Two novel species of Papiliotrema (Rhynchogastremataceae, Tremellales) isolated from flowers in northern Thailand

The genus Papiliotrema (Rhynchogastremataceae), which includes basidiomycetous yeast species, has a worldwide distribution. In this study, six Papiliotrema strains were isolated from flowers of Allamanda cathartica, Bidens pilosa, Cananga odorata, Oncidium sp., and Plumeria obtusa collected in Chiang Mai Province, northern Thailand, in 2024. An integrative taxonomic approach combining multilocus phylogenetic analyses using sequences of the internal transcribed spacer (ITS), the D 1 / D 2 domains of the nuclear ribosomal large subunit (D 1 / D 2), the largest subunit of RNA polymerase II (rpb 1), the second-largest subunit of RNA polymerase II (rpb 2), and translation elongation factor 1 - alpha (tef 1 - α) with detailed phenotypic characterization revealed that these strains represent two novel species, namely Papiliotrema anthoicola sp. nov.

(holotype, SDBR-CMU 883 T) and P. floralis sp. nov. (holotype, SDBR-CMU 888 T). Phylogenetic analysis clearly demonstrated that these taxa are distinct from other Papiliotrema species.

Full descriptions, illustrations, and a phylogenetic tree showing the positions of the two Papiliotrema species identified in this study are provided.