Phylogenetic relationships of coprophilous Pleosporales (Dothideomycetes, Ascomycota), and the classification of some bitunicate taxa of unknown position

The purpose of this study was to investigate the natural relationships within the large bitunicate order Pleosporales, with special focus on the coprophilous families Delitschiaceae, Phaeotrichaceae and Sporormiaceae. Parsimony and Bayesian analyses were performed using nSSU, nLSU and mtSSU rDNA sequence data. We also investigated the placement of a number of taxa with uncertain position. Our results showed that Pleosporales, including Delitschiaceae, Sporormiaceae, Zopfiaceae and Testudinaceae, form a monophyletic group with strong support. Although Delitschiaceae has been considered a synonym of Sporormiaceae, the two families do not form one monophyletic group.Similarly, Zopfiaceae and Testudinaceae should be retained as separate families as they did not group together or with Phaeotrichaceae or Sporormiaceae. Zopfiaceae and Delitchiaceae did group together, but without significant support. Eremodothis angulata (currently in Testudinaceae) is closely related to Westerdykella in Sporormiaceae. Phaeotrichaceae and Venturiaceae formed a group with strong BS support on a branch outside Pleosporales, but an alternative topology including Phaeotrichaceae and Venturiaceae within Pleosporales could not be rejected. All taxa in the present study that were placed with uncertain position in Dothideomycetes/Chaetothyriomycetes in the current classification by Eriksson, grouped within the monophyletic Dothideomycetes.