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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #431942
Research Project: Development of Applied Management Systems for Diseases of Perennial Crops with Emphasis on Vector-Borne Pathogens of Grapevine and Citrus

Location: Crop Diseases, Pests and Genetics Research

Title: Early detection of Grapevine leafroll-associated virus 3 in a table and raisin grape germplasm collection in Central California

Author
item Zhai, Ying
item Riaz, Summaira
item Peng, Hao

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2026
Publication Date: 6/15/2026
Citation: Zhai, Y., Riaz, S., Peng, H. 2026. Early detection of Grapevine leafroll-associated virus 3 in a table and raisin grape germplasm collection in Central California. Meeting Abstract. Presented at the 2026 American Society for Enology and Viticulture National Conference (ASEV), June 15-18, 2026 in Boise, Idaho.

Interpretive Summary:

Technical Abstract: Caused by grapevine leafroll-associated virus 3 (GLRaV-3), grapevine leafroll disease (GLRD) is one of the most devastating viral diseases in most grape-growing regions worldwide. Unfortunately, due to a lack of understanding of the GLRaV-grapevine interaction, there are currently no applicable measures to cure GLRaV-3 infection. Most effective GLRD control strategies include planting certified virus-free grapevines and removing virus-infected vines through rogueing. Therefore, early detection of GLRaV-3 is critical for the timely removal of infected plants in the vineyard. Here, we evaluated the efficiency and accuracy of GLRaV-3 early detection by RT-PCR using a table and raisin grape germplasm collection in California’s Central Valley. The results were verified by late detection using enzyme-linked immunosorbent assay (ELISA). We found that the efficacy of RT-PCR-based GLRaV-3 early detection highly depends on the genotypes. Some GLRaV-3-infected germplasm could be detected by RT-PCR at an early stage, while other lines either generated inconsistent results between individual plants or exhibited only negative outcomes; however, they were almost all later confirmed to be GLRaV-3 positive by ELISA. The inconsistency is probably due to slower virus propagation and disease development in these lines. We also found that despite the lower GLRaV-3 early detection rate, all positive RT-PCR results are accurate and can be used to guide timely vine removal to prevent GLRaV-3 spread. Early detection of GLRaV-3 across various varieties and breeding lines provides valuable germplasm-dependent guidance for table and raisin grape growers and researchers in Central California, enabling them to initiate disease management as early as in April.