title: The phylogeny of Porinaceae (Ostropomycetidae) suggests a neotenic origin of perithecia in Lecanoromycetes.
abstract: The family Porinaceae (Trichotheliales) is characterized by perithecial ascomata of ascohymenial origin. The phylogenetic position of this family in the system of ascomycetes has been uncertain and is investigated using mtSSU rDNA sequences. The dataset consists of lichenized representatives of major ascomycete lineages, including those that were previously suspected as relatives of Porinaceae, such as Pyrenulaceae. The dataset was subjected to a Bayesian phylogenetic analysis implementing a Metropolis Coupled Markov Chain Monte Carlo method. The analysis confirms previous classification of the apothecial Gomphillaceae near to Graphidaceae, and suggests that the pyrenocarpous Porinaceae are also close to Graphidaceae, Gyalectaceae, and Stictidaceae. The subclass Ostropomycetidae is here suggested to include the families Gomphillaceae, Gyalectaceae, Graphidaceae (incl. Thelotremataceae), Porinaceae, and Stictidaceae. A special type of hemiangiocarpous ontogeny of the ascomata is shared throughout the Ostropomycetidae, and the closed fruit bodies of Porinaceae are apparently a result of a neotenic ontogeny. This is associated with special hymenial characters: rather thin-walled narrow asci, and a different consistency of the hymenial gels.
authors.affiliation: Institute for Plant Sciences, University Graz, Holteigasse 6, A-8010 Graz, Austria. martin.grube@uni-graz.at
authors.forename: Martin
authors.initials: M
authors.lastname: Grube
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Baloch
authors.forename: H Thorsten
authors.initials: HT
authors.lastname: Lumbsch
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000235:genetics* / Q000648:ultrastructure; D001483:Base Sequence; D001499:Bayes Theorem; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D008011:Lichens / Q000145:classification / Q000235:genetics* / Q000648:ultrastructure; D008390:Markov Chains; D008969:Molecular Sequence Data; D009010:Monte Carlo Method; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal