Molecular characterization of a novel fusarivirus infecting the plant-pathogenic fungus Nigrospora sphaerica.

Here, we describe a novel mycovirus, tentatively designated as "Nigrospora sphaerica fusarivirus 2" (NsFV2), which was isolated from the phytopathogenic fungus Nigrospora sphaerica strain HNXX-Ns20. NsFV2 has a single-stranded positive-sense RNA (+ ssRNA) genome of 6,156 nucleotides, excluding the poly(A) tail, and contains two putative open reading frames (ORFs). ORF1 encodes a large polypeptide of 1,509 amino acids (aa) containing a conserved RNA-dependent RNA polymerase (RdRp) domain and a viral helicase domain.