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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #428849
Research Project: Improved Pest and Disease Control for Enhanced Woody Perennial Tree Crop and Grapevine Production

Location: Crops Pathology and Genetics Research

Title: Incidence of grapevine (Vitis vinifera Cultivars) infecting viruses in winegrowing regions of North Carolina

Author
item HEAGY, KIMBERLY - North Carolina State University
item VOLK, EMMA - North Carolina State University
item TALTON, WIN - North Carolina State University
item RWAHNIH, MAHER AL - University Of California, Davis
item Sudarshana, Mysore
item ALMEYDA, CHRISTY - North Carolina State University
item MCDANIEL, ALEXA - North Carolina State University
item OLASUPO, IBRAHEEM - North Carolina State University
item HOFFMANN, MARK - North Carolina State University

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/2026
Publication Date: 4/2/2026
Citation: Heagy, K., Volk, E., Talton, W., Rwahnih, M., Sudarshana, M.R., Almeyda, C., Mcdaniel, A., Olasupo, I., Hoffmann, M. 2026. Incidence of grapevine (Vitis vinifera Cultivars) infecting viruses in winegrowing regions of North Carolina. Plant Health Progress. PHP-08-25-0209-RS. https://doi.org/10.1094/PHP-08-25-0209-RS.
DOI: https://doi.org/10.1094/PHP-08-25-0209-RS

Interpretive Summary: This manuscript describes the results of a survey for grapevine-infecting viruses in the wine grape production regions of North Carolina done during 2018-2020. The survey included collection and testing of petiole samples collected from 270 symptomatic grapevines from 14 vineyards for 8 most damaging viruses and a bacterial pathogen, Xylella fastidiosa, under the National Clean Plant Network. The results indicated that grapevine red blotch virus was the most frequently detected virus, present in a third (34.8%) of the grapevines tested, and thus warrants further epidemiological studies on spread and vector(s) prevalent in the region.

Technical Abstract: Field surveys of wine grapes (Vitis vinifera cvs.) were completed between 2018 and 2020 to understand the distribution and incidence of grapevine viruses in North Carolina (NC). In October and November of 2018-2020, 1,620 leaf petiole samples were collected from 270 symptomatic vines across 14 vineyards in North Carolina. The petiole samples were assessed for grapevine leafroll associated virus-2, -3, -4, -7 (GLRaV-2, -3, -4, -7), grapevine red blotch virus (GRBV), grapevine virus A (GVA), grapevine virus B (GVB), and tomato ring spot virus (TRSV). Samples were also tested for Xylella fastidiosa, a common bacterial pathogen in NC, and the causal agent of Pierce’s disease. Petiole samples were collected and immediately stored on ice overnight. Total nucleic acids were extracted from petiole samples and analyzed for the presence of viruses using reverse transcription polymerase chain reaction (RT-qPCR). Samples that crossed a CQ = 35 were considered positive. More than one third (34.8 %) of evaluated samples were positive for GRBV, while other viruses had lower incidence: GLRaV-3 at 8.1%, GLRaV-2 at 4.8%, and TRSV at 0.3%. For the bacterium Xylella fastidiosa, the total field incidence was 11.5%. The majority of GRBV infections were found in vineyards in the Yadkin Valley, with 46.7% of the positive samples sourced from this region alone. GLRaV-2 and GLRaV-3 were found just in a few vineyards, with a much lower incidence across the state. This study suggests GRBV as the main grapevine virus threat for NC and implies the need for further investigations on region specific vector presence and management methods.