Soil Fungal Diversity And Phylogenetic Analysis Of Dominant Taxa In Sichuan And Chongqing

Soil fungi exist widely in soil and are one of the most abundant and diverse fungal groups on earth.They play an important role in terrestrial ecosystems.They are decomposers of the ecosystem and participate in the carbon cycle.Soil fungi are also pathogens and mutualistic symbionts of plants and animals.Soil fungi play an important role in the healthy growth of horticultural crops including vegetables and edible fungi.The study of soil fungi is the basis for the prevention and identification of fungal diseases in vegetables,and provides basic information for the prevention of fungal diseases occurred in vegetables and promotes the healthy and stable development of vegetable horticulture industry.At the same time,it also provides basic information for local soil fungal ecology and biogeographic information.Sichuan and Chongqing region has a subtropical monsoon climate,humid and hot all the year round,which is conducive to the propagation of soil fungi.At present,soil fungi have not been described in most areas,and the mycorrhizal fungi,biocontrol fungi and pathogenic fungi in soil play a significant role in the stability of the ecosystem in this region,so it has important theoretical and practical significance for the study of soil fungi in Chongqing,Sichuan province.In this study,33 soil samples from some areas of Sichuan and Chongqing were used as experimental materials to study the isolation,molecular and morphological identification,diversity study and phylogenetic analysis of dominant groups of soil fungi,so as to explore the diversity information of soil fungi.At the same time,systematic morphological identification of representative fungi and phylogenetic analysis of dominant groups were carried out.The main results of this paper are as follows:1.A total of 669 culturable fungi were isolated from 33 soil samples.According to the molecular identification of ITS fragments,there were 221 species belonging to 70 genera.It was found that most isolated soil fungi belonged to Ascomycota,accounting for 83.86% of all isolated fungi.Eurotiomycetes and Eurotiales were the most dominant taxa,accounting for 41.40% of the total.At the family level,Aspergillaceae was the dominant group 39.46%.At genus level,Penicillium was found to be the most dominant genus accounting for 33.63%,common vegetable pathogenic fungi,such as Trichoderma 9.57%,Fusarium 8.97%,Mortierella 5.98%,Mucor 5.83%,Aspergillus was 5.83%,which was also the dominant group in isolation.2.In order to identify the isolated fungi from morphology,12 strains(including 10 dominant group fungi and 2 non-dominant group fungi)were selected for morphological classification and description.It was found that the morphological characteristics of the isolated species were basically the same as those of the molecular identified species.3.The phylogenetic trees of Penicillium,Aspergillus and Mucor were constructed by using ITS,Ca M,Ben A and RPB2,revealing evolutionary relationships.4.Two new species of Talaromyces fungi,Talaromyces chongqingensis sp.nov.and Talaromyces wushanicus sp.nov.,were described.The morphological description of two suspected new species of Mucor and Gongronella respectively was carried out.