Abstract: Woonyoungia septentrionalis is an endangered dioecious species in China and mainly distributed in the karst habitats. Soil fungi affect the growth, development and morphogenesis of male and female trees, as well as their interaction with neighbors. Studying the difference in the composition and diversity of rhizosphere soil fungi between male and female Woonyoungia septentrionalis can provide theoretical basis for revealing the maintenance mechanism of their population in diverse habitats of karst regions. Based on the sequencing platform of PacBio, single molecule real-time sequencing (SMRT Cell) was used to investigate the composition and diversity of fungal communities in the rhizosphere soil of female and male Woonyoungia septentrionalis in Guizhou Maolan National Nature Reserve and Guangxi Mulun National Nature Reserve. The results showed that: (1) A total of 2375 fungal amplicon sequence variants (ASVs) were obtained from soil samples, belonging to 8 phyla, 30 classes, 83 orders, 176 families and 344 genera. At the phylum level, Ascomycota, Basidiomycota and Rozellomycota were the dominant phyla in the female and male individuals of Woonyoungia septentrionalis, but the relative abundances of Basidiomycota in female Woonyoungia septentrionalis were significantly higher than those in male Woonyoungia septentrionalis, while the relative abundances of Ascomycota and Rozellomycota were lower than those in male Woonyoungia septentrionalis. There were significant differences in the abundance of Pleosporales, Pezizales, and Tetracladium between the male and female groups. (2) NMDS analysis showed that there were significant differences in fungal structure between male and female groups. (3) There was no significant difference in rhizosphere soil fungi diversity index (Chao1, ACE, Shannon and Simpson) between female and male Woonyoungia septentrionalis (P>0.05). The faith_pd index of rhizosphere soil fungi in Woonyoungia septentrionalis of Guangxi was significantly lower than that in Guizhou.

Key words: Woonyoungia septentrionalis, soil fungi, fungal community diversity, rare and endangered plant, dioecy, karst habitat