PD Resistant
Winegrapes Nearing
Release
Andrew Walker, Alan Tenscher,
Summaira Riaz, Cecilia Agüero, Rong
Hu, Nina Romero
Support from CDFA PD/GWSS Board, Consolidated Central
Valley Table Grape Pest and Disease Control District, the AVF,
and the Louis P. Martini Endowed Chair Funds
PD Resistance Breeding
•  Lenoir (Jacquez, Black Spanish) a V. aestivalis x V.
vinifera hybrid
•  100s of years of breeding hindered by mulitgenic
resistance – Blanc du Bois
•  We discovered single dominant gene resistance in V.
arizonica (b43-17) – genetic mapping for MarkerAssisted Selection (MAS) and physical mapping
identified members of a Serine Threonine KinaseLeucine Rich Repeat “R” gene family
Testing PdR1 – Cecilia Agüero
New gene constructs being prepared with grape promoters.
Breeding Objectives
•  Develop large seedling populations at the 97%
vinifera level in diverse, high quality vinifera
winegrape backgrounds
•  Intercross advanced high quality selections with Xf
resistance from other resistance sources
•  Use and map multigenic resistances V. arizonica/
girdiana b42-26 and others
•  Characterize additional unique resistances to make
broadly and durably resistant varieties
Marker-Assisted Selection for
PdR1
•  DNA extracted from seedlings
•  Aggressive growing techniques to get flowers and
fruit in year 2
•  Two year cycle with marker-assisted selection
(MAS)
•  Select for lack of symptoms and low bacterial levels
•  F1 = 50% vinifera; BC1 = 75%; BC2 = 88%; BC3 =
94%; BC4 = 97%
•  Optimizes classical breeding – not GMOs
Proven Potential of Classical Breeding
F8909-08 to 97% vinifera in
about 12 yrs
From peppery, herbaceous
wines with blue-purple
pigments to high quality
vinifera characters
Field Testing PD Resistant Selections
•  Wines have been made … compared with wine from
classic vinifera cultivars made at the same small scale
•  75%, 88% and 94% vinifera at Beringer/Yountville along
the Napa River have been inoculated multiple times
•  Small scale wines have been made since 2010 with
Davis and Napa fruit
•  88% and 94% in Fredericksburg TX, and Auburn AL
(88%).
•  2014 – new plots in Temecula, Napa (2X), Texas and
Alabama
Napa PdR1b (94% vinifera) vs pure vinifera
Wine Tastings
•  Need six 3-year-old trellised vines for 90 to 150lbs of
fruit •  2010 small scale 88% vinifera wines
•  2011 small scale 88 and 94% vinifera wines
Davis, Sonoma
•  2012 small scale 94% as blending varieties
Davis 2x, Healdsburg, Temecula, Napa 2x •  2013 and 2014 – small scale 97% vinifera wines
PD Resistant Selections at FPS
•  15 wine grape selections
–  Four 94% vinifera reds (last vinifera parents:
Chardonnay – 1; Lacrima Christi – 1; Petite Sirah
– 2) and three whites (Cab Sav x Carignane)
–  Eight 97% vinifera reds (last parents: Cabernet
Sauvignon - 1; Zinfandel - 3; Chardonnay – 4)
•  Multiple vine trials in Davis and Yountville – wines
made from most of the selections
•  Three rootstocks: 101-14 x F8909-08 (1) and this F1
crossed to GRN4 (2)
First Release – 07355-75
•  94% vinifera; PdR1b; red wine var., 3 yrs of wine;
Multi-vine trials in Davis and Napa
•  Performs well in repeated greenhouse screening
07355-75; U0502-38; U0502-20
•  94% vinifera; PdR1b; red wine var., 3 yrs of wine;
Multi-vine trials in Davis and Napa
•  Performs well in repeated greenhouse screening
07355-75; U0502-38; U0502-20
07355-75; U0502-38; U0502-20
Stacking PD Resistance Lines
•  2006 & 2008 crossed PdR1a x PdR1b – no
decrease in mean ELISA levels.
•  2011 crossed 97% vinifera PdR1b x 75%
vinifera b42-26 lines to create 86% vinifera
•  2014 crossed 97% vinifera PdR1b x 88%
vinifera b42-26 line to create ~ 92% vinifera
Next Phase of the Breeding Program
•  Discover, characterize, map and stack new
resistance sources –b42-26, b40-14 and BD5-117
•  Greenhouse testing results; lowest possible ELISA
readings; taxonomic and geographic relationships
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2014 Combining PD and
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Thanks!