Detection of plum pox virus in apricot seeds

Twelve different apricot selection trees from a germplasm collection naturally infected with plum pox virus (PPV) were chosen to investigate the role of seeds in the epidemiology of this dangerous pathogen. All the considered plants showed typical symptoms on leaves and fruits and were positive in enzyme-linked immunosorbent assay (ELISA). The virus was characterized by immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) followed by restriction fragment length polymorphism (RFLP) analysis with RsaI enzyme as a PPV-D isolate. The presence of PPV was checked on fully ripe seeds and seedlings. One half of the seed stock was analysed immediately by ELISA and IC-RT-PCR tests: the cotyledons containing also the embryo were separated from the teguments. The other half of the seed stock was germinated and maintained in an insect-proof screenhouse over a 2-year period. PPV was detected by ELISA only in the seed coat while by IC-RT-PCR also in cotyledons. Seedlings from infected seeds did not show any typical symptoms and were PPV-negative in serological and molecular assays. So far, the presence of PPV in seeds seems to play no role in its epidemiology.