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 i...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 t展开更多
When hybridization results in reduced fitness, natural selection is expected to favor the evolution of traits that minimize the likelihood of hybridizing in the first place. This process, termed reinforcement （or, mo...When hybridization results in reduced fitness, natural selection is expected to favor the evolution of traits that minimize the likelihood of hybridizing in the first place. This process, termed reinforcement （or, more generally, reproductive character displacement）, thereby contributes to the evolution of enhanced reproductive isolation between hybridizing groups. By enhancing reproductive isolation in this way, reinforcement plays an important role in the final stages of speciation. However, reinforcement can also contribute to the early stages of speciation. Specifically, because selection to avoid hybridization occurs only in sympatric populations, the unfolding of reinforcement can lead to the evolution of traits in sympatric populations that reduce reproduction between conspecifics in sympatry versus those in allopatry. Thus, reinforcement between species can lead to reproductive isolation--and possibly speciation-between populations in sympatry versus those in allopatry or among different sympatric populations. Here, I describe how this process can occur, the conditions under which it is most likely to occur, and the empirical data needed to evaluate the hypothesis that reinforcement can initiate speciation.展开更多
文摘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 t
文摘When hybridization results in reduced fitness, natural selection is expected to favor the evolution of traits that minimize the likelihood of hybridizing in the first place. This process, termed reinforcement （or, more generally, reproductive character displacement）, thereby contributes to the evolution of enhanced reproductive isolation between hybridizing groups. By enhancing reproductive isolation in this way, reinforcement plays an important role in the final stages of speciation. However, reinforcement can also contribute to the early stages of speciation. Specifically, because selection to avoid hybridization occurs only in sympatric populations, the unfolding of reinforcement can lead to the evolution of traits in sympatric populations that reduce reproduction between conspecifics in sympatry versus those in allopatry. Thus, reinforcement between species can lead to reproductive isolation--and possibly speciation-between populations in sympatry versus those in allopatry or among different sympatric populations. Here, I describe how this process can occur, the conditions under which it is most likely to occur, and the empirical data needed to evaluate the hypothesis that reinforcement can initiate speciation.
