Theses and Dissertations Collection

Wine grape production has steadily increased since planting of grape vines began in the 1870s. Although wine grape production is a relatively young industry within Idaho, the state now has over 50 wineries and an annual economic impact of nearly $170 million. Due to the significance of the industry to Idaho, it is important to understand the presence and diversity of viruses associated with diseases of grapevines that may put the industry at risk. The most common of these diseases is the grapevine leafroll disease caused by a complex of Grapevine leafroll-associated viruses (GLRaV), of which the most prominent is GLRaV-3. In Idaho, a novel genetic variant of GLRaV-3 was identified in separate vineyards infecting different wine grape cultivars. Recently, a new virus was also identified in Idaho vineyards for the first time, Grapevine red blotch virus (GRBV), already widely present in California, Washington, and New York. It is important to understand the characteristics of these viruses, the effects on vine health, and to develop methods for detection. Here a preliminary study of the GLRaV-3 and GRBV genetic diversity in Idaho is presented. The development of detection methods for screening of planted and nursery stock vines can have a substantial impact on the wine industry to ensure planting of virus-free stock and/or economical and agronomic reasons to remove infected commercial plantings.