Disentangling identity of species of the genus Taphrina parasitizing herbaceous Rosaceae, with proposal of Taphrina gei-montani sp. nov.

Five strains (CCY 058-007-001T, CCY 058-007-002, CCY 058-007-003, CCY 058-007-004 and CCY 058-007-005) of a novel parasitic yeast belonging to the genus Taphrina were isolated from leaf tissues of Geum montanum L. (Rosaceae), collected from the Vysoké Tatry Mountains, Slovakia. Genetic analyses revealed that these isolates differ by 15 unique substitutions in the ITS region and by six substitutions in the rns gene from all other species of the genus Taphrina analysed hitherto. The novel strains are also distinguished from all other species of the genus Taphrina by their morphology, biochemical properties and ecology. These strains represent a novel species, for which the name Taphrina gei-montani sp. nov. is proposed. The type strain is CCY 058-007-001T (=CBS 14159=BU001). The MycoBank number is MB815677. The present study also demonstrates that two distinct species of the genus Taphrina parasitize the herbaceous Rosaceae: Taphrina gei-montani sp. nov. on Geum montanum and Taphrina tormentillae on Potentilla species.

The reassignment of three 'lost' Taphrina species (Taphrina bullata, Taphrina insititiae and Taphrina rhizophora) supported by the divergence of nuclear and mitochondrial DNA.

The ascomycetous genus Taphrina Fries originally contained more than 90 phytopathogenic microscopic dimorphic ascomycetes causing specific infections in different vascular plants. Although species have mainly been identified historically according to their host and morphological and physiological traits, they can be studied and preserved in the form of yeasts arising from germinating ascospores. Due to low DNA sequence divergence and the lack of available strains, the number of accepted Taphrina species has currently been reduced to 28. The aim of this study is the description of three previously accepted species. Taphrina bullata (type strain CCY 58-4-1 = CBS 12783), Taphrina insititiae (type strain CCY 58-5-1 = CBS 12782) and Taphrina rhizophora (type strain CCY 58-6-1 = CBS 12781), which have been omitted from a recent key. The host range, the divergence of the 26S rRNA gene sequence, internal transcribed spacers (ITS) and the mitochondrial small ribosomal subunit (rns) sequence strongly support their reassignment as species.

Anther smut fungi on monocots.

Teliospores, hyphal septa, cellular interactions, and nucleotide sequences from the ITS and LSU region of the rRNA gene of specimens of Ustilago vaillantii s. lat. on Muscari and Scilla species were examined and compared with findings in other Ustilaginomycotina. The data show that U. vaillantii s. lat. specimens belong to the Urocystales and represent the sister group of the Urocystaceae, standing well apart from Vankya heufleri and V. ornithogali. Within the Urocystales, U. vaillantii s. lat. is unique in sporulating in the anthers of the host plants. Accordingly, the new genus Antherospora is proposed for the anther smuts on Hyacinthaceae. In addition, our data show that there is a stringent phylogenetic correlation between the specimens of Antherospora and their respective hosts. Thus, the specimens on Scilla spp. as well as those on Muscari spp. form highly supported monophyla. Furthermore, on Scilla a phylogenetic dichotomy exists between the specimens infecting Scilla bifolia and those infecting S. vindobonensis, with the specimens of the two host species showing a difference of 17bp in the ITS nucleotide sequences. Therefore, A. vindobonensis is described as a new species, and A. scillae and A. vaillantii are proposed as new combinations. Consequently, because of their sporulation in anthers and their parasitism on species of other genera of the Hyacinthaceae, Ustilago albucae, U. peglerae, U. tourneuxii, and U. urgineae are also ascribed to Antherospora as new combinations. Descriptions are given for all species.