A new lignicolous freshwater fungus, Helicosporium (Tubeufiaceae, Tubeufiales) from Guizhou Province, China

Abstract

A new lignicolous freshwater species of Helicosporium exhibiting an asexual morph was isolated from submerged woody substrates collected in Guizhou Province, China. Phylogenetic analyses based on a combined LSU, ITS, tef1-ɑ, and rpb2 sequences data revealed that the isolates form a well-supported, distinct lineage within Helicosporium. Morphological comparisons further showed a unique combination of characters, including macronematous, unbranched conidiophores, monoblastic or polyblastic conidiogenous cells with denticulate or bladder-like protrusions, and helicoid, aseptate, guttulate, hyaline conidia, distinguishing the fungus from currently known congeners. Based on the concordance of morphological and phylogenetic evidence, the collections are introduced herein as a new species of Helicosporium. Detailed descriptions, illustrations, notes, and phylogenetic analyses are provided to support its taxonomic placement.