Biodiversity of lignicolous freshwater fungi from the Nanpan River Basin in Guizhou and Guangxi Provinces, China, with descriptions of fifteen species
Unknown authors
Abstract
The karst-dominated Nanpan River Basin (flowing through Yunnan, Guizhou and Guangxi Provinces, China) harbors unique aquatic ecosystems, however, the freshwater fungal diversity remains poorly studied. This study aims to investigate the taxonomic composition, diversity, and distribution patterns of lignicolous freshwater fungi using an integrative approach combining morphological observation and molecular phylogenetics. A total of 352 strains of lignicolous freshwater fungi were isolated from submerged decaying wood from the Nanpan River Basin in Guizhou and Guangxi Provinces, during 21–25 Nov 2024. Molecular identification via BLASTn analysis of ITS or LSU sequences revealed 189 species across 104 genera, 70 families, 27 orders, and six classes. Guizhou Province exhibited higher species richness, with 136 species identified from 213 strains, compared to 79 species from 139 strains in Guangxi Province. Community composition analysis revealed that only a few genera (32) and species (26) overlapped between the two provinces. Dictyocheirospora and Periconia were the dominant genera common to both provinces; Pseudohalonectria (6.1%), and Myrmecridium (5.2%) dominated in Guizhou, whereas Neokalmusia (7.9%) and Pseudoastrosphaeriella (5%) were the dominant genera in Guangxi. In addition, ten new species are introduced, namely: Apiospora submersa, Lolia guangxiensis, Neomyrmecridium submersum, Ophioceras lignicola, Pseudoteichospora aquatica, Tetraploa guizhouensis, T. nanpanjiangensis, T. verrucispora, Veronaea submersa, and Wongia guizhouensis based on characteristics and phylogenetic evidence. Wongia bandungensis is synonymized under W. suae based on phylogenetic analysis and morphological characteristics. In addition, five known species were collected and are described. These findings significantly expand the known diversity of lignicolous freshwater fungi in Southwest China, highlighting the basin as a hotspot for understudied freshwater fungal taxa and providing critical baseline data for the conservation and ecological study of these ecologically important organisms.