|Levy, L - APHIS|
|Mink, G - WASHINGTON STATE UNIV|
|Howell, W - WASHINGTON STATE UNIV|
Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: June 15, 1998
Publication Date: N/A
Interpretive Summary: Many graft-transmissible agents are prevented from being moved from country to country by strict quarantine measures. Whenever stone fruit (Prunus) budwood is imported into the U. S. from any country where reports of graft-transmissible agents exist, the budwood must be carefully examined for any evidence of carrying disease causing agents which could become established in the U.S. This process can be extended up to several years and new methods of more rapid detection are needed. As a preliminary to such study, a repository of "foreign" agents has been established within quarantine facilities in Frederick by grafting buds or bark chips from infected budwood into a variety of woody indicator species, especially Prunus tomentosa, and allowing the symptoms of each disease to be expressed. A specific hybrid of P. tomentosa which was developed in Prosser, WA was found to be extremely versatile in its expression of different foreign and domestic pathogenic conditions. It is recommended that this hybrid along with the peach indicator GF 305, widely used in Europe, form the nucleus for identifying most graft-=transmissible agents in Prunus.
Technical Abstract: A repository of graft-transmissible tree fruit virus or virus-like disorders has been established in quarantine containment at the Foreign Disease-Weed Science Research Unit (FDWSRU) in Frederick, MD for the purpose of developing diagnostic detection methodology for each disorder. Isolates from France, Great Britain, Hungary, New Zealand, Turkey, Prosser, WA and Glenn Dale, MD, USA were incorporated into the repository. Budwood of each disorder was grafted into eleven different woody indicators. Most of the indicators under evaluation failed to exhibit any symptoms of any isolate, however, descriptive and/or diagnostic symptoms developed in P. tomentosa (hybrid selection IR473 X IR474) for many disorders not found in the US, including all forms of plum pox (PP), apple chlorotic leaf spot/plum bark split (ACLS/PBS), apricot stone pitting (ASP), cherry Amasya disease (AV), cherry raspleaf-Hungary (CHRL), cherry rusty mottle - European (ERM), false cherry mottle leaf (FCML), Myrobalan latent ringspot (MLRS), and plum mottle leaf (PM). P. tomentosa also exhibited symptoms of ten virus diseases found in the US. P. tomentosa was shown to be useful both as a woody indicator and stock culture plant because it is easily grown and maintained under greenhouse conditions and retains symptoms after repeated severe prunings.