Phylogeny of Megasporoporia s.lat. and related genera of Poyporaceae: New genera, new species and new combinations

Several resupinate poroid Polyporaceae with dextrinoid skeletal hyphae and cylindrical, thinwalled basidiospores have been placed in Dichomitus and Megasporoporia. With the inclusion of DNA sequences, mostly from Chinese material, in the phylogeny of the genera, new genera were recognized, i.e., Megasporoporiella and Megasporia. In the current study, Jorgewrightia and Mariorajchenbergia are described as new genera in the Polyporaceae based on phylogenetic analyses of four gene regions: nuc rDNA ITS1-5.8S-ITS (ITS) and partial Large Subunit (28S), Translation Elongation Factor 1-alpha (TEF1), and RNA polymerase II second largest subunit (RPB2), mostly from Brazilian material. These new genera currently accommodate species formerly placed in Cerioporus, Dichomitus, Megasporia, Megasporoporiella and Pachykytospora. Dichomitus, Jorgewrightia, Mariorajchenbergia, Megasporia and Megasporoporia have mostly resupinate pale-colored basidiomata, poroid hymenophore, usually dextrinoid branched skeletal hyphae, and cylindrical basidiospores. These genera are difficult to differentiate on morphology alone and analyses based on sequences from at least two regions (ITS and 28S), as well as information about geographical distribution, are needed to separate them. Megasporia variabilicolor and Megasporoporia neosetulosa are described as new species, and one neotype and 20 new combinations are proposed. Synoptic tables including characteristics for 27 species from the five genera is presented.