A new species of Gymnoascus with verruculose ascospores

Abstract

A new species, Gymnoascus verrucosus sp. nov., isolated from soil from Kalyan railway station, Maharashtra, India, is described and illustrated. The distinctive morphological features of this taxon are its verruculose ascospores (ornamentation visible only under SEM) and its deer antler-shaped short peridial appendages. The small peridial appendages originate from open mesh-like gymnothecial ascomata made up of thick-walled, smooth peridial hyphae. The characteristic morphology of the fungus is not formed in culture where it has very restricted growth and forms arthroconidia. Phylogenetic analysis of different rDNA gene sequences (ITS, LSU, and SSU) demonstrates its placement in Gymnoascaceae and reveal its phylogenetic relatedness to other species of Gymnoascus, especially G. petalosporus and G. boliviensis. The generic concept of Gymnoascus is consequently now broadened to include species with verruculose ascospores. A key to the accepted 19 species is also provided.