Taxonomy and phylogeny of white-rot polypores: case studies in Hymenochaetales and Polyporales (Basidiomycota)

This thesis deals with taxonomy of certain white-rot polypores placed for the most part in the genera Antrodiella, Cinereomyces, Junghuhnia and Steccherinum. With DNA-based phylogenetic analyses and morphological studies I and my co-authors showed that concepts of those genera and species within them need a major revision. Species of Antrodiella belong to at least 13 different genera, within Polyporales and Hymenochaetales, five of them undescribed. Species diversity within all the abovementioned genera is higher than considered so far. Formally, I resurrected five unused species names in Antrodiella, and recorded two Antrodiella species new to Finland. Three new genera, Obba (typified by Ceriporiopsis rivulosa var. valdiviana), Sebipora (typified by S. aquosa, a new species from Indonesia), and Sidera (typified by Cinereomyces lenis) were described. The genus Cyanotrama (Hymenochaetales) was appended with two former Antrodiella species. In the strict sense, Antrodiella, Junghuhnia and Steccherinum are rather closely related genera within Polyporales. In DNA-based phylogenetic analyses they form a distinct clade together with several other genera, for which we coin the name Steccherinaceae. Steccherinaceae includes 15 existing genera and at least 15 undescribed genera. All the species so far recorded within Steccherinaceae have a poroid or hydnoid hymenophore, and it seems that for the most part hydnoid versus poroid fungi belong to separate, monophyletic genera. There are exceptions: Antrodiella, Metuloidea and Steccherinum in the strict sense include both hymenophore types. Sidera (Hymenochaetales) is a similar case, in which I included both hydnoid and poroid fungi. Morphological and DNA-based results could be reconciled in defining genera and species in all studied groups with the exception of Steccherinum, where possible genus solutions include either microscopically widely different species within a genus (wide genus concept) or genera that can not be differentiated from each other (narrow genus concept). Dense taxon sampling including tropical material was essential for reaching robust phylogenies; on the contrary, addition of non-nrDNA sequence data did not affect the results almost at all.