Abstract: This study investigated the fungal community structure and diversity in Namtso Lake during spring using high-throughput sequencing technology. The results showed that a total of 5791 OTUs were obtained from 20 sampling sites, which were classified into 17 phyla, 65 classes, 168 orders, 403 families and 869 genera by annotation. The dominant fungal communities were Ascomycota, Basidiomycota, and Mortierellaomycota. The α-diversity indices showed that the Shannon and Simpson diversity indices across the 20 sampling sites ranged from 2.01 to 7.10 and 0.39 to 0.98, respectively, while the Chao1 and ACE richness indices ranged from 672.51 to 1915.64 and 714.59 to 1920.35, respectively. PCoA and UPGMA cluster analyses indicated that the 20 sampling sites were grouped into four clusters, with the fungal community structures in the southwestern and northwestern regions exhibiting higher similarity. CCA results demonstrated that total dissolved solids (TDS), total phosphorus (TP), and turbidity were the key physicochemical factors significantly affecting the fungal community structure (P<0.05). The study explored the fungal community composition, diversity and their response to aquatic physicochemical factors in Namtso Lake, which provided a theoretical foundation for the utilization of fungal resources in lake and the protection of lake ecosystems in the Tibetan Plateau.

Key words: fungi, community structure, diversity, environmental factors, Namtso Lake