Molecular phylogeny of Trametes and related genera, and description of a new genus Leiotrametes.

A phylogenetic analysis of Trametes and related taxa is proposed, based on a wide sampling of temperate and tropical species. Concatenate sequences of ribosomal DNA (ITS1-5.8S-ITS2) and RPB2 gene from mycelia cultures were analyzed by Maximum Likelihood and Bayesian methods, whilst morphological features were documented from the corresponding herbarium vouchers. Congruent results were obtained from analyses of ribosomal LSU sequences downloaded from Genbank. The Bayesian analysis of ITS + RPB2 sequences gave the best resolution for the phylogenetic reconstructions and revealed the existence of three main lineages in the Trametes-clade: 1) a monospecific lineage represented by Artolenzites elegans 2) a lineage including the genus Pycnoporus in its traditional sense and several species usually classified in the genus Trametes ( T. cingulata, T. lactinea, T. ljubarskyi, T. menziesii) & 3) a lineage corresponding to the core genus Trametes, including type species of Trametes, Coriolopsis and Lenzites. The presence of a pseudostipe, aspect and structure of the abhymenial surface, colour change with 5% aqueous solutions of potassium hydroxide and topography of pigments on skeletal hyphae gave relevant morphological support to these clades. When the structure of the hymenial surface, presence of a black line below the tomentum and color of context (except for genus Pycnoporus) usually used in traditional polypore-classifications did not reveal any phylogenetic significance. A partial systematic arrangement of the Trametes clade is proposed, with the introduction of a new genus: Leiotrametes Welti & Courtec. gen. nov.. Two new combinations: Leiotrametes lactinea (Berk.) Welti & Courtec. comb. nov. and L. menziesii (Berk.) Welti & Courtec. comb. nov. are proposed. [ABSTRACT FROM AUTHOR]