Outline, Divergence Times, and Phylogenetic Analyses of Trechisporales (Agaricomycetes, Basidiomycota)

Abstract

Phylogenetic analyses inferred from the nuc rDNA ITS1-5.8S-ITS2 (ITS) data set and the combined 2-locus data set [5.8S + nuc 28S rDNA (nLSU)] of taxa of Trechisporales around the world show that <i>Sistotremastrum</i> family forms a monophyletic lineage within Trechisporales. Bayesian evolutionary and divergence time analyses on two data sets of 5.8S and nLSU sequences indicate an ancient divergence of <i>Sistotremastrum</i> family from Hydnodontaceae during the Triassic period (224.25 Mya). <i>Sistotremastrum</i> family is characterized by resupinate and thin basidiomata, smooth, verruculose, or odontoid-semiporoid hymenophore, a monomitic hyphal structure, and generative hyphae bearing clamp connections, the presence of cystidia and hyphidia in some species, thin-walled, smooth, inamyloid, and acyanophilous basidiospores. In addition, four new species, namely, <i>Trechispora dentata</i>, <i>Trechispora dimitiella</i>, <i>Trechispora fragilis</i>, and <i>Trechispora laevispora</i>, are described and illustrated. In addition, three new combinations, namely, <i>Brevicellicium daweishanense</i>, <i>Brevicellicium xanthum</i>, and <i>Sertulicium limonadense</i>, are also proposed.