Characterization of a new mitovirus infecting the phytopathogenic fungus Microdochium albescens.

A novel mycovirus was identified infecting the phytopathogenic fungus Microdochium albescens. The characterized dsRNA segment, corresponding to the replicative intermediate of the mitovirus genome, is 2,562 base pairs (bp) in length, with an A+U content of 62.3%. A single open reading frame (ORF) was identified, encoding a putative RNA-dependent RNA polymerase (RdRp) of 706 amino acids. Phylogenetic analysis showed that this virus should be classified as a member of a new species in the genus Mitovirus, family Mitoviridae, for which we propose the name "Mitovirus gaucho". This is the first report of a mycovirus infecting the phytopathogenic fungus M. albescens, the causative agent of leaf scald on rice in Brazil.