The lichen-forming genus Porpidia (Porpidiaceae, Ascomycota) provides a model system for studying the evolutionary significance of sexual and asexual reproduction. The present study forms the basis for future detailed population genetic studies by analyzing the molecular phylogenetic relationships of the genus. Based on DNA-sequence variation in fragments of the nuclear large subunit ribosomal RNA gene (1.4 kb) and the ▀-tubulin gene (1 kb) the relationships within Porpidia and its relationships to closely related allies will be reconstructed. Included in the analysis are selected species of all described subgroups within the genus, representative species of potentially closely related genera within the Porpidiaceae and additional families, as well as relevant outgroup taxa. The results of both gene phylogenies will be discussed.

Key words: lichen-forming ascomycetes, molecular systematics, nuclear large subunit ribosomal RNA gene, Porpidia, Porpidiaceae, ▀-tubulin gene