Habitat ecological characteristics and soil fungal community structure of Paphiopedilum subgenus Brachypetalum Hallier (Orchidaceae) plants in Southwest China

Species of the subgenus Brachypetalum are the most primitive, most ornamental and most threatened group in the Orchid. This study revealed the ecological characteristics, soil nutrient characteristics and soil fungal community structure of habitats of the subgenus Brachypetalum in Southwest China. Lays a foundation for research on the wild populations and conservation Brachypetalum. The results showed that species of the subgenus Brachypetalum preferred a cool and humid environment, grew in scattered or aggregated form in narrow negative terrain, mainly in humic soil. The soil physical and chemical properties and soil enzyme activity indexes of the habitats were significantly different among different species, and the soil properties of different distribution points of the same species also varied greatly. There were significant differences in the soil fungal community structure among the habitats of different species. Basidiomycetes and ascomycetes were the main fungi in habitats of subgenus Brachypetalum species, and their relative abundance varied among different species. The functional groups of soil fungi were mainly symbiotic fungi and saprophytic fungi. LEfSe analysis found that there were different numbers and species of biomarkers in the habitats of subgenus Brachypetalum species, indicating that the habitat preference characteristics of each species in subgenus Brachypetalum were reflected in the fungal community. It was found that environmental factors had an impact on the changes in soil fungal communities in the habitats of subgenus Brachypetalum species, with climatic factors having the highest explanation rate (20.96%). Soil properties were significantly positively or negatively correlated with a variety of dominant soil fungal groups. Conclusions: The results of this study lay the foundation for the study of the habitat characteristics of wild populations of subgenus Brachypetalum and provides data to support in situ and ex situ conservation in the future.