Two novel mitoviruses isolated from the filamentous fungus Gnomoniopsis sanguisorbae

In this study, we isolated two novel mitoviruses co-infecting the fungus Gnomoniopsis sanguisorbae, which were designated as “Gnomoniopsis sanguisorbae mitovirus L” (GsMV-L) and “Gnomoniopsis sanguisorbae mitovirus M” (GsMV-M). The complete genome lengths of GsMV-L and GsMV-M were determined to be 2,785 and 2,529 nucleotides, respectively, with a GC content of 44% and 35%, respectively. Both viruses possess a single open reading frame (ORF) that encodes an RNA-dependent RNA polymerase (RdRp) containing conserved catalytic motifs. BLASTp analysis revealed that the RdRps of GsMV-L and GsMV-M exhibited the highest amino acid sequence similarity to those of sunflower phomopsis-associated mitovirus 1 and Phomopsis viticola mitovirus 962_1, with 50.97% and 41.97% identity, respectively. Phylogenetic analysis based on RdRp sequences indicated that GsMV-L clustered with members of the genus Triamitovirus, while GsMV-M clustered with members of the genus Unuamitovirus, both of which are taxonomically classified within the family Mitoviridae.