Multi-locus phylogenetic analyses reveal eight novel species of Distoseptispora from southern China

Abstract

Plant debris are habitat favoring the growth of various microbial species. Over the course of our mycological surveys in Jiangxi and Yunnan Provinces, China, eight new Distoseptispora species, viz. D. gasaensis , D. guanshanensis , D. jinghongensis , D. longnanensis , D. menghaiensis , D. menglunensis , D. nanchangensis , and D. yichunensis collected on dead branches of unidentified plants, were introduced by morphological and molecular phylogenetic analyses. Multi-locus (LSU, ITS, TEF1 , and RPB2 ) phylogenetic analyses were performed using maximum-likelihood and Bayesian inference to infer their taxonomic positions within Distoseptispora . Both molecular phylogenetic analyses and morphological characters supported them as eight independent taxa within Distoseptispora . This work improves our understanding of the diversity of Distoseptispora in southern China. IMPORTANCE Distoseptispora as a single genus in Distoseptisporaceae was introduced by morphological and phylogenetic analyses. Members of this genus occur mainly as asexual morphs, forming effuse, hairy colonies on decaying wood, plant stems, bamboo culms, and fallen leaves and shafts in terrestrial and freshwater habitats. In the present study, saprobic hyphomycetes from plant debris were investigated, and eight new Distoseptispora species were introduced based on morphology and phylogenetic analyses of LSU, ITS, TEF1 , and RPB2 sequence data. This study provides important data on the species diversity, ecological environment, and geographical area of Distoseptispora , greatly updates the classification of Distoseptispora , and improves our understanding of the taxonomy of Distoseptispora .

Diversity of Distoseptispora (Distoseptisporaceae) taxa on submerged decaying wood from the Red River in Yunnan, China

“…The morphological comparison between Distoseptispora xinpingensis and the closely related D. lignicola and D. menghaiensis shows that D. xinpingensis has longer conidiophores (105–149 µm vs. 84–124 µm) and conidia (107–139 µm vs. 60–108 µm), and with more conidial septate (8–12 vs. 5–9) than D. lignicola . Distoseptispora xinpingensis can be distinguished from D. menghaiensis by its longer conidiophores (105–149 µm vs. 45.7–82.9 µm) and conidia (107–139 µm vs. 35.7–48.6 µm), as well as conidial septation (8–12-euseptate vs. 4–8-distoseptate) ( Hu et al 2023 ). Given the morphological distinctions and evidence from phylogenetic analysis, we introduce Distoseptispora xinpingensis as a new species from the Red River Basin in Yunnan, China.…”

“…These species grow as saprophytes on a variety of decaying wood debris in tropical and subtropical freshwater and terrestrial habitats (Index Fungorum database; Hu et al 2023 ). 45 species have been reported on submerged bamboo stems and unknown wood debris in freshwater habitats, and 23 species have been reported on dead leaves, branches, and stems of various plants in terrestrial habitats, such as palms ( Hyde et al 2019 ), bamboo ( Monkai et al 2020 ), grasses ( Hyde et al 2023 ), and unknown broad-leaved trees ( Hu et al 2023 ), etc., and five species have been reported in both terrestrial and freshwater habitats ( Hyde et al 2016 ; Tibpromma et al 2018 ; Phookamsak et al 2019 ; Phukhamsakda et al 2020 ; Sun et al 2020 ; Shen et al 2021 ; Ma et al 2022 ; Zhang et al 2022 ). China and Thailand are the countries that contribute the most Distoseptispora species, with 50 species reported in China and 25 species reported in Thailand.…”

“…Important morphological characteristics are the color, shape, size, septation type (distoseptate/euseptate) and number of conidia, as well as the length of the conidiophores ( Zhang et al 2022 ). Phylogenetic studies of Distoseptispora are usually based on ITS , LSU , tef 1-α, and rpb 2 gene loci, and currently, all type species are well resolved on the phylogenetic tree ( Hu et al 2023 ; this study). Several previous studies have shown that new specimens of some species of Distoseptispora are significantly different in morphology from original descriptions, especially in the color and size of the conidia ( Yang et al 2018 ; Luo et al 2019 ; Shen et al 2021 ; Ma et al 2022 ).…”

“…BLAST searches using the BLASTn algorithm were performed to retrieve similar sequences from GenBank ( http://www.ncbi.nlm.nih.gov , accessed on 2 January 2024) and relevant publications ( Ma et al 2022 ; Zhang et al 2022 ; Hu et al 2023 ). The sequences were aligned using MAFFT online service: multiple alignment program MAFFT v.7 ( Kuraku et al 2013 ; Katoh et al 2019 ; http://mafft.cbrc.jp/alignment/server/index.html , accessed on 2 January 2024), and sequence trimming was performed with trimAl v1.2 with default parameters ( http://trimal.cgenomics.org for specific operation steps; Capella-Gutiérrez et al 2009 ).…”

“… Distoseptispora is a well-studied phylogenetic genus introduced by Su et al (2016) to accommodate some Sporidesmium taxa with unbranched, olive green, cylindrical conidiophores, monoblastic, integrated, determinate, terminal, cylindrical conidiogenous cells, and acrogenous, distoseptate, cylindrical, smooth, darker conidia with slightly paler (but not hyaline), rounded apices of indeterminate length ( Su et al 2016 ; Yang et al 2018 , 2021 ; Zhang et al 2022 ). Based on morphological and phylogenetic analyses, 73 species have been accepted in Distoseptispora in recent years ( http://www.indexfungorum.org/Names/Names.asp ; accessed on 2 January 2024; Hu et al 2023 ). These include the type species D. fluminicola McKenzie, Hong Y. Su, Z.L.…”