Viscospora peruviscosa, a new fungus in the Glomeraceae from a plantation of Theobroma cacao in Peru

Abstract

A new fungus, Viscospora peruviscosa, was detected in a Theobroma cacao plantation in the Huallaga province of San Martín State in Peru.The fungus was propagated in the greenhouse on Sorghum vulgare and Brachiaria brizantha. The fungus is similar to V. viscosa as it has two spore wall layers and also a viscose outer spore surface, but its spores are smaller ((30-) 44-56 (-65) × (25-) 44-54 μm) and the subtending hyphae generally are more pronounced funnel-shaped. Also, the walls of the spores and subtending hyphae are thinner than in V. viscosa. Phylogenetically, both species form two well separated sister clades in the genus Viscospora. Based on the partial nrDNA gene, the two species have 90-91% maximum identity (MI). So far, the fungus is only known from the cacao plantation in Huallaga. No environmental sequences in the public data bases suggest that the fungus has already been found elsewhere in the neotropics or worldwide. This is the second species in the genus Viscospora (Glomeraceae) described, hence Viscospora is no longer monospecific.