Molecular and serological differentiation of Plum pox strains in three plum-growing areas situated in Transylvanian fruit central area, Romania

D. Pamfil, D. Briciu, A. Briciu

Abstract: Plum Pox virus (PPV) is the most destructive viral pathogen of stone species and is responsible for a serious loss of production particularly for susceptible varieties. This virus is very dangerous because it reduces the quality and causes the premature fall of fruits. Therefore, PPV is considered one of the main factors that make the plum crop to be considered no longer profitable. The virus has gradually spread to most of Europe, around the Mediterranean basin and Middle East. Also, the virus was found in India and America (Chile, USA and Canada). In Romania, Plum pox virus is prevalent in virtually all areas of the plum crop, causing a significant loss of production particularly for some susceptible varieties. Ninety PPV isolates were collected from three fruit-growing centers from Transylvania. Molecular strain differentiation was done by RT-PCR analyzed three genomic regions of the virus (Cter)CP, (Cter)Nib-(Nter)CP and CI. With RFLP analysis we could distinguish the two major strains, D and M based on Rsa I polymorphism located in (Cter)CP. Serological analysis were performed using DASI-ELISA technique with PPV-D and PPV-M specific monoclonal antibodies. All PPV isolates typed as PPV-M by molecular and serological analysis in the (C- ter)CP genomic region proved to be recombinants (PPV-REC) between D and M when we make the analysis in (Cter) Nib – (Nter)CP region. Differentiation and distribution of isolates shows that in Reghin and Cluj regions PPV-D are the predominant strain, with the highest percentage in Reghin (80%) and in Bistrita mixed infections prevail (60%). PPV-Rec strain has the highest percentage in Bistrita and Reghin regions with the same percentage of 13%.

Keywords: diagnosis; differentiation; PPV; RFLP; RT-PCR; virus strains

Date published: 2019-06-10