Taxonomy and molecular phylogeny of Trametopsis (Polyporales, Basidiomycota) with descriptions of two new species

Abstract

Trametopsis is a worldwide genus belonging to Irpicaceae in the phlebioid clade, which can cause a white decay of wood. Previously, only three species were ascribed to the genus. In this study, we performed a morphological and phylogenetic study of Trametopsis. Molecular phylogenetic analyses of multiple loci included the internal transcribed spacer (ITS) regions, the large subunit nuclear ribosomal RNA gene (nLSU), the largest subunit of RNA polymerase II (RPB1), the second largest subunit of RNA polymerase II (RPB2) and the translation elongation factor 1-α gene (TEF1). Phylogenetic trees were inferred from the combined datasets of ITS+nLSU sequences and ITS+nLSU+RPB1+RPB2+TEF1 sequences by using maximum parsimony, maximum likelihood and Bayesian inference analyses. Combined with molecular data, morphological characters and ecological traits, two new species of Trametopsis are discovered. Trametopsis abieticola is characterised by its pileate, solitary or imbricate basidiomata, buff to buff-yellow pileal surface when fresh, becoming pinkish buff to clay-buff when dry, cream to buff pore surface when fresh, becoming pinkish buff to greyish brown upon drying, round to angular and large pores (0.5–1 per mm), cylindrical basidiospores (5.8–7.2 × 1.9–2.6 μm), distributed in the high altitude of mountains and grows on Abies sp. Trametopsis tasmanica is characterised by its resupinate basidiomata, cream to pinkish-buff pore surface when fresh, becoming honey-yellow to snuff brown upon drying, cylindrical basidiospores (5.2–6.3 × 1.8–2.2 μm), and by growing on Eucalyptus sp. Detailed descriptions and illustrations of the two novel species are provided.