Creating Xylella Resistant Grapevines by Conventional BreedingAndy Walker, Alan Tenscher, Summaira Riaz& David RammingSupport from CDFA PD/GWSS Board, the AVF, and the Louis P. Martini Endowed Chair Funds

History of Breeding for PD Resistance• Muscadine grapes have excellent PD resistance, but physically and genetically hard to introgress resistance into vinifera

• Bunch grape breeding in the southeastern US - (Blanc du Bois, BD5-1) has been hindered by intense fungal disease pressure and quantitative inheritance of PD resistance from conventional sources

PD Resistance of Olmo’s Mexico Collections

9R7I8S

4R,2I,1S

8R,0S

5R4I1S

1R,0S

Sources of Xf resistance

• b43-17 – (V. arizonica/candicans) from Monterrey, Mexico – resistance is inherited as a single dominant gene

Sources of Xf resistance

• Markers linked to PdR1 from b43-17 have different alleles in b40-14 and b42-26

• Many more V. arizonica and V. girdiana forms have been collected for testing

Mapping and Characterizing PD Resistance

The PdR1 resistance locus exists in V. arizonica b43-17

All progeny from this plant are resistant to Xf; the F8909 pop. (V. rupestris x b43-17)

F8909-08 and F8909-17 have been used in breeding and mapping Xf resistance

D8909-15 x F8909-17 = 9621 population

Mapping and Characterizing PD Resistance

Fine scale mapping has positioned PdR1 within

1cM of markers on LG 14

PdR1 from F8909-17 and F8909-08 map

differently and represent either chromosome

of the PdR1 locus – PdR1a and PdR1b from

b43-17

VVCh14-30VVCh14-28VVCh14-29,

PdR1b

VVCh14-02

VVCh14-10UDV095,VVCh14-09

VMCNg2b7.2,VVCh14-27

UDV025

0.26

0.23

0.39

0.45

6.12

VMCNg1e1

VVC62VVIP05VVIQ32

UDV050VMC9c1

VMC1e12VVC34VVIP22VrZAG112VMC6c10VMC5b3UDV033VMC2a5VVIV69ctg1026876VMCNg2b7.2 VVCh14-27VVCh14-28 VVCh14-29VVCh14-30VVCh14-70PdR1bVVCh14-02VVCh14-10VVCh14-09UDV95UDV025ctg1025882VVIS70VVIP26VMC6e1VMCNg1g1.1VVIN94ctg101093VVIN70

6.22

3.151.74

7.41

0.425.01

7.07

4.363.993.384.783.471.094.624.310.263.660.230.390.456.120.770.530.030.810.542.400.981.33

F8909-0804190 population

3.66

VVCh14-70

SCU15

VMCNg1e1

UDV050

VMC9c1

VVIO32VMC1e12

VVC34VMC9f4-1VVIP22VrZAG112VMC6c10VMC5b3UDV33VMC2a5VVIV69VMCNg2b7.2VMCNg3h8VVCh14-29VVCh14-70PdR1aA010VVCh14-56UDV95VVIN64ctg1025882VVIS70VVIP26VMC6e1VMCNg1g1.1UDV025ctg1010193

5.95

8.22

3.96

4.75

3.40

11.873.332.815.540.423.672.801.384.960.983.400.970.380.143.693.180.210.290.341.641.048.25

F8909-179621

VMCNg3h8,VVCh14-29

PdR1a

VVCh14-56. A010

UDV95,

VMCNg2b7.2

VVIN64

0.98

0.97

0.38

0.14

3.69

3.40

VVCh14-70

8909-19 S 8909-08 R

Breeding Objectives• Breed PD resistant wine grapes by backcrossing Xf resistant selections to high quality V. vinifera wine grape cultivars.

• Characterize Xf resistance and wine grape quality traits (color, tannin, ripening dates, flavor, productivity, etc).

• Work with David Ramming to accomplish the same goals with table and raisin grapes.

Breeding Objectives• Develop large seedling populations at the 94% and 97% vinifera level in many high quality vinifera wine and table backgrounds

• Intercross advanced high quality selections with Xf resistance from multiple sources

• Introgress in powdery mildew resistance

• Develop genetic markers for fruit and wine quality

Backcross BreedingBegin with a resistance source crossed to V. vinifera

– That F1 is 50% V. vinifera– Cross back to V. vinifera – 75% mBC1– Cross back to V. vinifera – 87.5% mBC2– Cross back to V. vinifera – 93.75% mBC3

– Cross back to V. vinifera – 96.89% mBC4

– 3 yr cycle with marker-aided selection (MAS)

2008 Progress at 93.75% V. vinifera (mBC3)• Planted about 400 seedlings (some fruited!), will produce 97% (mBC4) seed in 2009

• Propagated 8 strong seedlings (6 to 7 vine reps) to wide spacings and Wye trellis for wine lots in Fall 2009

Progress at 93.75% V. vinifera (mBC3)

07329-35 0505-01 x Chardonnay 07329-37 0505-01 x Chardonnay 07335-075 0505-01 x Petite Sirah 07355-12 0505-01 x Petite Sirah 07355-42 0505-01 x Petite Sirah 07713-43 F2-35 x 0502-48 07713-51 F2-35 x 0502-48 07713-55 F2-35 x 0502-48

F8909-08 = V. rupestris x V. arizonica b43-17504-49 = B90-116 x 8909-08 (PdR1b)A81-17 = A38-17 x 504-490502-48 = A81-138 x Chardonnay0505-01 = A81-138 x Cabernet Sauvignon

Resistant Type

Vinifera Parent of Resistant Type

Vinifera Types used in 2008 crosses

# Seeds Produced

A. U0502 Chardonnay F2-7 (Cab x Carignane) 262 U0505 Cabernet Sauvignon Tannat 694 B. 06324 Chenin blanc Airen, Cabernet

Sauvignon, Chardonnay, Tannat

484

06372 Malaga Rosada Clairette blanche, Tannat

946

06381 F2-7 (Cab x Carignane) Tannat 151

2008 crosses to produce (A) = 93.75% vinifera PdR1b (F8909-08) and (B) = 87.5% vinifera PdR1a resistance (F8909-17).

Resistant Type

Vinifera Parent of Resistant Type

Vinifera Types used in 2008 crosses

# Seeds Produced

A. U0502 Chardonnay 06353, e78 allele pattern 82 U0505 Cabernet Sauvignon 06717, e78 allele pattern 138 B. A81-17 A38-7 Karadzhandal 564

2008 crosses to produce: A) = 90.6% vinifera PdR1b (F8909-08) with Run1 powdery mildew resistance; and B) = 87.5% vinifera PdR1b resistance (F8909-08) with vinifera PM resistance.

PD Resistant

Type Other Parents # Seeds

Produced 03300-048 06301 (101-14 x GRN-4),

Wyoming Riparia, Riparia Gloire, 44-53Mgt

1,397

2008 rootstock crosses to combine PD and nematode resistance.

Resistant Type

Vinifera Parent of Resistant Type

Vinifera Types used in 2008 crosses

# Seeds Produced

A. 06324 Chenin blanc Airen, Cabernet Sauvignon,

Chardonnay, Tannat 484

06372 Malaga Rosada Clairette blanche, Tannat 946 06381 F2-7 (Cab x Carignane) Tannat 151 B. 06339 F2-35 (Cab x Carignane) Malaga Rosada, Tannat 325 C. 0098-03 Table grapes Cabernet Sauvignon,

Chardonnay 324

04394 Table grapes Cabernet Sauvignon, Clairette blanche, F2-35, Tannat

1,130

D. b42-26 None F2-35 827

2008 Crosses: 87.5% vinifera progeny (A) PdR1a (F8909-17); (B) arizonica b40-14 (06339); (C) shuttleworthii (0098-03 – 75% vinifera and 04394 – 50% vinifera); and (D) arizonica/girdiana b42-26 (50% vinifera progeny).

87.5% V. vinifera / 50% Chardonnay

2008 Winegrape Evaluations

Cultivar/ Selection Parentage

% vin

2008 Bloom Date

Berry Size (g)

Avg Clstr Wt. (g)

Ripening Season

Prod 1=v low 9=v hi

Barbara Historic 100 5/5 2.4 290 Late 6 Zinfandel Historic 100 5/5 2.6 405 Mid 7 U0501-12 A81-138 x Syrah 87.5 5/11 1.0 160 Late 4 U0502-01 A81-138 x Chardonnay 87.5 5/5 2.0 210 Mid-late 4 U0502-10 A81-138 x Chardonnay 87.5 5/5 1.7 275 V early 8 U0502-20 A81-138 x Chardonnay 87.5 5/10 2.0 201 Late 8 U0502-26 A81-138 x Chardonnay 87.5 5/9 2.1 375 Mid-late 6 Lenoir V. aestivalis hybrid <50 5/16 0.8 201 Late 6

Reference cultivars and select 87.5% vinifera progeny with PdR1.

2008 Winegrape Evaluations

Cultivar or Selection

L-malic acid (g/L) °B

K (mg/ mL) pH

TA (g/

100mL) YAN

(mg/L) catechin (mg/L)

tannin (mg/L)

Total antho-cyanins (mg/L)

Barbara 2.83 25.0 2170 3.36 0.87 431 31 201 300 Zinfandel 2.43 23.5 1870 3.55 0.62 191 34 322 386 U0501-12 3.22 27.2 2020 3.51 0.74 3.98 48 781 1161 U0502-01 7.36 23.3 3240 3.70 0.96 567 81 364 530 U0502-10 4.36 22.3 1800 3.47 0.82 305 73 565 828 U0502-20 4.94 24.0 2600 3.62 0.90 544 - - - U0502-26 5.55 24.3 2420 3.64 0.91 699 65 225 811 Lenoir 5.54 28.7 3050 3.63 0.83 230 160 405 2396

Juice and wine analysis courtesy of ETS Laboratories, St. Helena, CA.

Variety/ Selection

Group Total

Lo Score

Hi Score

2007 Total

U0502-20 34.0 2 5 NA

Syrah 32.8 2 4 NA

Chardonnay 32.3 2 5 NA

U0501-12 30.5 1 4 33.5

U0502-10 30.5 1 4 27

Lenoir 26 1 4 26

Pinot noir 21.5 1 3 20

U0502-01 20.3 1 3 24

Tasting results of 2007 wines (1= poor to 5 = very good). There were 10 faculty and staff tasters. Cabernet Sauv., Midsouth and U0502-07 and -01 not fermented in 2008

2008 Wine Evaluations 87.5% vinifera

Thanks!