PHYLOGENETIC-RELATIONSHIPS AMONG SPECIES OF THE GENUS BENSINGTONIA AND RELATED TAXA BASED ON THE SMALL-SUBUNIT RIBOSOMAL DNA-SEQUENCES

Small subunit ribosomal RNA gene sequences were determined in nine spe cies of the ballistoconidium-forming yeast genus Bensingtonia. The phy logenetic trees were constructed for the species of the genus Bensingt onia and related taxa containing Sporobolomyces and Bullera species by neighbor-joining, maximum parsimony and maximum likelihood methods. T he phylogenetic trees showed that the basidiomycetous yeasts were divi ded into two main clusters, which were correlated well with the presen ce or absence of xylose in the cells. In the xylose-lacking basidiomyc etous yeasts, seven species out of nine of the genus Bensingtonia cons tituted 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 contai ned Rhodosporidium toruloides, Sporidiobolus johnsonii, Sporobolomyces roseus and Leucosporidium scottii. Erythrobasidium hasegawianum was d istinctly located in the xylose-lacking basidiomycetous cluster. The m olecular phylogeny showed clearly that the genus Bensingtonia was not monophyletic.