Studies in Mycology No. 64

This volume presents a re-evaluation of phylogenetic relationships within the class Dothideomycetes, which is by far the largest and arguably most phylogenetically diverse class within the largest fungal phylum, Ascomycota. This issue contains 10 papers, combining the efforts and data from a diverse group of researchers. Such a well-sampled phylogeny is especially important for comprehending how fungi have evolved as they shift ecological habitats and adapt to new environments and nutritional modes. A comprehensive phylogeny, derived from five genes, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41 families in Dothideomycetes, is presented. If required to delineate taxa in specific families, additional genes (ITS, ?-tubulin) were sequenced. All currently accepted orders in the class are represented for the first time in addition to numerous previously unplaced lineages. In total 78 novelties are introduced, including six families, 11 genera, 27 species, 33 new combinations and one new name. An ancestral reconstruction of basic nutritional modes supports numerous transitions from saprobic life histories to plant associated and lichenised modes and a transition from terrestrial to aquatic habitats are confirmed. Finally, a genomic comparison of six dothideomycete genomes with other fungi finds a high level of unique protein associated with the class, supporting its delineation as a separate taxon.