A project is proposed to elucidate the evolution of secondary metabolism in the genus Buellia (lichenized
Ascomycotina). The genus is especially diverse with respect to secondary metabolism and therefore serves as an
ideal model group. Sequence information of the nuclear small subunit ribosomal DNA (ITS regions) and of the b -
tubulin gene from the mycobiont, will be used to establish a thorough phylogenetic hypothesis of Buellia and to
find the phylogenetic position of the genus in the larger context of the Physciaceae. This hypothesis will be used to
investigate gain or loss of biochemical pathways, which lead to the individual final chemical products in the
species. In parallel to the phylogenetic studies and in order to obtain a comprehensive inventory of secondary
metabolites, different methods will be used for the characterization of compounds, e.g. high pressure liquid
chromatography and mass spectrometry. Because other characters, e.g. thallus growth form, ascoma development
and ascospore structure also vary within the genus Buellia - and to a higher extend in the Physciaceae - the
phylogenetic concepts can be tested with a diversity of non-molecular characters. This project on the evolution of
biochemical pathways using nucleic acids sequence data is an pilot study in lichenology.