2008 Annual Report 1a.Objectives (from AD-416) Evaluate the affects of grapevine leafroll-associated viruses and Rupestris stem pitting associated virus on yield parameters and quality attributes of grapevines. 1b.Approach (from AD-416) Two rootstock-scion-virus interactions trial blocks will be established. The proposed trial will evaluate interaction of viruses with grapevines on different phylloxera-resistant rootstocks. Virus status of each plant will be confirmed by a combination of ELISA and RT-PCR tests for the GLRaVs and the RSPaV. Documents SCA with Washington State University. Formerely 5358-22000-028-07S (8/2007). 3.Progress Report Since grapevine leafroll-associated viruses (GLRaVs) and grapevine rupestris stem pitting-associated virus (GRSPaV) are wide spread in the Pacific Northwest, the goal of this project is to conduct research to address which rootstocks are most sensitive to graft incompatibility issues when the scions are infected with GRSPaV and/or GLRaVs, and to examine the effects of virus infections x scion x rootstocks on grapevine longevity and on grape yield components and quality. A research vineyard has been established in the Botany and Plant Pathology research farm at Oregon State University (OSU), Corvallis, OR. The Pommard clone of Pinot Noir was grafted on to four rootstocks, namely Couderc 3309, MGT 101-14, 420A and Riparia Gloire. Own-rooted grapevines of Pinot Noir will serve as controls. The trial consisted of a randomized split-block design with three replicates of each treatment for a total of 120 plots. Grapevines infected singly with GLRaV-1, -2, and -3 and GRSPaV were identified in different vineyards using molecular diagnostic assays. The following virus treatments were proposed in the spring of 2008 for chip bud grafting: GLRaV-1, GLRaV 2, GLRaV-3, GRSPaV, GLRaV-1 + GRSPaV, GLRaV2 + GRSPaV, GLRaV-3 + GRSPaV and uninoculated (healthy) control. However, the chip grafting was postponed to the spring of 2009 due to spindly growth of the plantings in the experimental vineyard. After discussions with staff at FPS at Davis, CA, it was suggested that the success rate of grafting would be much higher if the plants were two budded in the spring of 2008, allowed to grow, then grafted in 2009. They suggested that first year growth is always spindly and in their experience does not provide good wood for grafting onto. The two budded vines definitely have much more girth this season as the FPS staff and other grapevine workers suggested. Wine grapes have been collected from two vineyards in Oregon and initial fruit quality work carried out. One vineyard was infected with GLRaV-2 and GRSPaV (this vineyard had been Chardonnay on rootstock (new owner not sure of the rootstock) that was then grafted with Pinot noir. Thus, this vineyard has vines with three components, rootstock, Chardonnay interblock and Pinot noir scion. The second vineyard was infected with GLRaV-3 and GRSPaV. This vineyard had self rooted Pommard clone of Pinot noir, as well as Pinot noir clone 114 on Riparia Gloire rootstock. Grapes were collected three times, each one week apart, with the last harvest at the time of commercial harvest. These grapes were analyzed for polyphenols. The results provided preliminary though limited data on the impact of viruses on the maturation and quality of Pinot Noir grapes. Methods of ADODR monitoring included stakeholders meetings, teleconferences, e-mail, and in person visits.