Submitted to: World Wide Web Aphis www.aphis.usda.gov
Publication Type: Other
Publication Acceptance Date: 6/21/2013
Publication Date: N/A
Interpretive Summary: Grapevine yellows, a seriously damaging disease of cultivated grapevine (Vitis vinifera L.), is caused by a very small bacterium called phytoplasma. In Australia, a phytoplasma (‘Candidatus Phytoplasma australiense’) causes a disease known as Australian grapevine yellows, which is responsible for heavy damage in Australian vineyards. This phytoplasma is termed exotic, because it has not been found in the U.S. The Animal and Plant Health Inspection Service (APHIS) as part of its Pest Detection program has initiated a program (Cooperative Agricultural Pest Survey, CAPS) to detect any possible introduction of this phytoplasma into U.S. vineyards. “The Pest Detection program supports APHIS’ goal of safeguarding U.S. agricultural and environmental resources by ensuring that new introductions of harmful plant pests and diseases are detected as soon as possible, before they have a chance to cause significant damage.”-APHIS The ARS Molecular Plant Pathology laboratory is assisting APHIS through research aimed at learning the precise identity of any phytoplasma that may be detected in U.S. vineyards during the surveillance program. The “Procedure for collecting and packaging grapevine samples” provides a protocol to help assure that grapevine samples are furnished in optimal condition, so that the phytoplasma, if present, will be detected and correctly identified. “The CAPS program conducts science-based national and state surveys targeted at specific exotic plant pests, diseases, and weeds identified as threats to U.S. agriculture and/or the environment.”-APHIS The procedure described in this online post will be used by national and state scientists, as part of the APHIS CAPS Program, and will also be of interest to scientists, researchers, diagnostics companies, and quarantine agencies studying the causes and spread of grapevine yellows diseases.
Technical Abstract: Grapevine yellows (GY) is a term that is used to refer to any of several diseases of grapevine (Vitis vinifera) that are caused by phytoplasmas. Around the globe, diverse ‘Candidatus Phytoplasma’ species cause indistinguishable disease symptoms in V. vinifera and are spread by different species of insect vectors. These features make it important so that any new introduction of an exotic grapevine yellows phytoplasma into the U.S. is detected as soon as possible. The Australian grapevine yellows disease caused by ‘Candidatus Phytoplasma australiense’ has not been reported in North America and is of high quarantine concern. This communication explains procedures for assuring that plant tissues are sampled and packaged optimally for shipment to laboratories conducting surveillance for exotic pathogens in U.S. vineyards. The procedures should aid early detection and identification of a phytoplasma, if present.