Redefining Microascus, Scopulariopsis and allied genera

Abstract

The genera Microascus and Scopulariopsis comprise species commonly isolated from soil, decaying plant material and indoor environments. A few species are also recognised as opportunistic pathogens of insects and animals, including humans. In the past, the taxonomy of these fungi has been based on morphology only. With the aim to clarify the taxonomy and phylogeny of these fungi, we studied a large set of clinical and environmental isolates, including the available ex-type strains of numerous species, by means of morphological, physiological and molecular analyses. Species delineation was assessed under the Genealogical Phylogenetic Species Recognition (GCPSR) criterion using DNA sequence data of four loci (ITS region, and fragments of rDNA LSU, translation elongation factor 1-α and β-tubulin). The genera Microascus and Scopulariopsis were found to be separated in two distinct lineages. The genus Pithoascus is reinstated and the new genus Pseudoscopulariopsis is erected, typified by P. schumacheri. Seven new species of Microascus and one of Scopulariopsis are described, namely M. alveolaris, M. brunneosporus, M. campaniformis, M. expansus, M. intricatus, M. restrictus, M. verrucosus and Scopulariopsis cordiae. Microascus trigonosporus var. macrosporus is accepted as a species distinct from M. trigonosporus. Nine new combinations are introduced. Microascus cinereus, M. longirostris, P. schumacheri and S. flava are neotypified. A table summarising the morphological features of the species treated and identification keys for each genus are provided.