Virus Effects on Vine Growth and Fruit Components of Three
California ‘Heritage’ Clones of Cabernet Sauvignon
Deborah A. Golino*1, James Wolpert2, Susan T. Sim1, Jason
Benz2, Michael Anderson2, and Adib Rowhani1
Department of Plant Pathology, 2 Department of Viticulture and Enology,
University of California, Davis, California, 95616, U.S.A. email: [email protected]
1
Vine growth and fruit components of three California ‘Heritage’ Cabernet Sauvignon clones were compared with their original virus-infected parent selections. The heritage clones were field selections from
highly regarded vineyards in Napa Valley which were known to have virus problems. They were each
treated by meristem shoot tip culture (Golino et al, 2001) to eliminate virus. Clone FPS 29, the NiebaumCoppola clone, was from old plantings near the Niebaum-Coppola winery which provided premium quality
grapes. Clone FPS 30, the Disney Silverado clone, was from an old vineyard off Silverado trail believed to
be planted with the See clone of Cabernet. Clone 31, the Mondavi clone, was collected from 50-year old
vines in the To-Kalon vineyard.
Materials and Methods
Wood for each Heritage clone came from the Foundation vineyard at Foundation Plant Services, UC
Davis. For each new clone, wood from the original virus-infected source (VIS) was collected from the UC
Davis Grapevine Virus Collection (Golino, 1992). All three original virus-infected parent selections were
infected with Grapevine leafroll virus type 3 (GLRV-3), Grapevine virus B (GVB), and Grapevine fleck
virus (GFkV). The three pairs of virus-infected parent selections with their healthy progeny clones totaled
six different treatments and were: VIS 29 & FPS 29 (Niebaum-Coppola); VIS 30 & FPS 30 (Disney Silverado); and VIS 30 & FPS 31(Mondavi).
The trial was established at the UC Oakville Station in Napa Valley with 1.5 x 2 meter (vine x row) spacing in rows oriented North-South. Budwood was field budded onto certified 101-14 Mgt in spring, 2002, in
a randomized complete block design with 5 replications and 12 vines/ treatment/ replication. Vines were
trained to a bilateral cordon on a vertical shoot positioned (VSP) trellis, and spur-pruned.
Each plant was observed for leafroll symptoms in the fall. Selected vines were virus tested to confirm
infection and monitor possible spread. Vine yield components (cluster number, cluster weight, clusters
per shoot, berries per cluster and berry weight), fruit composition (Brix, pH, titratable acidity) and vegetative growth parameters (pruning weight and shoot weight) were measured for two years when vines were
three and four years old before they were fully mature. Subsequently, the virus-infected selections were
removed due to concern that leafroll disease might spread to adjacent clones and trials.
Results
Symptom Observations and Vine Growth: Typical leafroll virus symptoms were observed in all original virus-infected selections. In general, the virus-infected selections required more replanting and took longer
to establish trunks and cordons than healthy clones. Vine growth, as indicated by pruning weight, was significantly reduced by virus infection in two clones (Figure 1). Notably, VIS 29 was severely stunted; it had
58% less pruning weight compared to FPS 29. Selection VIS 31 had 24% less pruning weight compared
to FPS 31.
Yield: Yield was significantly reduced by virus infection in two clones; 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). The number of clusters/vine was significantly reduced by virus infection in one clone (28.8, 20.5 for FPS 29, VIS 29, respectively).
Proceedings of the 2nd Annual National Viticulture Research Conference • July 9 –11, 2008 • University of California, Davis
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Fruit composition: Sugar content was significantly lower in all virus-infected selections by approximately 3 to
4 ° Brix (P< 0.0001). There was also a small but statistically significant difference in sugar content between
healthy clones; FPS 29 had lower sugar content than FPS 30 and 31 (24.2, 24.8, 24.8° Brix, respectively)
(Figure 3). Titratable acidity (TA) was significantly higher in virus-infected vines compared to healthy in one
clone (7.7, 6.3 g/L for VIS 31, FPS 31 respectively) (Figure 4).
Discussion
The effects of virus infection on each Heritage selection varied significantly. In the case of FPS 30/VIS 30
little effect was seen on yield in contrast to FPS 29/VIS 29 and FPS 31/VIS 31. This may be a result of clonal
difference in virus response. However, all three Cabernet Sauvignon selections came from different field
sources. Therefore, although they are infected with the same species of virus (GLRV-3, GVB, AND GFkV),
there may be strain differences between those species affecting the severity of symptoms. Different strains
of each species of GLRV would be expected by plant virologists to demonstrate variation in symptoms severity. This data provides some evidence for that hypothesis.
References
Golino, D. A. 1992. The Davis Grapevine Virus Collection. American Journal of Enology and Viticulture
43(2):200-205.
Golino, D.A., Sim, S.T.,. Bereczky, J. and Rowhani, A.. 2001. The Use of Shoot Tip Culture in Foundation
Plant Materials Service Programs. Combined Proceedings of the International Plant Propagators
Society, Volume 50: 568-573.
Figure 2. Yield, mean of 2 years
Figure 1. Pruning weight, mean of 2 years
Virus-infected parent
Healthy tissue cultured progeny
3.5
1.20
3
1.00
2.5
kg/vine
kg/vine
1.40
0.80
0.60
1.5
1
0.20
0.5
0
VIS 29 & FPS 29
VIS 30 & FPS 30
VIS 31 & FPS 31
VIS 29 & FPS 29
Cabernet Sauvignon clone
Virus-infected parent
VIS 30 & FPS 30
VIS 31 & FPS 31
Cabernet Sauvignon clone
Figure 3. Sugar content, mean of 2 years
Figure 4. Titratable acidity, mean of 2 years
Healthy tissue cultured progeny
9
25
Virus-infected parent
Healthy tissue cultured progeny
8
24
7
6
23
g/ L
degrees Brix
Healthy tissue cultured progeny
2
0.40
0.00
Virus-infected parent
22
21
5
4
3
2
20
1
19
VIS 29 & FPS 29
VIS 30 & FPS 30
0
VIS 31 & FPS 31
VIS 29 & FPS 29
Cabernet Sauvignon clone
VIS 30 & FPS 30
Cabernet Sauvignon clone
VIS 31 & FPS 31
Proceedings of the 2nd Annual National Viticulture Research Conference • July 9 –11, 2008 • University of California, Davis
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