Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2010
Publication Date: June 1, 2010
Citation: Younkins, A.A., Stone, A.L., Sherman, D.J., Schneider, W.L., Scorza, R., Damsteegt, V.D. 2010. Analysis of visual symptomatology in peach and plum inoculated with U.S. PPV isolates. Phytopathology. 100:S209. Technical Abstract: Plum pox potyvirus (PPV) is an economically devastating potyvirus that affects Prunus species. Discovered in the United States, in 1999, the Pennsylvania PPV isolates were primarily found in peaches (Prunus persica). When several of these original Pennsylvania isolates were inoculated onto plums (Prunus domestica), the isolates either did not transmit or showed few symptoms. This suggests that Pennsylvania PPV isolates were more adapted to peach as a host. An expanded experiment was designed using a greater number of Pennsylvania and New York PPV isolates to identify a U.S. PPV isolate with severe visual symptoms in plums, and to determine if symptom severity correlated with PPV titer. Two plum varieties (Bluebyrd and Stanley) were inoculated with fourteen PPV isolates from New York and Pennsylvania by aphid (Myzus persicae) or by grafting. Visual symptom severity was determined using a standardized symptom rating system. PPV titers were measured using Enzyme Linked Immunosorbent Assay (ELISA) and Real-time one step reverse transcription-PCR (RT-PCR). In contrast to PPV infection in peach, there was little correlation between average symptom rating and average ELISA titer or average Real-time RT-PCR Ct value in plum. One PPV isolate had been maintained for 10 years in both hosts: peach and plum. When this isolate was inoculated onto plum from both peach and plum sources, differences in titer and symptoms showed a possible host adaptation between PPV maintained in plum or in peach tissue.