The phylogenetic relationships of species of the genus Dekkera van der Walt based on the partial sequences of 18S and 26S ribosomal RNAs (Saccharomycetaceae).

Eight strains of species of the teleomorphic genus Dekkera (and anamorphic genus Brettanomyces) were examined for their partial base sequences of 18S and 26S rRNAs. In the 26S rRNA partial base sequencings in positions 493-622 (130 bases) of 26S rRNA, D. bruxellensis (type species) (and B. bruxellensis, type species) and D. anomala (and B. anomalus) were related phylogenetically (percent similarities, 73-82). The percent similarity of D. naardenensis and D. custersiana were very low (48-56 and 48-53, respectively). In the 26S rRNA partial base sequencings in positions 1611-1835 (225 bases) of 26S rRNA, D. bruxellensis (and B. bruxellensis) and D. anomala (and B. anomalus) were related phylogenetically (base differences, 8-6). The base differences of D. naardenensis and D. custersiana were 46-38 and 38-27, respectively. In the 18S rRNA partial base sequencings in positions 1451-1618 (168 bases) of 18S rRNA, D. bruxellensis (and B. bruxellensis) and D. anomala (and B. anomalus) were closely related phylogenetically (base difference, one). The base differences of D. naardenensis were three with the above-mentioned two species. In contrast, D. custersiana was distant phylogenetically (base differences, 10-9). The sequence data obtained were discussed taxonomically, especially on setting up a new teleomorphic genus for D. custersiana.