Phylogenetic analysis of the ballistoconidium-forming yeast genus Sporobolomyces based on 18S rDNA sequences

The 18S rDNA nucleotide sequences of 25 Sporobolomyces species and five Spo ridiobolus species were determined. Those of Sporobolomyces dimmenae JCM 87 62(T), Sporobolomyces ruber JCM 6884(T), Sporobolomyces sasicola JCM 5979(T ) and Sporobolomyces taupoensis JCM 8770(T) showed the presence of intron-l ike regions with lengths of 1586, 324 322 and 293 nucleotides, respectively , which were presumed to be group I introns. A total of 63 18S rDNA nucleot ide sequences was analysed, including 33 published reference sequences. Spo robolomyces species and the other basidiomycetes species were distributed t hroughout the phylogenetic tree. The resulting phylogeny indicated that Spo robolomyces is polyphyletic. Sporobolomyces species were mainly divided int o four groups within the Urediniomycetes. The groups are designated as the Sporidiales, Agaricostilbum/Bensingtonia, Erythrobasidium and subbrunneus c lusters. The last group, comprising four species, Sporobolomyces coprosmico la, Sporobolomyces dimmenae, Sporobolomyces linderae and Sporobolomyces sub brunneus, forms a new and distinct cluster in the phylogenetic tree in this study.