Phylogeny of the Sporidiobolales. Molecular phylogeny based on a concatenated alignment of the ITS region (ITS1, 5.8S and ITS2) and the D1/D2 domain of the LSU rRNA. Mating types (MAT A1 and MAT A2), asexual and self-fertile strains are designated as A1, A2, As and Sf, respectively. Circles before each strain depict the type of PR gene: yellow, STE3.A1; blue, STE3.A2; white, not detected; half-coloured circles, simultaneous detection of STE3.A1 and STE3.A2. For each species, the type strain is highlighted in boldface. A, B and C are three statistically well-supported clades (see text for details). Abbreviations of generic names: Rhodosporidium (R.), Rhodotorula (Rh.), Sporidiobolus (S.) and Sporobolomyces (Sp.). Asterisks indicate instances where the original mating type designation was altered to match the molecular identity of the strains (see Additional File 1). Species not yet formally described are indicated by inverted commas. The tree was rooted with sequences of Microbotryum lychnidis-dioicae and Leucosporidium scottii (see methods). Branch lengths are given in number of substitutions per site. Bootstrap values (>50%) from 1000 replicates are shown.