Monitoring of Plum bark necrosis stem pitting-associated virus and molecular characterization of some isolates

Different Prunus species from Italy, Serbia, Turkey and Egypt were assayed by one-step RT-PCR and nested PCR for the presence of Plum bark necrosis stem pittingassociated virus (PBNSPaV). This virus had a fairly high incidence and was monitored throughout the year by IC-RT-PCR and ELISA. It was detected during all seasons by both techniques but most easily in spring in the new flushes of vegetation. Six PBNSPaV isolates were characterized by partial sequencing of three genomic regions, e.g. HSP70, coat protein and ORF4. High nucleotide similarity was found between all isolates from different geographic and host origins, suggesting either a relatively recent origin or the presence of unidentified constraint on variation.