Identification and characterization of a novel Robigovirus infecting wild cherry trees in Tunisia

Wild rosaceous species may act as reservoirs for viruses infecting cultivated stone fruits. In this study, we surveyed wild cherry (Prunus avium) populations in forested areas of Tunisia in spring 2024. High-throughput sequencing (HTS) of pooled leaf samples revealed viral genomic fragments related to members of the genus Robigovirus. Here, we report the identification, complete genome sequencing, and preliminary prevalence assessment of a novel RNA virus from wild cherry, tentatively named wild cherry-associated virus (WCaV). The 8,254-nt genome comprises five canonical open reading frames (ORFs) exhibiting the typical organization of Robigovirus. These ORFs encode an RNA-dependent RNA polymerase (228.2 kDa), three triple gene block proteins (24.6, 12.4, and 7.2 kDa, respectively), a coat protein (28.8 kDa), and an overlapping hypothetical protein (ORF5a; 14.5 kDa). Phylogenetic inference, single nucleotide polymorphism (SNP) mapping, and recombination analyses indicate that WCaV constitutes a genetically distinct lineage within the genus. Field surveys showed limited local prevalence, consistent with a single-strain infection. Overall, this work broadens the known diversity of Robigovirus and provides the first molecular evidence of a novel Robigovirus infecting wild P. avium in Tunisia.