Accurate identification of plum pox potyvirus and its differentiation from Asian prunus latent potyvirus in Prunus germplasm1

Abstract

We have determined the accuracy of plum pox potyvirus (PPV) identification in reverse transcription‐polymerase chain reaction (RT‐PCR) assays using DNA primers for the 3’non‐coding region of PPV as compared with primers for a segment of PPV coat protein. Only primers for the 3’non‐coding region were specific for PPV identification. Primers for PPV coat protein reacted with other known potyviruses such as potato Y potyvirus and papaya ringspot potyvirus. The 3’non‐coding region sequence of PPV has great value in the specific differentiation of PPV from other potyviruses. PPV is the only potyvirus so far known to infect Prunus spp. We have now identified a latent virus, which we have named Asian prunus latent potyvirus (APLV), that infects germplasm of peach and Prunus mume. PPV can be differentiated from APLV by RT‐PCR using DNA primers specific for the 3’non‐coding region of the PPV genome. APLV, however, reacts positively with PPV coat‐protein primers in RT‐PCR assay, PPV cDNA probe of cloned PPV cDNA containing the coat protein gene in molecular hybridization assays, and PPV antiserum in serological assays.