Diversity Of Aquatic Fungi And Its Relationship With Environmental Factors In Cangshan Streams

Objective: To discover and describe the taxa of aquatic fungi in Cangshan streams,study the species diversity and community structure of this type of fungi,and further clarify the relationship between fungal diversity and community structure and the environmental factors: water body,season,altitude and vegetation.Method: Cangshan mountain was taken as the research area.From the six streams(Heilongtan,Jinxi,Lingquan,mocan,Wanhua and Yangxi)in Cangshan mountain samples were collected at an altitude ranging from 1900 to 3900 m in spring,summer,autumn and winter.Each sampling spot was 300 m apart.Combining the random sampling of natural substrates and the bait collection method of dominant tree species of shore vegetation,3240 submerged rotten woods were collected.Aquatic fungi were separated and identified with morphology and molecular systems.The Shannon-Wiener index was used to analyze the diversity of aquatic fungi in Cangshan streams,community similarity and their relationship with the environmental factors.Results: 1.From the 3240 samples,217 aquatic fungal strains were isolated and purified.115 genera and 141 species were identified including 3 new species.Acrogenospora sphaerocephala,Conioscypha aquatica,Cylindrodendrum album,Sporidesmiella hyalosperma,Stachybotrys chartarum,Thelonectria discophora,Thelonectria westlandica and Volutella ciliata were common genera and species.2.The diversity index of aquatic fungi from the six streams in the Cangshan mountain(Heilongtan,Jinxi,Lingquanxi,Mocanxi,Wanhuaxi and Yangxi)were2.65,3.00,3.93,3.38,3.20 and 2.89,which means Ling Quanxi had the highest species diversity.3.The species diversity of aquatic fungi was the highest in summer,the lowest in winter,and the community similarity was the highest between spring and summer(S?=0.125).the species diversity was the highest at 1900?2300m.As the altitude rises,the species diversity also shows an upward trend.The community similarity was the highest between middle-low and middle altitude(S?=0.165);the species diversity and detection rate on the natural substrate were the highest,and the community similarity index between the fixed bait and the natural substrate was lower.There were significant differences in species diversity.4.The latest phylogenetic tree of the genus Minimelanolocus was constructed,and two new species of the genus,M.clavatus and M.nujiangensis,were introduced.Conclusion: This study established a unified quantitative research method through the quantitative bait method,and the resources,diversity,community structure of aquatic fungi in Cangshan mountain and the relationship between them and environmental factors were first systematically studied and this study has enriched the resources bank of aquatic fungi,and the living habits of aquatic fungi were further undertood,which is the foundation for research on aquatic fungi in depth.