Molecular Characterization of the First Partitivirus from a Causal Agent of Salvia miltiorrhiza Dry Rot

Root rot as a result of is a common root disease caused by spp., which has become one of the main diseases affecting the production of . Currently, several hypovirulence-related mycoviruses have been identified in many phytopathogenic fungi, including spp., which show potential as biological controls. In this study, we report a new mycovirus, Fusarium oxysporum partitivirus 1 (FoPV1), isolated from strain FCR51, which is a causal agent of dry rot. The FoPV1 genome contains two double-stranded RNA segments (dsRNA1 and dsRNA2). The size of dsRNA1 is 1773 bp, and it encodes a putative RNA-dependent RNA polymerase (RdRp). The dsRNA2 is 1570 bp in length, encoding a putative capsid protein (CP). Multiple sequence alignments and phylogenetic analyses based on the amino acid sequences of the RdRp and the CP proteins indicated that FoPV1 appears to be a new member of the family that is related to members of the genus . Pathogenicity assay showed that FoPV1 confers hypervirulence to its host, . This is the first report of a partitivirus infecting and the first hypovirulence-related mycovirus from the causal agent of dry rot.