|Levy, Lorraine - USDA-APHIS|
|Mink, Gaylord - WASH ST UNIV|
|Howell, W - WASH ST UNIV|
Submitted to: Acta Horticulture Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 1997
Publication Date: N/A
Technical Abstract: A repository of graft-transmissible tree fruit virus disorders has been established in containment at the Foreign Disease-Weed Science Research Unit in Frederick, MD, for the purpose of developing diagnostic detection methodology for each disorder. Exotic (foreign) isolates were obtained from France, Hungary, and New Zealand. Endemic isolates were obtained from Prosser and Wenatchee, WA and Glenn Dale, MD. Eleven different woody indicators were inoculated with one chip graft and one bud graft for each isolate, 3 plants per treatment set. Inoculation buds were allowed to grow out and symptoms to develop in the indicator hosts. Several weeks after grafting, the indicator plants were cut back to within 4 inches of the top graft to force flushing. Symptoms of some disorders appeared in more than one indicator and several disorders failed to develop in any indicator. Prunus tomentosa had more positive infections than any other indicator. Exotic disorders exhibiting descriptive and/or diagnostic symptoms in P. tomentosa include all forms of plum pox virus (PPV), apple chlorotic leaf spot/plum bark split (ACLS/PBS), apricot stone pitting (ASP), cherry raspleaf-Hungary (CHRL), cherry rusty mottle (CRM), European rusty mottle (ERM), myrobalan latent ringspot virus (MLRV), and plum mottle (PM). P. tomentosa is easy to grow and maintain, retains symptoms after repeated severe prunings, and is useful both as an indicator and stock culture.