Description of the First Four Species of the Genus Pseudogymnoascus From Antarctica.

Pablo Villanueva,Anaí Díaz,Carlos Gil-Durán,Federico Laich,Eduardo Álvarez,Renato Chávez,Inmaculada Vaca,Marlene Henríquez,Vicente Oliva,Ghislaine Vásquez

doi:10.3389/fmicb.2021.713189

Abstract

The genus Pseudogymnoascus represents a diverse group of fungi widely distributed in different cold regions on Earth. Our current knowledge of the species of Pseudogymnoascus is still very limited. Currently, there are only 15 accepted species of Pseudogymnoascus that have been isolated from different environments in the Northern Hemisphere. In contrast, species of Pseudogymnoascus from the Southern Hemisphere have not yet been described. In this work, we characterized four fungal strains obtained from Antarctic marine sponges. Based on multilocus phylogenetic analyses and morphological characterizations we determined that these strains are new species, for which the names Pseudogymnoascus antarcticus sp. nov., Pseudogymnoascus australis sp. nov., Pseudogymnoascus griseus sp. nov., and Pseudogymnoascus lanuginosus sp. nov. are proposed. Phylogenetic analyses indicate that the new species form distinct lineages separated from other species of Pseudogymnoascus with strong support. The new species do not form sexual structures and differ from the currently known species mainly in the shape and size of their conidia, the presence of chains of arthroconidia, and the appearance of their colonies. This is the first report of new species of Pseudogymnoascus not only from Antarctica but also from the Southern Hemisphere.

Highlights

The fungal genus Pseudogymnoascus (Pseudeurotiaceae, Thelebolales, Leotiomycetes) was erected by Raillo (1929) to accommodate P. roseus and P. vinaceus, two species producing ascomata that Raillo distinguished from Gymnoascus based on differences in peridial hyphae
The phylogenies indicated that all the new species of Pseudogymnoascus of Antarctic origin were placed in distinct branches, forming clades separated from other species, with strong bootstrap support (Figure 1)
The four new species P. antarcticus, P. australis, P. griseus, and P. lanuginosus described in this work represent the first four species of Pseudogymnoascus from Antarctica and the Southern Hemisphere

Summary

Introduction

The fungal genus Pseudogymnoascus (Pseudeurotiaceae, Thelebolales, Leotiomycetes) was erected by Raillo (1929) to accommodate P. roseus and P. vinaceus, two species producing ascomata that Raillo distinguished from Gymnoascus based on differences in peridial hyphae. The phylogeny of Geomyces, Pseudogymnoascus, and other close genera was reorganized, including the transference of three species from other genera to the genus Pseudogymnoascus: P. destructans (formerly G. destructans), P. pannorum (formerly G. pannorum), and P. carnis (formerly Sporotrichum carnis) (Minnis and Lindner, 2013). These phylogenetic studies suggested that caves and similar environments in North America harbor several undescribed species of Pseudogymnoascus (Lorch et al, 2013; Minnis and Lindner, 2013). In 2020, three additional species of Pseudogymnoascus, P. shaanxiensis, P. guizhouensis, and P. sinensis, were described These species were isolated from soils collected in different locations in China (Zhang et al, 2020). These are the last species of the genus described to date, totaling only 15 accepted species of Pseudogymnoascus since 1929

Methods

Results

Conclusion