Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: 11/1/2011
Publication Date: 11/9/2011
Citation: Stenger, D.C., Ramming, D.W., Rogers, E.E. 2011. Can Pierce’s disease resistance introgressed into Vitis vinifera be translocated from a resistant rootstock to a susceptible scion?. CDFA Pierce's Disease Control Program Research Symposium. p. 173-174. Interpretive Summary: Pierce’s Disease (PD) resistance from wild grapevine species has been transferred into Vitis vinifera via classical (non-transgenic) breeding. However, given the extensive number of wine, raisin, and table grape varieties susceptible to PD, introgression into each will be time consuming and costly. In this research, proof of concept experiments will be conducted in greenhouse trials to determine if PD resistance in a V. vinifera selection used as a rootstock may be translocated to susceptible V. vinifera scions.
Technical Abstract: The goal of this research is to evaluate the potential of a non-transgenic, PD resistant Vitis vinifera selection used as an experimental rootstock to confer systemic resistance to PD susceptible V. vinifera scions. Source of PD susceptible plant material will be the wine grape variety ‘Chardonnay’, known to support high populations of Xylella fastidiosa and exhibit severe PD symptoms. Source of PD resistant material will be a modified backcross generation 2 (mBC2) raisin selection with PD resistance locus PdR1 introgressed from 89-F0908 (V. rupestris X V. arizonica). Scions will be mechanically inoculated with X. fastidiosa strain Stags Leap. PD severity will be visually assessed using a nominal 0-5 rating scale where 0 corresponds to no visual symptoms and 5 corresponds to death of the plant. Following development of PD symptoms on the positive control (‘Chardonnay’ as both scion and rootstock), anticipated to be ~12-16 weeks post inoculation, tissue samples (petioles) from the point of inoculation and 25cm above the point of inoculation will be removed from each plant and X. fastidiosa titer determined by real-time PCR.