Phylogenetic relationships among species of the genus Bensingtonia and related taxa based on the small subunit ribosomal DNA sequences.

Abstract

Small subunit ribosomal RNA gene sequences were determined in nine species of the ballistoconidium-forming yeast genus Bensingtonia. The phylogenetic trees were constructed for the species of the genus Bensingtonia and related taxa containing Sporobolomyces and Bullera species by neighbor joining, maximum parsimony and maximum likelihood methods. The phylogenetic trees showed that the basidiomycetous yeasts were divided into two main clusters, which were correlated well with the presence or absence of xylose in the cells. In the xylose-lacking basidiomycetous yeasts, seven species out of nine of the genus Bensingtonia constituted a distinct cluster. Bensingtonia ciliata, the type species of the genus, was included in this cluster. The remaining two species, B. intermedia and B. yamatoana, were located in the cluster which contained Rhodosporidium toruloides, Sporidiobolus johnsonii, Sporobolomyces roseus and Leucosporidium scottii. Erythrobasidium hasegawianum was distinctly located in the xylose-lacking basidiomycetous cluster. The molecular phylogeny showed clearly that the genus Bensingtonia was not monophyletic.