摘要
Hypocreomycetidae is a highly diverse group with species from various habitats. This subclass has been reported as pathogenic,endophytic, parasitic, saprobic, fungicolous, lichenicolous, algicolous, coprophilous and insect fungi from aquatic andterrestrial habitats. In this study, we focused on freshwater fungi of Hypocreomycetidae which resulted 41 fresh collectionsfrom China and Thailand. Based on morphological and phylogenetic analyses, we identified 26 species that belong to twoorders (Hypocreales and Microascales) and six families (Bionectriaceae, Halosphaeriaceae, Microascaceae, Nectriaceae,Sarocladiaceae and Stachybotryaceae). Ten new species are introduced and 13 new habitats and geographic records arereported. Mariannaea superimposita, Stachybotrys chartarum and S. chlorohalonatus are recollected from freshwater habitatsin China. Based on phylogenetic analysis of combined LSU, ITS, SSU, rpb2 and tef1-α sequences data, Emericellopsisis transferred to Hypocreales genera incertae sedis;Pseudoacremonium is transferred to Bionectriaceae;Sedecimiella isplaced in Nectriaceae;Nautosphaeria and Tubakiella are excluded from Halosphaeriaceae and placed in Microascalesgenera incertae sedis;and Faurelina is excluded from Hypocreomycetidae. Varicosporella is placed under Atractium as asynonym of Atractium. In addition, phylogenetic analysis and divergence time estimates showed that Ascocodina, Campylospora,Cornuvesica and Xenodactylariaceae form distinct lineages in Hypocreomycetidae and they evolved in the family/order time frame. Hence, a new order (Xenodactylariales) and three new families (Ascocodinaceae, Campylosporaceae andCornuvesicaceae) are introduced based on phylogenetic analysis, divergence time estimations and morphological characters.Ancestral character state analysis is performed for different habitats of Hypocreomycetidae including freshwater, marineand terrestrial taxa. The result indicates that marine and freshwater fungi evolved independently from terrestrial ancestors.The results further support those early diverging clades of this subclass, mostly comprising terrestrial taxa and freshwaterand marine taxa have been secondarily derived, while the crown clade (Nectriaceae) is represented in all three habitats. Theevolution of various morphological adaptations towards their habitual changes are also discussed.
