|DE LA FUENTE, LEONARDO - Auburn University|
|ALMEIDA, RODRIGO - University Of California|
Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: 10/8/2018
Publication Date: 11/24/2018
Citation: Naegele, R.P., De La Fuente, L., Almeida, R. 2018. Geographic distribution of isolate virulence in Xylella fastidiosa collected from grape in California and its effect on host resistance. CDFA Pierce's Disease Control Program Research Symposium. p. 62.
Interpretive Summary: Pierce’s Disease (PD), caused by Xylella fastidiosa (Xf) has significantly impacted the California grape industry since the 1990s. Growers lose an estimated $56 million annually in decreased production and vine replanting. Breeding efforts have resulted in new wine grape cultivars using a single source of PD resistance. This source has been effective against a few strains of Xf, but durability in the field is unknown The range in virulence (disease severity of a given isolate) of Xf in California is not known, and regional differences appear likely. Research is needed to better understand virulence variability of Xf in California and how this might impact PD resistant grape breeding. This study will evaluate Xf virulence and sustainability of PD-resistant material.
Technical Abstract: Xylella fastidiosa subsp. fastidiosa (Xf), the causal agent of Pierce’s Disease, costs California grape growers an estimated $56 million annually in management costs. Sources of resistance have been identified and a single source from V. arizonica is being incorporated into new breeding materials for wine, table and raisin grape markets. This source of resistance has been evaluated against a small set of isolates from California, but durability has not been evaluated. In California, genetic diversity of Xf is low, but virulence diversity is unknown. Regional differences among isolates appear likely, based on preliminary work. This study will evaluate variability of Xf virulence in California and potential sustainability of PD-resistant material.