Arbuscular mycorrhizal fungi (AMF) play a central role in rhizosphere functioning as they interact with both plants and soil microbial communities. The conditions in which AMF modify plant physiology and microbial communities in the rhizosphere are still poorly understood. In the present study, four different plant species, (clover, alfalfa, ryegrass, tall fescue) were cultivated in either sterilized (γ ray) or non-sterilized soil and either inoculated with a commercial AMF (Glomus LPA Val 1.) or not. After 20 weeks of cultivation, the mycorrhizal rate and shoot and root biomasses were measured. The abundance and composition of bacteria, archaea, and fungi were analyzed, respectively, by quantitative PCR (qPCR) and fingerprinting techniques. Whilst sterilization did not change the AMF capacity to modify plant biomass, significant changes in microbial communities were observed, depending on the taxon and the associated plant. AMF inoculation decreases both bacterial and archaeal abundance and diversity, with a greatest extent in sterilized samples. These results also show that AMF exert different selections on soil microbial communities according to the plant species they are associated with. This study suggests that the initial abundance and diversity of rhizosphere microbial communities should be considered when introducing AMF to cultures.

中文翻译：

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初始微生物状态调节菌根接种对根际微生物群落的影响。

丛枝菌根真菌（AMF）在根际功能中起着重要作用，因为它们与植物和土壤微生物群落相互作用。AMF改变根际中植物生理和微生物群落的条件仍然知之甚少。在本研究中，在灭菌（γ射线）或未灭菌的土壤中种植了四种不同的植物物种（三叶草，苜蓿，黑麦草，高羊茅），并用商业AMF（Glomus LPA Val 1）进行了接种。） 或不。培养20周后，测定菌根率以及枝条和根生物量。通过定量PCR（qPCR）和指纹技术分别分析了细菌，古细菌和真菌的丰度和组成。尽管灭菌未改变AMF修饰植物生物量的能力，但根据分类群和相关植物，观察到微生物群落发生了显着变化。AMF接种会最大程度地减少无菌样品中细菌和古细菌的丰度和多样性。这些结果还表明，AMF根据与之相关的植物种类对土壤微生物群落进行不同的选择。