Polyporaceae; cryptic species; Fomes fomentarius; molecular phylogeny; variability

The existence of two cryptic species within strains of the wood-decaying fungus Fomes fomentarius was revealed recently based on the internal transcribed spacer (ITS) sequence variability. In this study for the first time the sequences of another molecular markers, partial translation elongation factor 1-? (efa) region and partial 25S large subunit ribosomal RNA gene were obtained and used to evaluate genetic variability of F. fomentarius. Congruent phylogeny was observed for all three markers used confirming the presence of two cryptic species within F. fomentarius. Surprisingly, ITS sequence variability within F. fomentarius was significantly lower compared to the variability of efa sequences (0.023 versus 0.036 nucleotide substitutions per site) questioning the discriminatory power of ITS sequences for fungal species identification.