Two new genera, Rhamphoriopsis and Xylolentia, are described for lignicolous perithecial ascomycetes occurring in terrestrial habitats. Fresh material, living cultures, morphology, and DNA sequence data (nuc rDNA internal transcribed spacers [ITS1-5.8S-ITS2 = ITS], 18S and 28S genes, and second largest subunit of RNA polymerase II = RPB2) of these taxa and morphologically similar fungi were studied to determine their relationships. A monophyletic clade including Rhamphoria, Rhodoveronaea, a dematiaceous hyphomycete Linkosia multiseptum, and the two new genera was recovered in the Sordariomycetes based on the 18S-28S-RPB2 data set. It is introduced as the family Rhamphoriaceae and strongly supported by Bayesian and maximum likelihood methods. Its members are characterized by perithecial ascomata with a cylindrical or rostrate neck, the absence of stromatic tissue or clypeus, similar anatomy of two-layered ascomatal walls, cylindrical paraphyses, unitunicate asci with a distinct, nonamyloid apical annulus, and dictyoseptate or transversely septate, hyaline or brown ascospores. The mode of conidiogenesis is holoblastic, predominantly on polyblastic-denticulate conidiogenous cells. The Phaeoisaria-like anamorph has been linked to Rhamphoria and Rhamphoriopsis, whereas conidia and conidiophores of Idriella-like synanamorph were formed in vitro in two species of Rhamphoria. The Veronaea-like anamorph is associated with Rhodoveronaea. The anamorph of Xylolentia is a dematiaceous hyphomycete with conidiogenous cells with sympodially extending rachis. A key to members of the family is provided. The classification and nature of species boundaries in Rhamphoria are discussed, and diagnostic characters such as ascospore shape, number of transverse and longitudinal septa, a degree of constriction at the septa, and ability to produce ascoconidia are evaluated.
- MeSH
- Ascomycota classification genetics isolation & purification MeSH
- Bayes Theorem MeSH
- DNA, Fungal genetics MeSH
- Ecosystem MeSH
- Phylogeny * MeSH
- Multigene Family MeSH
- DNA, Ribosomal MeSH
- RNA Polymerase II genetics MeSH
- Base Sequence MeSH
- Sequence Analysis, DNA MeSH
- Spores, Fungal classification MeSH
- Xylariales genetics MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The monotypic genus Xylochrysis is introduced for a lignicolous perithecial ascomycete that possesses golden yellow ascomata with black glabrous necks, a three-layered ascomatal wall, persistent paraphyses, and cylindrical, long-stipitate unitunicate asci with an inamyloid apical annulus, and hyaline, ellipsoidal, unicellular ascospores. In culture it produces hyaline conidiophores with terminally arranged branches bearing metulae, conidiogenous cells and holoblastic conidia. Phylogenetic analysis of two ribosomal (nc18S and nc28S rDNA) and one protein-coding (RPB2) gene position this species within the Sordariomycetidae but without close ordinal or familial affiliation. Morphological and molecular DNA data support the recognition of this new genus and suggest that Xylochrysis is most closely related to the genera Ceratolenta, Cyanoannulus and Woswasia.
- MeSH
- Ascomycota classification genetics growth & development isolation & purification MeSH
- DNA, Fungal genetics MeSH
- Wood microbiology MeSH
- Phylogeny MeSH
- Lignin metabolism MeSH
- Molecular Sequence Data MeSH
- DNA, Ribosomal genetics MeSH
- Spores, Fungal classification genetics growth & development isolation & purification MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Wood-inhabiting taxa of the Sordariomycetidae comprise several distantly related monotypic or small genera, which lack familial or ordinal affiliation and share a simple and inconspicuous morphology of dark ascomata with carbonaceous walls and long necks, stipitate asci and hyaline ellipsoidal, fusiform to cylindrical ascospores. Recent collections of an undescribed fungus and of Ceratosphaeria abietis reveal two additional evolutionary lineages characterized by this simple and indistinct teleomorph morphology. Phylogenetic analysis of three genes, small and large subunit nuclear ribosomal DNA (nc28S and nc18S rDNA) combined with the second largest subunit of RNA polymerase II (rpb2), supports the recognition of two new genera, Ceratolenta and Platytrachelon for C. abietis. Platytrachelon abietis is redescribed and illustrated based on additional collections. In culture it produced a dematiaceous hyphomycetous anamorph with blastic conidiogenesis and ellipsoidal, septate, pale brown conidia. It was associated with a synanamorph producing cylindrical, strongly curved hyaline conidia. Molecular data suggest a relationship of Platytrachelon with the Papulosaceae, while Ceratolenta forms a monophylum on a separate branch. Both taxonomic novelties possess striking morphological similarities with Ceratosphaeria, Lentomitella and Rhodoveronaea, which recently were reinstated based on DNA sequence data. A key to morphologically similar wood-inhabiting fungi classified in the Sordariomycetidae is provided.
- MeSH
- Ascomycota classification cytology genetics isolation & purification MeSH
- DNA, Fungal chemistry genetics MeSH
- Fungal Proteins genetics MeSH
- Phylogeny MeSH
- Molecular Sequence Data MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA Polymerase II genetics MeSH
- Base Sequence MeSH
- Sequence Analysis, DNA MeSH
- Sequence Alignment MeSH
- Spores, Fungal cytology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Two strains of an unidentified perithecial ascomycete with a dactylaria-like anamorph and another morphologically similar strain of a dactylaria-like fungus were collected on decaying wood submerged in freshwater. To study their phylogenetic relationships we (i) combined sequence data from the nuclear small and large subunits ribosomal DNA (nc18S and nc28S) and the second largest subunit of RNA polymerase II (RPB2) for a multigene phylogenetic analysis and (ii) used sequences of the internal transcribed spacer region (ITS) of the rRNA operon for a species-level analysis. The new genus Pleurotheciella is described for two new species, Pla. rivularia and Pla. centenaria, with nonstromatic perithecia, unitunicate asci, persistent paraphyses and hyaline, septate ascospores and dactylaria-like anamorphs characterized by holoblastic, denticulate conidiogenesis, subhyaline conidiophores and hyaline, septate conidia. Based on morphological and molecular data, Pleurotheciella is closely related to the genera Pleurothecium and Sterigmatobotrys. A key to the three genera and the known species is provided. In the three-gene inferred phylogeny, these genera grouped as a sister clade to the Savoryellales within a robust clade of uncertain higher rank affiliation. Phylogenetic study of the 12 strains that represent Pleurothecium recurvatum revealed four that grouped apart from the core of the species. Two of these strains, which form a monophyletic well supported clade in both phylogenies and share similar morphological characteristics, are described as a new species, Pleurothecium semifecundum.
- MeSH
- Ascomycota classification cytology genetics isolation & purification MeSH
- DNA, Fungal chemistry genetics MeSH
- Wood microbiology MeSH
- Fungal Proteins genetics MeSH
- Phylogeny * MeSH
- DNA, Ribosomal Spacer chemistry genetics MeSH
- Molecular Sequence Data MeSH
- Multilocus Sequence Typing MeSH
- Mycological Typing Techniques MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA Polymerase II genetics MeSH
- Base Sequence MeSH
- Sequence Analysis, DNA MeSH
- Fresh Water MeSH
- Spores, Fungal classification cytology genetics isolation & purification MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: The aim of this basic study was to investigate by scanning electron microscopy the effects of cytoskeleton inhibitors on conidiogenesis and capsule in the yeast Fellomyces fuzhouensis CBS 8243, related to Cryptococcus neoformans. METHODS: Cells were treated by methyl benzimidazole-2-ylcarbamate (BCM) and latrunculin A (LAT) in yeast extract peptone dextrose medium and examined by scanning electron microscopy. RESULTS: During conidiogenesis, mother cells covered by capsule formed hypha-like stalks and at the hyphal tip yeast-like conidium developed. LAT blocked both stages of conidiogenesis. Inhibited mother cells and conidia became spherical and their capsule disappeared. BCM did not block formation of conidia that were neckless, or affect capsule. Combined application of LAT and BCM blocked both stages of conidiogenesis, cells became spherical and their capsule disappeared. CONCLUSION: Yeast cells with disrupted actin cytoskeleton do not reproduce by conidiogenesis and do not retain inherited cell shape and capsule.
- MeSH
- Basidiomycota drug effects ultrastructure MeSH
- Bridged Bicyclo Compounds, Heterocyclic pharmacology MeSH
- Cytoskeleton drug effects ultrastructure MeSH
- Microscopy, Electron, Scanning methods MeSH
- Spores, Fungal drug effects ultrastructure MeSH
- Thiazolidines pharmacology MeSH
- Cell Shape drug effects MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
