PHYLOGENETIC ANALYSIS OF AMBROSIAL SPECIES IN THE GENUS RAFFAELEA BASED ON 18S RDNA SEQUENCES

Cladistic analysis of characters derived from nuclear-encoded 18S rDNA sequences was used to infer the phylogenetic placement of ambrosial s pecies of the anamorph genus Raffaelea among perithecial ascomycetes. Of eight species in the genus investigated, seven resolve as a monophy letic lineage that forms a sister group to the sexual genus Ophiostoma . Raffaelea hennebertii, the single species excluded from this lineage , appears to be allied phylogenetically with species of Melanospora. T hese data are discussed in relation to the monophyly of Raffaelea and its relationship with other sexual and asexual fungal associates of wo od-boring Coleoptera. In addition, we report the presence of significa nt length variation in PCR-amplified 18S rDNA fragments for three of t he Raffaelea species studied.