Cortinarius phylogeny and possible taxonomic implications of ITS rDNA sequences

Internal transcribed spacer (ITS) nuclear ribosomal DNA (rDNA) sequences of 2'7 species of Cortinarius representing the subgenera Cortinarius, Dermocy be, Leprocybe, Myxacium, Phlegmacium, Sericeocybe, and Telamonia were studi ed and compared with ITS rDNA of Rozites caperatus and three outgroup taxa: Gymnopilus sapineus, Hypholoma capnoides, and Tricholoma equestre. With tw o different gap treatments, the sequence data were used to reconstruct the phylogeny of Cortinarius using maximum parsimony (PAUP). Alternative outlin es of the subgenera compiled from literature were used to create phylogenet ic constraints which were subjected to parsimony analysis using the ITS dat a. Unconstrained and constrained parsimony trees were compared using a maxi mum likelihood method (DNAML/PHYLIP). In the ITS based phylogenies Cortinar ius s. l. was consistently divided into two lineages, one centered around t he members of the subgenus Telamonia, the other comprising the majority of ingroup taxa including Rozites. Because additional data are needed before n omenclatorial changes are considered, we present an outline of what may be regarded as two separate genera, Cortinarius s. s. and "Telamonia." The sta tus of Rozites will depend on similar future studies.