Phylogeny of the anamorphic genus Chrysosporium and related taxa based on rDNA internal transcribed spacer sequences.

Abstract

Phylogenetic relationships of 57 species of Chrysosporium and related species belonging to Onygenales and Sordariales were studied by analysing the nucleotide sequences of the 5·8S rRNA gene and their flanking ITS1 and ITS2 regions. Chrysosporium is a polyphyletic taxon with affiliations to at least two orders of the Ascomycota. The phylogenetic trees obtained in this study divided the genus into nine highly supported monophyletic groups (clades I-IX). However, relationships among these groups were not resolved. These groups were consistent for both methods of comparison (neighbor-joining and parsimony) and clearly correlated with groupings based on classical morphological criteria, enzymatic capabilities and teleomorph morphology. The genus Chrysosporium should be restricted to anamorphs of Onygenales, while Geomyces should be restricted to anamorphs of Myxotrichaceae and Myceliophthora to anamorphs of Sordariales. This study also demonstrates that several pairs of species are very similar, which suggests that they are synonymous, e.g. C. articulatum and A. reticulosporus; C. keratinophilum and A. keratinophilus and C. lucknowense and C. mephiticum.