak N-form dependence, but invasive AMF could remove their N-form dependence. In the absence of N, AMF did not affect growth of S. canadensis and the native plants. In contrast, with N addition, invasive AMF significantly increased belowground and total biomass of the invasive plants but not those of the native plants. Positive PSI_M of S. canadensis was also evidently greater than that of native plant species and was realized through directly or indirectly regulating phenotypic traits including plant height, leaf number and number of rhizomes. Our findings emphasize the importance of plant–AMF interactions and a unique N-acquisition strategy during plant invasions.

中文翻译：

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丛枝菌根真菌对加拿大一枝黄花生长的影响与氮素形态无关

摘要

目的

外来入侵植物可能以改善其生长的方式改变土壤真菌群落。土壤中的氮含量会影响植物与丛枝菌根真菌（AMF）之间的共生关系，从而进一步决定植物的生长。然而，尚不清楚改变的AMF群落是否会改变入侵物种和本地物种对N型的依赖性，以及N形式是否会改变入侵植物与AMF的相互作用（PSI _M）。

方法

向两个合成植物群落（包括四个加拿大一枝黄花个体和四个本地植物物种）接种来自加拿大链霉菌侵染的土壤和邻近的非侵染土壤的AMF孢子，并为其提供硝酸盐，氨水或谷氨酸盐。生长后，评估了两个植物群落在AMF起源和N形态处理中的性能，以及N形态影响加拿大链球菌生长和PSI _M的途径。

重要发现

加拿大一枝黄花在任何AMF接种中均无明显的N型依赖性。本地植物物种显示出弱的N形式依赖性，但侵入性AMF可以消除其N形式依赖性。在没有氮的情况下，AMF不会影响加拿大链球菌和天然植物的生长。相反，添加氮后，入侵AMF显着增加了入侵植物的地下和总生物量，但没有增加天然植物的地下和总生物量。正PSI_中号的加拿大一枝黄花还明显比本地植物物种更大，并且是通过直接或间接调节表型性状（包括植物高度，叶数和根茎数）来实现的。我们的发现强调了植物与AMF相互作用的重要性以及植物入侵期间独特的N捕获策略。