Two novel saprobic Distoseptispora species from southern China (Distoseptisporales, Distoseptisporaceae)

Distoseptispora comprises ecologically significant species that are predominantly saprobic, inhabiting freshwater and terrestrial ecosystems, where they contribute to nutrient cycling and organic matter decomposition. Recent taxonomic studies have revealed several new Distoseptispora species, highlighting its high diversity. In this study, we describe two new species, Distoseptispora guanxiensis and D. longiconidiophora , isolated from decaying wood in southern China, thereby further expanding the known species richness of the genus. Based on multi-locus phylogenetic analyses integrated with the internal transcribed spacer (ITS), the large ribosomal subunit of the nuclear ribosomal DNA (LSU), the RNA polymerase II second largest subunit ( rpb 2), and the translation elongation factor 1-alpha ( tef 1-α), our isolates of D. guanxiensis formed a well-supported lineage sister to D. rayongensis , while D. longiconidiophora formed a basal position relative to the clade comprising D. cangshanensis , D. cylindricospora , D. hongheensis and D. pulchra . Morphological characteristics of the new species are compared with their phylogenetically close relatives, and detailed descriptions, illustrations, and phylogenetic data are provided. This study highlights the high diversity and distribution of Distoseptispora species, and emphasizes the importance of integrating morphological and molecular data for accurate species identification.