Trapelioid fungi constitute a widespread group of mostly crust-forming lichen mycobionts that are key to understanding the early evolutionary splits in the Ostropomycetidae,the second-most species-rich subclass of lic...Trapelioid fungi constitute a widespread group of mostly crust-forming lichen mycobionts that are key to understanding the early evolutionary splits in the Ostropomycetidae,the second-most species-rich subclass of lichenized Ascomycota.The uncertain phylogenetic resolution of the approximately 170 species referred to this group contributes to a poorly resolved backbone for the entire subclass.Based on a data set including 657 newly generated sequences from four ribosomal and four protein-coding gene loci,we tested a series of a priori and new evolutionary hypotheses regarding the relationships of trapelioid clades within Ostropomycetidae.We found strong support for a monophyletic group of nine core trapelioid genera but no statistical support to reject the long-standing hypothesis that trapelioid genera are sister to Baeomycetaceae or Hymeneliaceae.However,we can reject a sister group relationship to Ostropales with high confidence.Our data also shed light on several longstanding questions,recovering Anamylopsoraceae nested within Baeomycetaceae,elucidating two major monophyletic groups within trapelioids(recognized here as Trapeliaceae and Xylographaceae),and rejecting the monophyly of the genus Rimularia.We transfer eleven species of the latter genus to Lambiella and describe the genus Parainoa to accommodate a previously misunderstood species of Trapeliopsis.Past phylogenetic studies in Ostropomycetidae have invoked Bdivergence order^for drawing taxonomic conclusions on higher level taxa.Our data show that if backbone support is lacking,contrasting solutions may be recovered with different or added data.We accordingly urge caution in concluding evolutionary relationships from unresolved phylogenies.展开更多
Understanding how many species exist and the processes by which they form remains a central topic of ecological and evolutionary biology,but represents a special challenge within microbial groups.The lichen-forming fu...Understanding how many species exist and the processes by which they form remains a central topic of ecological and evolutionary biology,but represents a special challenge within microbial groups.The lichen-forming fungi represent one of the best examples in which species evolution and diversity create patterns of high phenotypic plasticity coupled with wide geographic distributions.We sampled the lichen-forming species Tephromela atra and related species at a world-wide scale to reconstruct a phylogenetic hypothesis using three nuclear markers.Samples were also studied for morphological and chemical traits to assess how well the phenotypic relationships with species,previously segregated from T.atra,agrees with molecular data.We used a genealogical concordance approach and identified 15 monophyletic clades,which may represent independent lineages.By combining morphological and chemical characters,ecological preferences and geographic origin we distinguish six different species.Although subtle phenotypical traits are frequently used for describing previously cryptic species in fungi,the continuum of variability found in morphology and chemical patterns in T.atra prevents the description of new taxa with characteristic traits.We observed that phenotypic characters arise in parallel at local or regional scale but are not correlated with genetic isolation.Therefore,they are insufficient for characterizing species with broad geographic ranges within T.atra.展开更多
基金We would like to thank the numerous individuals who provided specimens for DNA sequencing for this study,including A.Acton,A.Aptroot,C.Björk,B.Coppins,G.Kantvilas,J.McCarthy,B.McCune,L.Muggia,O.Peksa,S.Pérez-Ortega,T.Tønsberg,P.van den Boom and the curators of F,GZU,O and UPS.Thanks go to Walter Obermayer,Graz,for performing thin layer chromatography on several specimens.Fernando Fernández-Mendoza and Martin Grube provided helpful comments at earlier stages of this project.We also thank Joseph Ryan for help with troubleshooting the SOWHAT analyses.DNA sequencing of Alaskan specimens was funded in part by a materials contribution from the Tongass National Forest,U.S.Department of Agriculture,courtesy of K.Dillman,for which we are grateful.The project was funded by the Austrian Science Foundation(FWF grant P25237,BEvolution of Substrate Specificity in Lichens^).The work by MW was financed by the Swedish Taxonomy Initiative(Svenska Artprojektet,administered by the Swedish Species Information Centre/ArtDatabanken).CP gratefully acknowledges financial support through the program BLOEWE-LandesOffensive zur Entwicklung wissenschaftlich-ökonomischer Exzellenz^of the Hessen Ministry of Higher Education,Research,and the Arts.ZP thanks for the support by the Czech Academy of Science(AV0Z60050516,RVO 67985939)and the Minsitry of Education,Youth and Sports of the Czech Republic.
文摘Trapelioid fungi constitute a widespread group of mostly crust-forming lichen mycobionts that are key to understanding the early evolutionary splits in the Ostropomycetidae,the second-most species-rich subclass of lichenized Ascomycota.The uncertain phylogenetic resolution of the approximately 170 species referred to this group contributes to a poorly resolved backbone for the entire subclass.Based on a data set including 657 newly generated sequences from four ribosomal and four protein-coding gene loci,we tested a series of a priori and new evolutionary hypotheses regarding the relationships of trapelioid clades within Ostropomycetidae.We found strong support for a monophyletic group of nine core trapelioid genera but no statistical support to reject the long-standing hypothesis that trapelioid genera are sister to Baeomycetaceae or Hymeneliaceae.However,we can reject a sister group relationship to Ostropales with high confidence.Our data also shed light on several longstanding questions,recovering Anamylopsoraceae nested within Baeomycetaceae,elucidating two major monophyletic groups within trapelioids(recognized here as Trapeliaceae and Xylographaceae),and rejecting the monophyly of the genus Rimularia.We transfer eleven species of the latter genus to Lambiella and describe the genus Parainoa to accommodate a previously misunderstood species of Trapeliopsis.Past phylogenetic studies in Ostropomycetidae have invoked Bdivergence order^for drawing taxonomic conclusions on higher level taxa.Our data show that if backbone support is lacking,contrasting solutions may be recovered with different or added data.We accordingly urge caution in concluding evolutionary relationships from unresolved phylogenies.
基金LM,MG and TS are grateful to the Austrian Science Foundation for financial support(LM for FWF Herta-Firnberg Project T481-B20,TS for FWF P25237)SPO is supported by the grant CTM2012-38222-C02-02 from the Spanish Ministry of Economy and Competitiveness.Program.
文摘Understanding how many species exist and the processes by which they form remains a central topic of ecological and evolutionary biology,but represents a special challenge within microbial groups.The lichen-forming fungi represent one of the best examples in which species evolution and diversity create patterns of high phenotypic plasticity coupled with wide geographic distributions.We sampled the lichen-forming species Tephromela atra and related species at a world-wide scale to reconstruct a phylogenetic hypothesis using three nuclear markers.Samples were also studied for morphological and chemical traits to assess how well the phenotypic relationships with species,previously segregated from T.atra,agrees with molecular data.We used a genealogical concordance approach and identified 15 monophyletic clades,which may represent independent lineages.By combining morphological and chemical characters,ecological preferences and geographic origin we distinguish six different species.Although subtle phenotypical traits are frequently used for describing previously cryptic species in fungi,the continuum of variability found in morphology and chemical patterns in T.atra prevents the description of new taxa with characteristic traits.We observed that phenotypic characters arise in parallel at local or regional scale but are not correlated with genetic isolation.Therefore,they are insufficient for characterizing species with broad geographic ranges within T.atra.
