First report of Prunus virus F infecting sweet cherry cultivars using high-throughput sequencing in Belgium.
Fruit trees, like sweet cherry (Prunus avium) are known to be infected by numerous plant viruses, predominantly as a consequence of their vegetative mode of propagation and extended cropping. Prunus virus F (PrVF) is a recently described member of the genus Fabavirus (Secoviridae) which has a poorly understood pathology. During a sweet cherry resistance screening greenhouse experiment (July 2018) against Little cherry virus 1 (LChV-1) and Little cherry virus 2, branches and leaves from 10 non symptomatic trees, representing propagation material from different cultivars grafted on Gisela 5 rootstocks, were collected and pooled as a single composite sample. Results of RNA sequence and phylogenetic analyses confirmed the presence of PrVF. The PrVF-infected trees also harboured other co-infecting Prunus viruses, such as LChV-1 and Cherry virus A which is considered a latent virus in Prunus. No pathological effect of PrVF could be discerned, as observed previously. These findings suggest a mixed infection of propagation material with PrVF and other viruses, as previously reported. This is thought to be the first report of PrVF infecting sweet cherry in Belgium.