Abstract: [Objective] The purpose of this paper was to investigate characteristics of the soil fungal diversities and community structures in dry and wet seasons under different waterlogging conditions in Napahai plateau wetland, in order to provide data support for understanding the ecological mechanisms of soil microbial during the process of plateau wetland degradation and provide data and theoretical basis for the protection and restoration of plateau wetland.[Method] Three typical wetlands (swamp wetland with perennial waterlogging SWPW, swamp meadow with seasonal waterlogging SMSW and meadow without waterlogging MW) under different waterlogging conditions in Napahai wetland were targeted. We used high-throughput sequencing technology to study dynamic characteristics of soil fungi community in dry and wet seasons, and we applied RDA analysis to explore effects of soil physical and chemical properties on soil fungal diversities and community structures caused by different water conditions.[Result] 1) We found soil fungi totally 54 genera in 29 classes and 5 phylum of soil fungi by high-throughput sequencing, and waterlogging conditions significantly influenced the composition and structure of soil fungi. With the decrease in waterlogging condition of the wetland soil, the soil fungi composition shifted from unclassified fungi to Ascomycota, the abundance of unclassified fungi decreased from 85.26% and 66.27% to 5.63% and 6.43% in dry season and wet season, respectively, while the abundance of Ascomycota increased from 9.9% and 10.57% to 71.11% and 52.07%, respectively. From the dry season to the wet season, unclassified fungi decreased and classified fungi increased in Napahai, with the dominant fungi classes increased from 6 to 8. 2) There was a significant difference in fungi community diversity between different waterlogging conditions (P<0.05) and between dry and wet seasons (P<0.05). The diversity of MW was significantly higher than that of SWPW and SMSW, and higher diversity was presented in the wet season than in the dry season, particularly for SMSW. 3) Waterlogging conditions significantly affected soil physical and chemical properties of plateau wetland (P<0.05). In both dry and wet seasons, soil organic matter, TN, water content, AN, and TK were featured with the tendency of the highest portion in the SWPW, seconded by that in SMSW, and the lowest in MW, and content of those substance were higher in the wet season than that in the dry season.4) RDA and Pearson correlation analysis showed that water content, organic matter, TN and AN and TK were the main factors that significantly influenced soil fungi community structures in dry and wet seasons under different waterlogging conditions.[Conclusion] Wetland hydrological changes caused by drainage significantly changed the wetland soil physical and chemical properties, which led to changes in the composition, structure and diversity of soil fungi. The results would provide scientific evidence for the study of soil microbial structure and its ecological process in the degraded plateau wetland.

Key words: Napahai plateau wetland, waterlogging condition, fungi community structure, high-throughput sequencing