EN
Prune dwarf virus (PDV), a worldwide pathogen of stone fruit trees, has many isolates with different biological, serological and molecular properties. Monoclonal antibodies (MAbs) to the Prunus mahaleb isolate of PDV were used to investigate the serological variability of virus isolates, by TAS-ELISA (triple antibody sandwich enzyme-linked immunosorbent assay). The twenty-two PDV isolates from Germany (1), Italy (7), Poland (13) and the USA (1) were characterised against eight single MAbs. The virus showed high serological variability. Analysis of the MAbs reaction allowed for the identification of 13 serogroups.