Two taxonomic novelties in the Sordariomycetidae: Ceratolenta caudata gen. et sp. nov. and Platytrachelon abietis gen. et comb. nov. for Ceratosphaeria abietis

Abstract

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.

• Annulatascaceae
• Lentomitella
• life history
• Magnaporthaceae
• systematics
• three-gene phylogeny

Acknowledgments

This study was supported by the Project of the National Foundation of the Czech Republic ( GAP 506/12/0038) and as a long-term research development project of the Institute of Botany, Academy of Sciences No. RVO 67985939.

I thank Václav Štěpánek, who undertook the DNA sequencing of isolates of Ceratolenta and Platytrachelon and other newly sequenced fungi. I am grateful for the help of Jacques Fournier for his photographs of selected lignicolous ascomycetes, their ascomata, longitudinal sections and asci (Figs. 41–47). I wish to thank Walter Gams for carefully reading the manuscript and further suggestions.