First report of Plum bark necrosis stem pitting-associated virus infecting flowering cherry in Japan.
During a recent survey (2015), 5 Japanese flowering cherry trees (Prunus serrulata) samples collected in Japan with diverse virus-like discolorations and spotting on their leaves but without obvious bark or stem symptoms were analysed by Illumina deep sequencing of purified double-stranded RNAs. For 3 samples collected in parks in Kyoto, 3 to 11 of the assembled contigs showed high nucleotide identity values with the sequences of French Plum bark necrosis stem pitting-associated virus (PBNSPaV) isolates from Prunus salicina. Graft inoculation experiments had already demonstrated that P. serrulata was a host of PBNSPaV, but this is thought to be the first report of PBNSPaV infection in this host or of PBNSPaV presence in Japan. As is almost always the case, the trees analysed were multiply infected with several other viruses, including Cherry virus A, Little cherry virus 2 and, for some of them, Little cherry virus 1 or Cherry necrotic rusty mottle virus, precluding any efforts to link the observed foliar symptoms with the presence of PBNSPaV.