The Study Of Endophytic Fungi Of Aquatic Plant And Its Sediment Fungidiversity

At present,most research of endophytic fungi are focused on terrestrial plants.Endophytic fungi of aquatic plant and its sediment fungi play an important role in freshwater aquatic ecosystems,but the research is very few on these fungi.In the study,the methods including culture and culture-independent were used to research the endophytic fungi of aquatic plants and sediment fungi in Sichuan and Yunnan provinces,to explore the diversity and community composition of them.And also,the factors were analyzed thatcaused the difference of the community composition.The following research results are obtained:1.The results of the study on the diversity of endophytic fungi in twenty samples of aquatic plants were show that 75.81%of them can only be identified to the fungi,and the rest of them are belong to 6 phylums(Ascomycota?Basidiomycota?Zygomycota?Chytridiomycota?Glomeromycota and Rozellomycota),18 classes,50 orders,91 families and 91 genera.The endophytic fungi,which are detected by each category,are about twice as likely to be cultured.The Chytridiomycota,Glomeromycota and Rozellomycota can be detected by culture-independent,but can't be isolated by culture.And the fungi,which are belong to Myxomycetes,3 orders,6 families and 21 genera,were isolated by the methotd of culture,and they weren't detectedby the method of high-throughput sequencing.The results show that the union of two methods can be more objective in the investigation of fungal diversity.Using the same technique to study the sediment fungi,12.61%of them can not be identified to any fungi taxon,and the rest of them are belong to 6 phylums,24 classes,89 orders,207 families and 364 genera by the sequence alignment analysis.By culture-independent,the fungi,which belong to 3 phylums(Chytridiomycota?Glomeromycota and Neocallimastigomycota),19 classes,72 orders,169 families and 349 genera,can be detected,but they weren't isolated byculture.The types and quantities of fungi in the sediment samples are significantly higher than those in aquatic plants.And there is a significant difference on diversity and composition between the fungi in aquatic plants and sediment.75.1%of endophytic fungi of aquatic plant,which obtained by the method of culture-independent,can not be identified to any phylum.And only 12.61%of the sediment fungi can not be identified to any phylum.It shows that there is a huge diversity of fungi in the aquatic plant tissue.2.Similarity analysis of the fungal community:and it can be found that there are only 18 OUTs in the 5 samples of Batrachium bungei from 5 plots with different elevation by Venn analysis.They areXiajisha(3275m),Kasa lake2(3505m),Luhuo(3886m),Wuliang river(3992m)and Daocheng5(4.853m).There are 401 OTUs on the samples fromWuliang river and Kasa lake2.The OUTs are the most,and it shows that the composition of the endophytic fungi in aquatic plants is mainly influenced by the environment,not the host itself.The endophytic fungi of Myriophyllum spicatum,Hippuris Vulgaris andBatrachium bungei are shared of 180TUs.The OUTs of Myriophyllum spicatumare 133,and it's 22 of Hippuris Vulgaris,545 of Batrachium bungei.The results show that there is lots of difference in endophytic fungi of different aquatic plants at the same elevation.By analysis of thesediment fungi in four plots with different elevation(Daofu with 2975m,Kasa lake2 with 3505m,Luhuo with 3886m,Xiajisha with 3275m),it can be found that they are shared of 122 OTUs,and there are more unique OTUs of them.The results show that the fungi in different sediment samples are different.Four sediment samples(Daocheng5,Daofu,Laobaoteng and Xiajisha)with pH 7.13?7.37 were analysed,and it can be found that it's not linear relationship between pH and the mutual or unique OUTs.The results show that it is not only the pH that leads to the differentiation of thesediment fungi.3.Species diversity analysis:The results of the culture-independent show that the fungal diversity of aquatic plant samples from Wuliang river and Kasa lake2 is significantly higher than other samples in the same aquatic plantBatrachium bungei.For the same lake and the same plant,the fungal diversity of leaves is higher than others.For the sediment samples,the fungal diversity of sediment samples from Daocheng5 and Luhuo is basically the same,but they are lower than other samples,the fungal diversity in sample of Daofu is the most abundant.