Objective To clarify the taxonomic status of AMF spores under the oak forest in the subalpine belt of the Hengduan Mountains.

Method Six samples of alpine oak root enclosures and root systems were selected from different parts of the subalpine belt of the Hengduan Mountains, and AMF spores in the soil were selected by wet sieving sedimentation method. AMF-specific primers were used to amplify the 18S rRNA gene of the ITS region, which was identified by combining morphological and molecular biological means, and the phylogenetic relationships were constructed to infer their affinities.

Result The results showed that AMF spores and root cloning consequences of alpine oak in Sichuan and Tibet were the genus Paraglomus. And the consequence of AMF cloning on the root surface and the AMF in soil of alpine oak in Shangri-La showed that AMF could exist in the inter-roots of alpine oak plants. These AMF were the genus Glomus. In addition, only one AMF was found in the root envelope and inter-root soil of alpine oak forest in different sampling sites, suggesting that AMF might have a symbiotic relationship with alpine oak. Aniline blue pigment staining result showed obvious arbuscular and vesicle structures in roots. In addition, the AMF spores under the Alpine oak forest differentiated during the evolution and were between the taxonomic status of Paraglomus and Glomus, and there were differences in AMF in Tibet, Sichuan and Shangri-La, Yunnan.

Conclusion AMF generally exists in the pure understory root rhizosphere and inter-root soil of alpine oak in the subalpine belt of the Hengduan Mountains, which provides a theoretical reference for understanding the formation and evolution of AMF in the understory of alpine oak in the subalpine belt of the Hengduan Mountains