Evidence for non-transmission of plum pox virus by seed in infected plum and myrobalan

Four genotypes of plum (Prunus domestica L.) and myrobalan (Prunus cerasife ra EHRH.) naturally infected with plum pox virus (PPV) were analysed to inv estigate the possibility of seed transmission. All the trees were observed to develop typical symptoms of PPV infection on leaves. The fruit symptoms differed among genotypes. All the analysed trees were PPV-positive in DAS-E LISA and RT-PCR. RsaI-based restriction analysis of RT-PCR products reveale d the presence of PPV-M isolates (in cv. Bystricka and Vlaska) and PPV-D on es (in cv. Tuleu Gras and myrobalan). Using DAS-ELISA, PPV could not be det ected in any part of seed of all the genotypes. The PPV sequences amplified in RT-PCR were repeatedly identified in seed coat, but not in endosperm. T otally 104 seedlings from stratified seeds were periodically tested using D AS-ELISA for evaluating PPV infection during a-year period. Not even in a s ingle case was PPV antigen detected. On the basis of these results it can b e claimed that the identified PPV isolates are not seed-transmitted in Prun us genotypes tested.