Objective In order to solve the problem of poor growth of Monoctasma savatieri in artificial cultivation compared with wild habitats, the reason for poor growth in artificial cultivation was explored from the perspective of rhizosphere soil fungi.

Method Study subjects were fungi in rhizosphere soil of Monochasma savatieri in one artificially cultivated habitat and three wild habitats, namely Camellia oleifera forest, Gardenia jasminoides forest, and Pinus massoniana plantation. A field survey, ITS high-throughput sequencing, RDA, Mantel analysis were conducted to compare the population characteristics of fungi in rhizosphere soil of Monochasma savatieri.

Result A total of 15 phyla, 50 classes, 139 orders, 299 families, and 644 genera of fungi were detected in the rhizosphere soil of Monochasma savatieri in the four habitats, with the dominant phyla being Ascomycota and Basidiomycota. There were a total of 27 dominant genera. The dominant fungal genus in rhizosphere soil of Monochasma savatieri under Pinus massoniana plantation and Camellia oleifera forest was Archaeorhizomyces, while the dominant fungal genus in rhizosphere soil of Gardenia jasminoides forest was Saitozyma. Under artificial cultivation conditions, the dominant fungal genus was Leucoagaricus. There were significant differences between fungal community structures of rhizosphere soil of Monochasma savatieri under artificial cultivation and wild habitats (Gardenia jasminoides forest, Camellia oleifera forest, and Pinus massoniana plantation). And its richness index (Chao1 index) was significantly lower than that of Gardenia jasminoides habitat. The fungal community structure was mainly affected by alkali-hydrolysable nitrogen and organic matter in soil, and alkali-hydrolysable nitrogen was also a major environmental factor affecting genus Leucoagaricus.

Conclusion There is a significant difference in composition of soil fungal communities between cultivated and wild habitats of Monochasma savatier. The fungal community structure is mainly affected by alkali-hydrolysable nitrogen and organic matter in soil. So the growth of Monochasma savatieri can be regulated by measures such as applying nitrogen fertilizer.