title: Diagnostics for a troubled backbone: testing topological hypotheses of trapelioid lichenized fungi in a large-scale phylogeny of Ostropomycetidae (Lecanoromycetes).
abstract: 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 long-standing 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 genusRimularia. We transfer eleven species of the latter genus toLambiellaand describe the genusParainoato accommodate a previously misunderstood species ofTrapeliopsis. Past phylogenetic studies in Ostropomycetidae have invoked "divergence 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.
authors: Institute of Plant Sciences, NAWI Graz, University of Graz, Holteigasse 6, A-8010 Graz, Austria.
authors: Philipp
authors: P
authors: Resl
authors: Institute of Plant Sciences, NAWI Graz, University of Graz, Holteigasse 6, A-8010 Graz, Austria.
authors: Kevin
authors: K
authors: Schneider
authors: Department of Botany, Swedish Museum of Natural History, P.O. Box 50007, SE-104 05 Stockholm, Sweden.
authors: Martin
authors: M
authors: Westberg
authors: Senckenberg Forschungsinstitut und Naturmuseum, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany.
authors: Christian
authors: C
authors: Printzen
authors: Institute of Botany, Academy of Sciences of the Czech Republic, Zámek 1, 252 43 Průhonice, Czech Republic ; Department of Botany, Faculty of Sciences, Charles University in Prague, Benátská 2, 128 01 Praha 2, Czech Republic.
authors: Zdeněk
authors: Z
authors: Palice
authors: Department of Ecology, Swedish University of Agricultural Sciences, P. O. Box 7044, SE-750 07 Uppsala, Sweden.
authors: Göran
authors: G
authors: Thor
authors: Herbarium, Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA.
authors: Alan
authors: A
authors: Fryday
authors: Institute of Plant Sciences, NAWI Graz, University of Graz, Holteigasse 6, A-8010 Graz, Austria.
authors: Helmut
authors: H
authors: Mayrhofer
authors: Institute of Plant Sciences, NAWI Graz, University of Graz, Holteigasse 6, A-8010 Graz, Austria ; Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812 USA.
authors: Toby
authors: T
authors: Spribille
keywords: Ascomycota; Fungi; Lambiella; Lecanoromycetes; Ostropomycetidae; Parainoa; Paraphyly; SOWH test; Taxon sampling