A morphological and phylogenetic analysis of dematiaceous hyphomycete strains of Distoseptispora (Distoseptisporaceae, Distoseptisporales) and Kirschsteiniothelia (Kirschsteiniotheliaceae, Pleosporales) in southern China

Dematiaceous hyphomycetes are widely distributed throughout the world. They can live either saprophytically or parasitically and are commonly found growing on dead wood, in soil, and in aquatic environments. During an ongoing survey of saprophytic fungi in multiple southern provinces of China, two Distoseptispora -like and one Kirschsteiniothelia -like strains were isolated from decaying wood. Five barcodes (i.e., ITS, SSU, LSU, RPB2 , and TEF1 ) were amplified and sequenced. Of these markers, ITS, LSU, RPB2 , and TEF1 were selected for Distoseptispora , whereas ITS, LSU, and SSU were used for Kirschsteiniothelia . Based on maximum likelihood (ML) and Bayesian inference (BI) phylogenetic analyses, combined with morphological characteristics, three new species, Distoseptispora linchunlingensis , D. xinganensis , and Kirschsteiniothelia guiyangensis , are proposed. This study provides detailed illustrations, phylogenetic trees, and morphological descriptions to clarify the taxonomic status of the three new species, thereby improving our understanding of the diversity of dematiaceous hyphomycetes in Hainan, Guangxi, and Guizhou provinces, China.