Ornamental Prunus species as new natural hosts of Plum pox virus and their importance in the spread of the virus in Hungary

Abstract

To determine the natural incidence of Plum pox virus (PPV) in ornamental Prunus species, surveys of 120 species/cultivars were conducted in Hungary between 2002 and 2007. Fifty-nine PPV-infected trees were detected by ELISA and/or PCR. Twenty-five were P. cerasifera cv. Nigra with dark red leaves, which accounts for a significant proportion of street-grown Prunus trees in Hungary. Molecular assays showed a prevalence of strain PPV-D (22) over PPV-M (2) and mixed infection of strains M and D (1). Infection was identified in: *Persica x davidiopersica cv. Atropurpurea, P. cerasifera, *P. cerasifera (Blue-fruited), *P. cerasifera (Light-pink-fruited), *P. cerasifera cv. Nigra, *P. cerasifera cv. Pendula, *P.cerasifera cv. Pissardii, *P. cerasifera cv. Woodii, P. glandulosa, *P. glandulosa cv. Alba Plena, *P. japonica, *Prunus x blireana, *Prunus x blireana cv. Moseri. On cultivars with dark-red leaves, symptoms could not be recognized even if the virus concentration was high. It can be assumed that in Hungary the latently infected red-leaved cultivars can play an important role in the wide distribution of PPV. Therefore it is a must to implement the certification scheme for propagating materials also considering that a number of Prunus species and cultivars (marked by an asterisk above) have been identified as previously unreported natural hosts of PPV in Hungary.