Molecular phylogeny of Ustilago, Sporisorium, and related taxa based on combined analyses of rDNA sequences*

Combined analyses of ITS and LSU rDNA sequences were utilized to resolve the phylogenetic relationships of 98 members of the smut genera Lundquistia, Melanopsichium, Moesziomyces, Macalpinomyces, Sporisorium, and Ustilago (Basidiomycota: Ustilaginales). Minimum Evolution and Bayesian inference of phylogeny resolve three major groups of almost identical composition: Sporisorium, Ustilago, and a basal assemblage of both Ustilago and Sporisorium species. Macalpinomyces deserves generic rank regarding its type species M. eriachnes; all other Macalpinomyces species of our study clearly turn out to be part of Ustilago or Sporisorium. Lundquistia evidently belongs to Sporisorium. Moesziomyces, probably paraphyletic, stands basal to all other genera. Interestingly, Melanopsichium belongs to the Ustilago clade, being the only member of the ingroup not parasitizing on Poaceae. The patchy distribution of commonly used morphological characters along our phylograms points to their variability and dependence on the host's morphological traits instead of being valuable for resolving parasite phylogeny. The new combination: Sporisorium fascicularis comb. nov. (syn. Lundquistia fascicularis) is made.