Project Number: 5358-21000-034-34
Project Type: Specific Cooperative Agreement

Start Date: Sep 23, 2008
End Date: Sep 30, 2009

Objective:
Grapevine yellow speckle viroid 1 (GYSVd-1), Rupestris stem pitting associated virus (RSPaV) and Grapevine leafroll associated virus 3 (GLRaV-3) are frequent pathogens of grapevines. This project will examine the dynamic interactions of these pathogens in grapevines. Results will provide insight into the impact of these interactions on yield and the effect of these pathogens on horticultural properties of grapevines in the Pacific Northwest.

Approach:
The effects of single and mixed infections of GYSVd-1, GLRaV-3 and RSPaV will be monitored during the development of young grapevines. Pot trials are established to determine the magnitude of these interactions on `Okanagan Riesling¿ and `Petite Syrah (Durif)¿ varieties representing white and red grape varieties, respectively. Test plants are chip-bud inoculated from well characterized sources to ensure uniformity in the isolates of pathogen introduced alone or in combination. In addition to horticultural markers such as trunk cross sectional areas, both grape berry quality and yield will be measured. Changes in symptom expression will be monitored and berry quality and yield will be measured every year for at least two growing seasons. The concentrations of virus and viroid will be monitored as well as molecular indicators of the host response to pathogen infection. Relationships between horticultural productivity and disease status will be established. Documents SCA with Washington State University. Formerly 5358-21000-034-11S (8/2008).