Diversity Distribution Pattern and Maintenance Mechanism of Epiphytic Fungi Communities on Leaves of Nymphaea tetragona and Vallisneria natans
In order to explore the diversity distribution pattern and maintenance mechanism of epiphytic fungi communities on leaf surfaces of different aquatic plants in wetland,this paper took epiphytic fungi communities on leaf surfaces of the dominant aquatic plants Nymphaea tetragona and Vallisneria natans,and planktonic fungi communities in Yuguqiao constructed wetland as the re-search objects.High-throughput sequencing was used to study the leaf surface epiphytic fungal communities of N.tetragona and V.natans in Yuguqiao constructed wetland,and the composition,diversity and maintenance mechanism of fungal communities under different environmental gradients were comparatively analyzed.The results show that epiphytic and planktonic fungi communities are different in species composition at the phylum and genus levels,and most of them are saprophytic and pathogenic fungi.The Sobs index and Chao index of planktonic fungi are significantly lower than epiphytic fungi communities of N.tetragona and V.na-tans,while there is no significant difference in Shannon index and Simpson index among them.PCoA analysis shows that there is significant spatial heterogeneity between the epiphytic fungi communities on leaves of N.tetragona and V.natans and the planktonic fungi communities.RDA analysis shows that dissolved oxygen(DO),salinity(SAL)and ammonium ion(NH4+)are significantly cor-related with the spatial distribution of fungi communities.Null model analysis shows that deterministic processes are dominant in the construction of fungi communities in different habitats.Co-occurrence network analysis shows that there is more competition in the planktonic communities,and the network is more complex and stable.The results of FUNGuild function prediction shows that there are a large number of pathogens and saprophytes in the epiphytic fungi communities of aquatic plants.In conclusion,the re-sults of this study reveal the distribution pattern and maintenance mechanism of epiphytic fungi communities diversity in different aquatic plants.