Dioszegia zsoltii sp. nov., a new ballistoconidium-forming yeast species with two varieties

Abstract

As a result of conventional characterization of yeasts isolated from various plant leaves collected in Yunnan, China, six ballistoconidium-forming strains with orange-colored colonies were grouped together. Molecular phylogenetic analysis based on 18S rDNA sequencing showed that two representative strains of this group of yeasts, CH 2.068 and CH 2.497, were closely related to the species in the genus Dioszegia and had signature sequences typical of this genus. However, the six strains from Yunnan differed from the described Dioszegia species remarkably (14.5-17.7% nucleotide divergences) in the ITS (internal transcribed spacer) region sequences, which indicated that they represent a distinct species. Furthermore, among the six strains studied, the ITS region sequence comparison allowed the recognition of two subgroups represented by CH 2.068 and CH 2.497, which differ from each other in three bases in the ITS 2 region. DNA-DNA relatedness revealed that the two subgroups represent two varieties of a new species in the genus Dioszegia, for which Dioszegia zsoltii sp. nov. var. zsoltii and Dioszegia zsoltii var. yunnanensis var. nov. are proposed.