Walnut varieties resistance to Xanthomonas campestris ... - Cost 873

Evaluation of resistance of cultivated walnut
varieties and selections to Xanthomonas
arboricola pv. juglandis in Greece
Tsiantos J. 1 , Vagelas I.K. 2 , Rumbos C.I. 3 , Chatzaki A. 1 , Rouskas D. 4 and Gravanis F.T. 2
1
NAGREF, Plant Protection Institute, 38001 Volos, Greece
2
Technological Education Institute of Larissa, Department of Plant Production, 41110
Larissa, Greece
3
Centre for Research and Technology-Thessaly (CE.RE.TE.TH.), Institute of Technology and
Management of Agricultural Ecosystems (I.TE.M.A.), 38500 Volos, Greece
4
NAGREF, Vardates Agricultural Research Station, Greece
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Walnut Production in Greece
Macedonia
(20%)
Thrace
(6%)
‣ 2.000.000 trees from seedling
selections
Epirus
(14%)
Thessaly
(10%)
Sterea Hellas
(14%)
Peloponnese
(30%)
30%
‣ 70% in >500 m altitude
‣ Annual production: 20.000 t *
(Tendency to be increased: new orchards are
planted in low altitude fields)
‣Main varieties: Serr, Gustine, Amigo,
Vina, Lara, Hartley, Chandler,
Crete
(6%)
Franquette, local selections
Distribution of walnut production in Greece
* Rouskas D., Akrivos J. and Zakynthinos G., 2006, J. National Research Foundation, 29 (1), p. 23-40.
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Walnut blight in Greece
Symptoms of walnut blight on nuts
‣ Walnut blight was first reported in Greece in 1951.
‣ It is considered one of the main bacterial, walnut diseases in Greece. However, there is no
detailed research on the severity and prevalence of this disease.
‣ The pathogen is endemic all over Greece and causes every year damages
mainly in nuts.
‣ Its severity depends considerably on the spring weather conditions.
‣ Control measures are cultural and, where possible, chemical (preventive spraying with copper
bactericides) but their efficacy is often inadequate.
‣ Objective of the present study: Evaluation of walnut varieties, selections and crosses
resistance to Xanthomonas arboricola pv. juglandis
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Sampling
‣ Sampling place: NAGREF, Vardates Agricultural
Research Station
‣ Sampling Date: 8 June 2008
‣ Nuts (2-4 cm ø) from 33 walnut varieties (16 lateral and 17 terminal fruit fullness
varieties), 12 selections and 13 crosses were collected
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Tested varieties, selections and crosses
Lateral fruit fullness Terminal fruit fullness Selections Crosses
Amigo Adams ΕΚ-1 S 1/1
Asley Chase D9 ΕΚ-2 S 1/6
Chandler Chase D12 ΕP-5 S 1/7
Ferjean Franquette ΕP-6 S 2/6
Fernette Geisenheim ΕΗ-28 S 3/1
Fernor Grand Jean ΕΗ-29 S 3/3
Gustine Grosvert ΕΜ-35 S 3/4
Lara Hartley ΕΜ-36 S 3/8
Mindland Lozeronne FM-5 RΖ-12
Payne Marbot FM-6 RΖ-14
Serr Meylannaise FM-16 H x G3
Sunland Milotai FM-3 F x H5
Techama Parisienne F x G7
Vina
Eliana
Eoli
Ronde de Montignac
Sibisel
Spurgcan
Leto
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Artificial infections
1. Inoculum preparation
2. Inoculation
A mixture of 4 Xaj strains isolated from naturally Bacterial inoculum was injected
infected walnut nuts in Greece was used
to nuts with a syringe (n=5)
Bacterial suspension concentration: 1-2 x 10 7 cfu ml -1 As control nuts were injected with SDW
3. Incubation
25 0 C, high humidity, plastic chambers
2 weeks
4. Evaluation
Frequeny (F)
Severity index (S)
Varietal Susceptibility Index (V.S.I.= F x S)*
* Le Lezec & Paulin, 1984, Acta Horticulturae 151, p. 277-281
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Isolation of Xaj from artificially infected nuts
1. Walnut blight spots were aseptically cut
2. Maceration of samples
3. Dilution plating of aliquots
on Brilliant cresyl blue-starch (BS) medium*
* Mulrean & Schroth, 1981, Phytopathology 71(3), p. 336-339
4. Xaj colonies identification
Starch hydrolysis zone
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Results: Frequency of infections (0-100%) (Pooled results of 2007-2008)
Lateral fruit fullness Terminal fruit fullness Selections Crosses
Amigo Adams ΕΚ-1 S 1/1
Asley Chase D9 ΕΚ-2 S 1/6
Chandler Chase D12 ΕP-5 S 1/7
Ferjean Franquette ΕP-6 S 2/6
Fernette Geisenheim ΕΗ-28 S 3/1
Fernor Grand Jean ΕΗ-29 S 3/3
Gustine Grosvert ΕΜ-35 S 3/4
Lara Hartley ΕΜ-36 S 3/8
Mindland Lozeronne FM-5 RΖ-12
Payne Marbot FM-6 RΖ-14
Serr Meylannaise FM-16 H x G3
Sunland Milotai FM-3 F x H5
Techama Parisienne F x G7
Vina
Eliana
Eoli
Ronde de Montignac
Sibisel
Spurgcan
Leto
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Results: Frequency of infections (0-100%) (Pooled results of 2007-2008)
Lateral fruit fullness Terminal fruit fullness Selections Crosses
Amigo 97.2 % Adams 100 % ΕΚ-1 58.3 % S 1/1 100 %
Asley 86.1 % Chase D9 100 % ΕΚ-2 100 % S 1/6 90 %
Chandler 91.67 % Chase D12 88.9 % ΕP-5 94.4 % S 1/7 100 %
Ferjean 100 % Franquette 91.7 % ΕP-6 88.9 % S 2/6 100 %
Fernette 100 % Geisenheim 100 % ΕΗ-28 90 % S 3/1 100 %
Fernor 100 % Grand Jean 100 % ΕΗ-29 86.1 % S 3/3 100 %
Gustine 100 % Grosvert 90 % ΕΜ-35 91.7 % S 3/4 91.7 %
Lara n.e. Hartley 63.9 % ΕΜ-36 100 % S 3/8 90 %
Mindland 94.4 % Lozeronne 100 % FM-5 100 % RΖ-12 100 %
Payne 97.2 % Marbot 58.3 % FM-6 100 % RΖ-14 83.3 %
Serr 73.9 % Meylannaise 100 % FM-16 55.6 % H x G3 76.1 %
Sunland 50 % Milotai 100 % FM-3 100 % F x H5 55.6 %
Techama 61.1 % Parisienne 100 % F x G7 100 %
Vina 100 % Ronde de Montignac 100 %
Eliana 86.1 % Sibisel 100 %
Eoli 96.7 % Spurgcan 88.9 %
Leto 100 %
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

ΕΚ1
ΕΚ2
ΕΠ5
ΕΠ6
ΕΗ28
ΕΗ29
ΕΜ35
ΕΜ36
FM5
FM6
FM16
FM3
S1/1
S1/6
S1/7
S2/6
S3/1
S3/3
S3/4
S3/8
RΖ-12
RΖ-14
HxG3
FxH5
FxG7
Amigo
Asley
Chandler
Ferjean
Fernette
Fernor
Gustine
Lara
Mindland
Payne
Serr
Sunland
Techama
Vina
Eliana
Eoli
Leto
Adams
ChaseD9
ChaseD12
Franquette
Geisenheim
Grand Jean
Grosvert
Hartley
Lozeronne
Marbot
Meylannaise
Milotai
Parisienne
Ronde Montig.
Sibisel
Spurgcan
n.e.
Results: Severity Index (0-100) (Pooled results of 2007-2008)
100
90
80
70
60
50
40
30
20
10
0
Lateral fruit fullness varieties
Terminal fruit fullness varieties
100
90
80
70
60
50
40
30
20
10
0
Selections
Crosses
n.e.: not evaluated

S1/1
S1/6
S1/7
S2/6
S3/1
S3/3
S3/4
S3/8
RΖ-12
RΖ-14
HxG3
FxH5
FxG7
Amigo
Asley
Chandler
Ferjean
Fernette
Fernor
Gustine
Lara
Mindland
Payne
Serr
Sunland
Techama
Vina
Eliana
Eoli
Leto
Adams
ChaseD9
ChaseD12
Franquette
Geisenheim
Grand Jean
Grosvert
Hartley
Lozeronne
Marbot
Meylannaise
Milotai
Parisienne
Ronde
Montig.
Sibisel
Spurgcan
n.e.
Results: Varietal Susceptibility Index (V.S.I.= F x S) (Pooled results of 2007-2008)
100
90
80
70
60
50
40
30
20
10
0
Lateral fruit fullness varieties
Terminal fruit fullness varieties
100
90
80
70
60
50
40
30
20
10
Selections
Crosses
0
ΕΚ1
ΕΚ2
ΕΠ5
n.e.: not evaluated
ΕΠ6
ΕΗ28
ΕΗ29
ΕΜ35
ΕΜ36
FM5
FM6
FM16
FM3

Class of Susceptibility (A–E) (Pooled results of 2007-2008)
Lateral fruit fullness Terminal fruit fullness Selections Crosses
Amigo Adams ΕΚ-1 S 1/1
Asley Chase D9 ΕΚ-2 S 1/6
Chandler Chase D12 ΕP-5 S 1/7
Ferjean Franquette ΕP-6 S 2/6
Fernette Geisenheim ΕΗ-28 S 3/1
Fernor Grand Jean ΕΗ-29 S 3/3
Gustine Grosvert ΕΜ-35 S 3/4
Lara Hartley ΕΜ-36 S 3/8
Mindland Lozeronne FM-5 RΖ-12
Payne Marbot FM-6 RΖ-14
Serr Meylannaise FM-16 H x G3
Sunland Milotai FM-3 F x H5
Techama Parisienne F x G7
Vina
Eliana
Eoli
Ronde de Montignac
Sibisel
Spurgcan
Leto
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Class of Susceptibility (A–E) (Pooled results of 2007-2008)
Lateral fruit fullness Terminal fruit fullness Selections Crosses
Amigo A Adams C ΕΚ-1 A S 1/1 C
Asley A Chase D9 B ΕΚ-2 B S 1/6 B
Chandler B Chase D12 B ΕP-5 B S 1/7 C
Ferjean B Franquette A ΕP-6 B S 2/6 C
Fernette B Geisenheim B ΕΗ-28 B S 3/1 D
Fernor B Grand Jean B ΕΗ-29 A S 3/3 C
Gustine B Grosvert C ΕΜ-35 B S 3/4 C
Lara n.e. Hartley A ΕΜ-36 B S 3/8 C
Mindland B Lozeronne B FM-5 B RΖ-12 B
Payne B Marbot B FM-6 B RΖ-14 A
Serr B Meylannaise D FM-16 A H x G3 B
Sunland A Milotai D FM-3 C F x H5 A
Techama A Parisienne B F x G7 C
Vina B Ronde de Montignac D
Eliana A Sibisel C
Eoli B Spurgcan A
n.e.: not evaluated
Leto
B
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Class of Susceptibility (A–E) (Pooled results of 2007-2008)
Lateral fruit fullness Terminal fruit fullness Selections Crosses
Amigo A Adams C ΕΚ-1 A S 1/1 C
Asley A Chase D9 B ΕΚ-2 B S 1/6 B
Chandler B Chase D12 B ΕP-5 B S 1/7 C
Ferjean B Franquette A ΕP-6 B S 2/6 C
Fernette B Geisenheim B ΕΗ-28 B S 3/1 D
Fernor B Grand Jean B ΕΗ-29 A S 3/3 C
Gustine B Grosvert C ΕΜ-35 B S 3/4 C
Lara n.e. Hartley B ΕΜ-36 B S 3/8 C
Mindland B Lozeronne B FM-5 B RΖ-12 B
Payne B Marbot B FM-6 B RΖ-14 A
Serr B Meylannaise D FM-16 A H x G3 B
Sunland B Milotai D FM-3 C F x H5 A
Techama B Parisienne B F x G7 C
Vina B Ronde de Montignac D
Eliana A Sibisel C
Eoli B Spurgcan A
n.e.: not evaluated
Leto
B
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Class of Susceptibility (A–E) (Pooled results of 2007-2008)
Lateral fruit fullness Terminal fruit fullness Selections Crosses
Amigo A Adams C ΕΚ-1 A S 1/1 C
Asley A Chase D9 B ΕΚ-2 B S 1/6 B
Chandler B Chase D12 B ΕP-5 B S 1/7 C
Ferjean B Franquette A ΕP-6 B S 2/6 C
Fernette B Geisenheim B ΕΗ-28 B S 3/1 D
Fernor B Grand Jean B ΕΗ-29 A S 3/3 C
Gustine B Grosvert C ΕΜ-35 B S 3/4 C
Lara n.e. Hartley B ΕΜ-36 B S 3/8 C
Mindland B Lozeronne B FM-5 B RΖ-12 B
Payne B Marbot B FM-6 B RΖ-14 A
Serr B Meylannaise D FM-16 A H x G3 B
Sunland B Milotai D FM-3 C F x H5 A
Techama B Parisienne B F x G7 C
Vina B Ronde de Montignac D
Eliana A Sibisel C
Eoli B Spurgcan A
n.e.: not evaluated
Leto
B
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Conclusions
Some varieties and crosses seem to be particularily susceptible
under the experimental conditions tested :
Meylannaise, Milotai, Ronde de Montignac, S 3/1
Some varieties and crosses appear to be less susceptible
under the experimental conditions tested :
Amigo, Asley, Eliana, Franquette, Spurgcan, EK-1, EH-29, FM-16, RZ-14, FxH 5
The selections tested seem to be less susceptible and promising
Artificial inoculations of nuts is an easy and fast way to evaluate resistance
to walnut blight
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens

Other Research
‣ Selection of Xaj isolates from different geographical areas of Greece
Biochemical characterization of the Xaj isolates with conventional tests
Confirmation of the pathogenicity of the Xaj isolates by hypersensitivity reaction
on tobacco leaves
Future Research
‣ The evaluation of the resistance of the varieties, selections and crosses
will continue next year
‣ Copper sensitivity of the collected Xaj isolates
‣ The characterization of the genetic variability of the greek Xaj isolates
Thank you!
COST 873, WG 1-4 Joint Meeting, 20-22 October 2008, Athens