Abstract
Arbuscular mycorrhizal (AM) fungi play vital roles in promoting tree growth and maintaining biodiversity and ecosystem stability in subtropical forests. Phoebe bournei, a key species endemic to the subtropical evergreen broad-leaved forests of China, forms symbiosis associations with AM fungi. However, the composition and structure of AM fungal communities associated with naturally regenerated P. bournei remain insufficiently characterized. This study used Illumina MiSeq sequencing to investigate the AM fungal communities in the root and rhizosphere soil samples. In total, 305 operational taxonomic units (OTUs) belonging to four orders and seven families were uncovered within Glomeromycota. Seven and nine AM fungal genera were detected in root and rhizosphere soil samples, respectively, with Glomus being the most dominant genus in both root and rhizosphere soil samples. Moreover, the diversity of AM fungal communities varied across sampling locations in the rhizosphere soil and roots. The co-occurrence network structure of the AM fungal community in the rhizosphere soil was more complex and robust than that of the roots. Furthermore, soil properties, latitude, and altitude influenced the changes in AM fungal α-diversity and the relative abundance of genera in roots and rhizosphere soil to varying degrees. Overall, our findings highlight the pivotal role of soil properties over geographical variables in explaining variations in the AM fungal community structure, with soil properties-particularly total phosphorus and total nitrogen-markedly driving the AM fungal community structure in the rhizosphere soil and roots of naturally regenerated P. bournei seedlings.IMPORTANCEAlthough subtropical forest ecosystems harbor rich arbuscular mycorrhizal (AM) fungal resources, insights into their communities in the rhizosphere of Phoebe bournei remain limited. This study investigates the composition and key drivers of AM fungi communities in the rhizosphere soil and roots of naturally regenerated P. bournei seedlings in Guizhou, subtropical China. The findings deepen the understanding of the potential of AM fungi in supporting the establishment and growth of mycorrhizal plants, as well as maintaining the diversity, productivity, and stability of subtropical forest ecosystems. Moreover, this study provides valuable insights into the selection and application of AM fungi resources in mycorrhizal seedling cultivation and afforestation of P. bournei.