Morphological and multi-gene phylogenetic analyses reveal Nigrellomyces gen. nov. and one new species in Pleurotheciaceae from China

By

Zhang, Wangming
Song, Xiao-Yu
Xie, Wanqing
Zhou, Xinzhong
Lu, Juan
Feng, Qinying

Type

Article

Date of Publication

2025-9-18

Original Publication

MycoKeys

Volume

122

Pages

277--292

Subjects

asexual morph , lignicolous freshwater fungi , Phylogeny , Sordariomycetes , taxonomy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers 2011-

Identifiers

DOI: https://doi.org/10.3897/mycokeys.122.164540

 

Abstract

Nigrellomyces is introduced herein as a new genus to accommodate a novel asexual ascomycete, Nigrellomyces aquaticus, isolated from submerged decaying wood in freshwater habitats in Guizhou Province, China. Phylogenetic analyses based on a combined dataset of ITS, LSU, SSU, and rpb2 sequence data robustly place Nigrellomyces within the family Pleurotheciaceae (Pleurotheciales, Savoryellomycetidae), with strong statistical support. The genus is currently known only from its asexual morph, which is characterized by macronematous, mononematous, erect, unbranched, septate conidiophores; polyblastic, integrated, terminal or intercalary, sympodial proliferations; denticulate conidiogenous cells with swollen apices; and acrogenous, subglobose to globose, ovoid to obovoid, or ellipsoidal, aseptate, guttulate conidia. Morphological comparisons reveal that Nigrellomyces displays a cordana-like conidiogenesis that is distinct from other genera in Pleurotheciaceae, which typically exhibit acrodictys-, helicoön-, monodictys-, or dactylaria-like asexual morphs. This study provides a comprehensive morphological description, illustrations, and comparative interpretation of the new taxon. An updated phylogenetic backbone tree of Pleurotheciaceae is also presented, improving resolution of intergeneric relationships within the family. The discovery of N. aquaticus not only expands the taxonomic framework of Pleurotheciaceae but also contributes to a deeper understanding of the species richness, ecological roles, and biogeographic distribution of lignicolous freshwater fungi in Southwest China, particularly in the underexplored region of Guizhou Province.