Species delimitation in the Gloeocystidiellum porosum-clavuligerum complexinferred from compatibility studies and nuclear rDNA sequence data

Gloeocystidiellum porosum and Gloeocystidiellum clavuligerum are corticioid homobasidiomycetes with minor morphological differences and are generally regarded as a complex of closely related taxa. To infer phylogenetic relati onships and to aid in species delimitation, sequences of the internal trans cribed spacer 2 and the 5' end of the large subunit nuclear ribosomal DNA w ere obtained for 25 representatives of the species complex. Inter- and intr acompatibility tests between cultured representatives for all specimen grou ps were performed. Results of phylogenetic analyses based on DNA sequences were congruent with compatibility results. Gloeocystidiellum clavuligerum c onsists of two distinct taxa, and G. porosum includes at least two interste rile groups of uncertain taxonomic status.