Current UC Viticulture Research
|Principal Investigator||Deborah Golino|
|Project Title||Virus Effects on Vine Growth and Fruit Components of Three California ‘Heritage’ Clones of Cabernet Sauvignon|
Vine growth and fruit components of three California ‘Heritage’ Cabernet Sauvignon clones were compared with their original virus-infected parent sources. The heritage clones were field selections from highly regarded vineyards in Napa Valley known to have virus problems.
Brix was significantly lower, by an average –4.0, in all three original virus-infected sources (VIS) compared to their treated progeny (Figure 1).
Virus effects on yield, pruning weight, and titratable acidity varied with clone. Two original selections, had significantly lower yield than their treated progeny. VIS 29 had a 45% yield reduction compared to FPS 29; VIS 31 had a 30% yield reduction compared to FPS 31. Also, yield between healthy clones was significantly different; yield of FPS 29 and FPS 30 was almost double that of FPS 31 (3.1, 3.0, 1.7 kg/vine, respectively (Figure 2).
Titratable acidity was increased in the virus-infected selection in one pair, VIS31/FPS31, but not the other two (Figure 3). This may be a result of clonal difference in virus response or strain difference between viruses.
The virus-infected selections were removed due to concern that leafroll disease might spread to adjacent clones and trials.
Although all three Cabernet Sauvignon selections were infected with the same virus species (GLRaV-3, GVB, and GFkV), they came from diverse sources. There may be strain differences between those species affecting the severity of symptoms. Different strains of each species of GLRaV would be expected by plant virologists to demonstrate variation in symptom severity. This data provides some evidence for that hypothesis.
California Observation of Leafroll Effects and Field Spread: Dr. Deborah Golino, Cooperative Extension Specialist, Department of Plant Pathology, UC Davis, discusses her observations of leafroll effects and field spread over the last 15 years in this videotaped presentation.
|Researchers and Cooperators|
Golino, D. A. 1992. The Davis Grapevine Virus Collection. American Journal of Enology and Viticulture 43(2):200-205. Abstract
Osman, F., Leutenegger C., Golino D. and Rowhani, A. 2008. Comparison of low-density arrays, RT-PCR and real-time TaqMan RT-PCR in detection of grapevine viruses. J Virol Methods149(2):292-9. Epub 2008 Mar 10.
Rowhani, A., 1992. Use of (ab)2 antibody fragment in ELISA for detection of grapevine viruses. Am. J. Enol. Vitic. 43:38–40. Abstract
Rowhani, A., Biardi, L., Johnson, R., Saldarelli, P., Zhang, Y.P., Chin, J., Green, M., 2000. Simplified sample preparation method and one-tube RT-PCR for grapevine viruses. In: Proceedings of XIII International Council for the Study of Viruses and Virus-Like Diseases of the Grapevine, Adelaide 2000,p. 82.