1. 1
Name : Patel S. B.
Major advisor: Dr. J. A. Patel
Degree : M. Sc. (Agri.)
Course No. : PBG 699
Date : 21–1–06
Time : 10:00 a.m.
Breeding for
bacterial wilt (Ralstonia solanacearum L)
resistance in tomato
2. 2
Content
• Introduction
• Mechanism of Resistance
• Genetics of Resistance
• Screening Methods
• Source of Resistance
• Breeding Methods
• Achievements
• Conclusion
• Future Thrust
4. 4
Botanical Name : Lycopersicon esculentum Mill.
Family : Solanaceae (2n = 2x = 24)
Origin : Peru, South America
Tomato
5. 5
Table 1: Area and production
Tomato Area Production
India 0.55 million ha 8.4 million tonnes
Gujarat 0.23 lakh ha 4.21 lakh tonnes
Anon.(2004)
6. 6
CAUSAL ORGANISM
• Name : Ralstonia solanacearum (Smith) Yabuuchi et al.
• Synonyms : Bacterium solanacearum (Smith) Chester
Burkholderia solanacearum (Smith) Yabuuchi et al.
Pseudomonas solanacearum (Smith) Smith
• Taxonomic position : Bacteria: Gracilicutes
• Common Name : Southern Bacterial Wilt of Tomato
• Morphology : Gram negative rod, 0.5 – 1.5 um in length,
Single polar flagellum, The positive staining reaction
for poly-B-hydroxybutyrate granules with Sudan
Black B or Nile Blue distinguishes R.solanacearum
from Erwinia species.
• Important Hosts : Musa Spp., Tobacco, Potatoes.
• Minor Hosts : Groundnut, Cotton, Castor, Beans, Ginger
EPPO
7. 7
Race 1 Race 2 Race 3
Affected
Crop
tobacco, tomato,
potato, diploid
banana and other
solanaceous crops
and weed
triploid
banana and
Heliconia Spp.
tomato and
potato
Cause temperature
optimum
35-37 0C
temperature
optimum
35-37 0C
temperature
optimum
27 0C
Table 2: Biology
EPPO
8. 8
Table 3: Geographical distribution
Race 1 Race 2 Race 3
Asia Armenia,Bangladesh,India
(widespread), Bhutan, Cambodia,
Indonesia (widespread), Iran, Japan,
Korea, China (widespread), Taiwan,
Thailand, Pakisthan, Shri Lanka.
India (West Bengal),
Indonesia, Malaysia, Shri
Lanka, Thiland, Viet Nam.
India, Indonesia, Iran,
Japan, Korea, China ,Israel,
Nepal.
Africa Ethiopia, Kenya, Malawi, Mauritius,
Nigeria, Somalia, Russia, South
Africa, Swaziland, Tanzania, Uganda,
Zambia, Zimbabwe.
Ethiopia, Libya, Malawi,
Nigeria, Senegal, Somalia.
Algeria, Burundi, Egypt,
Kenya, South Africa,
Zambia.
North
America
Canada, Mexico, U.S.A. Mexico, U.S.A.(Florida) Mexico
Central
America and
Caribbean
Cuba, El Salvador, Haiti, Jamaica,
Panama, Paraguay.
Costa Rica, Cuba, El
Salvador, Haiti, Jamaica,
Nicaragua, Panama. Trinidad
and Tobago.
Costa Rica
South
America
Argentina, Brazil,Colombia, Ecuador,
Guyana, Peru, Venezuela.
Argentina, Brazil,Colombia,
Ecuador, Guyana, Peru,
Venezuela.
Argentina, Brazil, Peru.
Oceania Australia (widespread), Fiji, Guam,
Micronesia, New Zealand, Samoa.
Absent Australia
European
Union
Absent Present Present
EPPO
12. 12
Table 4: Pathogenic aggressiveness of six strain of Ralstonia solanacearum.
Strain Disease incidence
10 94 %
W2 91 %
8 89 %
1B 89 %
H4 88 %
K 60 80 %
Florida Chellemi. (1994)
13. 13
SYMPTOMS
• Bacterial masses prevent water flow from the roots
to the leaves, resulting in plant wilting.
• Youngest leaves are the first to be affected and have
a flabby appearance.
• Under less favourable conditions, the disease
develops less rapidly, stunting may occur and large
number of adventitious roots are produced on the
stem.
• Under favorable conditions quick and complete
wilting of plant.
14. 14
Fig. 4: The vascular tissues of the stem show a brown discoloration.
15. 15
Fig. 5: Vascular bundle tissue showed color discoloration in wilted tomato
16. 16
Fig. 6: Bacterial wilt disease of tomato caused by Ralstonia solanacearum
Wilted Plants
Healthy Plants
17. 17
Fig.7:
If the stem is cut
crosswise, drops of white
or yellowish bacterial
ooze may be visible.
Bacterial ooze
18. 18
Epiphytotic Condition for Disease Occurrence
• Infested soils and surface water, including
irrigation water are the main source of
inoculums.
• High temperature and high soil moisture are
the major factors associated with high
bacterial wilt incidence and severity.
24. 24
Mechanism of Resistance
• Immune:
Means exempt 100% freedom from infection.
Pathogen can not establish parasitic relationship with the host even
under most favourable condition.
• Tolerance:
Inherent or acquired capacity to endure disease and to give
satisfactory returns.
• Escape:
Certain varieties of crop plants which undergoes development and
maturation, may complete their life cycle before maximal infection
occurs.
• Resistance:
Resistance is relative term and measured by using susceptible
cultivars of the same species as checks, may not be observed in the most
favorable condition.
26. 26
Disease rating scale used for calculation of disease severity
0 : No symptoms
1 : 1 leaf wilted or partially wilted
2 : 2- 3 leaves wilted or partially wilted
3 : More leaves wilted
4 : All leaves wilted
5 : Plant dead
ARC RESEARCH REPORT Anon (1998)
27. 27
TYPES OF RESISTANCE
(i) Vertical (Specific ) resistance
Specific resistance of host to the particular race of a
pathogen governed by mono or oligo genes.
(ii) Horizontal (General) resistance
The resistance of a host to most of the prevailing
races of pathogen is called horizontal resistance
(non-specific resistance or minor gene resistance)
and governed by monogene/oligogene/polygenes.
29. 29
Table 8: Quadratic check resulting from interaction between two alleles at one
locus in the host and two alleles at one locus in the pathogen
Pathogen Host
RR / Rr rr
AA / Aa Resistance ( I ) Susceptible ( C )
aa Susceptible ( C ) Susceptible ( C )
Flor (1942)
I : Incompatible (Resistant) ; C : Compatible (Susceptible)
RR : Homozygous resistant; Rr : Heterozygous resistant; rr : Homozygous susceptible
AA : Homozygous avirulant; Aa : Heterozygous avirulant; aa : Homozygous virulant
30. 30
Table 9: Segregation of plants in F2 populations against bacterial wilt in tomato.
F2
Population
Susceptible
Plants (s)
Resistant
Plants (r)
χ 2
Value (3:1)
UHF-265 X BL- 342- 1 115 33 0.577
UHF-265 X EC- 191536 104 42 1.105
UHF-120 X BL- 342- 1 112 30 1.136
UHF-120 X EC- 191536 115 29 1.815
Pooled 446 134 1.113
Solan Thakur et al. (2004)
31. 31
Table 10: Segregation of plants in backcross populations against bacterial
wilt in tomato
Susceptible
Plants (s)
Resistant
Plants (r)
Expected
ratio (s:r)
χ 2
Value
B1 Populations
(UHF-265 X BL- 342- 1) X UHF-265 56 1 1:0 -
(UHF-265 X EC- 191536) X UHF-265 48 3 1:0 -
(UHF-120 X BL- 342- 1) X UHF-120 52 0 1:0 -
(UHF-120 X EC- 191536) X UHF-120 55 2 1:0 -
Pooled 211 6 1:0 -
B2 Populations
(UHF-265 X BL- 342- 1) X BL- 342- 1 32 23 1:1 1.473
(UHF-265 X EC- 191536) X EC- 191536 35 24 1:1 2.051
(UHF-120 X BL- 342- 1) X BL- 342- 1 26 30 1:1 0.286
(UHF-120 X EC- 191536) X EC- 191536 33 22 1:1 2.200
Pooled 126 99 1:1 3.240
Solan Thakur et al. (2004)
32. 32
Table 11: Segregation of resistance of Hawaii 7996 wilt percentage of plants
34 days after inoculation.
1 Hypothesis of a 3:1 segregation of the F2 compared to the wilting percentages of Floradel in each repeated
block.
The hypothesis was accepted at the 5% level when χ2 value was <3.84.
Grimault et al. (1995)
Block % Wilting
χ 2 test
Hawaii
7996
Floradel F2 Actual F2
Expected 1
1 0 90.9 23.0 22.8 0.005
2 0 94.9 21.4 23.7 1.150
3 0 91.9 21.4 23.0 0.520
4 0 89.2 24.9 22.3 1.480
5 0 86.5 24.6 21.5 2.240
33. 33
Table 12: Total and percentage of healthy plants after inoculation with the
bacterial wilt pathogen in two experiments.
Bradenton, Florida, U.S.A. Scott et al. (1989)
Genotype Generation Total Plants Healthy
Plants (%)
Expected
Ratio
χ 2 P
Experiment 1 (Summer-Fall 1986)
Walter (W) P1 18 0 - - -
H 7998 (H) P2 25 69.0 - - -
W x H F1 21 75.7 - - -
W (W x H) BCP1 53 52.3 1:1 0.090 0.90 -0.95
H (W x H) BCP2 44 81.0 - - -
(W x H)2 F2 249 58.7 3:1 35.568 >0.001
Experiment 2 (Fall 1987-Spring 1988)
Walter (W) P1 25 16.0 - - -
H 7998 (H) P2 22 95.3 - - -
W x H F1 24 72.0 - - -
W (W x H) BCP1 51 55.0 1:1 0.490 0.2. -0.50
H (W x H) BCP2 105 95.3 - - -
(W x H)2 F2 97 83.3 3:1 3.742 0.05-0.10
34. 34
Table 13: Analysis of variance for host plant resistant to Ralstonia solanacearum
Source of
variation df
Mean square
Strain
UW -25
Strain
UW -258
Strain
UW -256
Strain
UW –275
Strain
UW -255
Strain
UW -130
Strain
UW -8
Replication 3 28.13*** 7.68*** 31.54*** 2.74*** 47.76*** 7.98*** 48.14***
Entries 27 4.46*** 8.60*** 10.52*** 32.4*** 20.31*** 37.12*** 30.30***
Parents(P) 6 6.49*** 15.39*** 16.55*** 39.21*** 35.23*** 50.51*** 37.97***
P vs C 1 1.35 NS 16.49*** 5.62*** 46.16*** 1.01 NS 39.40*** 24.95***
Crosses 20 4.01*** 6.17*** 9.36*** 29.72*** 16.80*** 32.99*** 28.25***
GCA 6 11.36*** 12.35*** 27.04*** 82.49*** 42.94*** 92.37*** 81.49***
SCA 14 0.86 NS 3.52*** 1.78 NS 7.11*** 5.60** 7.57*** 5.45***
Error 81 1.02 0.57 1.49 1.99 2.08 1.19 1.30
CV (%) 14.02 28.27 30.71 30.71 22.52 21.49 20.47
Costa Rica Gonzalez et al. (1995)
GCA and SCA refer to general and specific combining ability, respectively.
NS,**,*** Non Significant or significant at P= 0.01 or 0.001, respectively.
37. 37
Screening Methods
• Stem-puncture inoculation technique
Four week old seedling are inoculated using the stem-
puncture technique, which consist of forcing a sharp
needle into the stem through a drop of bacterial
suspension, that has been placed in the axils of the second
or third expanded leaf below the stem apex.
• Infested soil technique
Soil sample is to be collected from the base of plant
with symptoms of bacterial wilt, passes through a mesh
screen to remove plant debris, and stored in plastic
containers.
The inoculum's density is to be determined before
each replication using a modified soil dilution technique.
38. 38
Disease severity of LB-6 and K-60 isolate at 26.6 0C and 32.2 0C
LB- 6
0
20
40
60
80
100
120
Bonnie Best Venus 7580 1169
Lines
Disease
Index
26.6 C
32.2 C
K- 60
0
20
40
60
80
100
120
Bonnie Best Venus 7580 1169
Lines
Disease
Index
26.6 C
32.2 C
New York Krausz et al. (1975)
Bonnie Best – Susceptible
Venus, 7580, 1169- Resistant
39. 39
Table 15: Relative reaction of different wilt resistant lines to an Indian isolate of Pseudomonas
solanacearum in greenhouse an field tests
Variety / Line Greenhouse test (Wilt index) Field test (Wilt infection)
Saturn 51.6 62.5
Venus 49.0 68.6
North carolina 1965-54 55.0 70.0
North carolina 1965-56 46.0 62.8
CRA.66 Selection A 5.0 8.0
HES. 5808 -2 43.0 100.0
Hawali 7626-6 100.0 91.0
Hawali 7742 92.8 96.4
Hawali 7746 93.7 100.0
Hawali 7747 100.0 98.0
Hawali 7748 94.1 100.0
Hawali 7759 85.0 89.3
Hawali 7761 100.0 76.0
Hawali 7763 91.6 70.0
Hawali 7723 83.3 91.6
511-7-3 76.5 73.7
530-4-3-6-3 85.0 66.6
531-7-1-bulk 83.3 80.0
537-4-1-7 100.0 79.1
556-5-5-5 70.0 85.5
557-5-1 bulk 68.0 67.5
557-5-1-30 100.0 80.7
Ceylon 60—8 63.0 72.6
Pusa Ruby 100.0 100.0
IIHR, Banglore Rao et al. (1975)
40. 40
Table 16: Disease reaction of tomato genotypes screened for bacterial wilt
No. Genotype Source Wilt % Disease reaction
1. Sakthi KAU, Kellanikkara 10 R
2. Mukti KAU, Kellanikkara 12 R
3. Le-474 GCRE Center, Florida 20 R
4. Le-415 Heinaz , USA 32.5 MR
5. Le- 470 KAU, Kellanikkara 22.5 MR
6. Le-214 AVRDC, Taiwan 22.5 MR
7. Le- 421 Portblair 25 MR
8. Le- 457 AVRDC, Taiwan 50 MS
9. BT-1 OUAT, Bhubaneshwer 52.5 MS
10. Le- 455 KAU, Kellanikkara 57.5 MS
11. Le- 526 NBPGR, New Delhi 80 S
12. Le-619 AVRDC, Taiwan 100 S
13. Le- 615 AVRDC, Taiwan 90 S
14. Le- 616 AVRDC, Taiwan 95 S
15. Le- 617 AVRDC, Taiwan 95 S
16. Le- 613 AVRDC, Taiwan 95 S
17. Le- 614 AVRDC, Taiwan 97.5 S
18. Le-618 AVRDC, Taiwan 100 S
19. BT- 101-22 OUAT, Bhubaneshwer 82.5 S
20. CO- 1 TANU, Coimbatore 70 S
21. CO- 3 TANU, Coimbatore 95 S
22. Pant- T1 GBPUAT, Pantnagar 100 S
23. Pant- T3 GBPUAT, Pantnagar 100 S
24. Pusa Ruby IARI,New Delhi 100 S
Bose et al. (2000)
43. 43
Table 18: Bacterial wilt resistance source of 20 tomato genotypes used in screening tests.
No. Genotype Location or institution Source of resistance
1. Capitan Pesto seed Co CRA 66
2. Caraibo INRA, West Indies CRA 66
3. CL 5915-93 AVRDC, Taiwan ?
4. CL 5915-153 AVRDC, Taiwan ?
5. CRA 66 INRA, West Indies West Indies ecotype
6. FMX 192 Ferry Morse Seed Co. ?
7. GA 219 Univ. of Georgia PI 126408 (Lycopersicon Esculentum)
8. GA1095 Univ. of Georgia PI 196298 (L. Esculentum)
9. GA 1405 Univ. of Georgia PI 251323 (L pmpinellifolium)
10. GA 1565 Univ. of Georgia PI 263722 (L. Esculentum)
11. Hawaii 7997 Univ. of Hawaii PI 127805A (L pmpinellifolium)
12. Hawaii 7998 Univ. of Hawaii PI 127805A (L pmpinellifolium)
13. Island red Yates Brothers, Trinidad ?
14. IHR 66 ICAR, India ?
15. PI 126408 Univ. of Florida L. Esculentum
16. Tomatillo Rogers NK Seed Co. Physalis ixocarpa
17. Venus North Carolina State Univ. and Beltsville 3841
(Lesculentum)
PI 129080 (L. Esculentum var
cerasiforme)
18. XPH 5675 Asgrow Seed Co ?
19. XPH 5677 Asgrow Seed Co ?
20 84 BWR ICAR, India ?
Florida, U.S.A. Chellami et al. (1994)
44. 44
Table 19: Bacterial wilt incidence for selected tomato cultigens
grown in a bacterial wilt infested field
No. Genotype Disease Incidence (%)
1. Hawaii 7997 0.0 b1
2. CRA 66 0.0 b
3. Ga.219 0.0 b
4. Ga.1565 2.5 b
5. Caravel 13.1 b
6. Capitan 20.0 b
7. Neptune 22.5 b
8. Calinago 39.3 ab
9. Solar Set 70.3 a
1 Mean separation by Duncan’s Multiple Range Test at <0.05.
Florida,U.S.A. Scott et.al. (1995)
45. 45
Table 20: Characteristics of the 36 entries in an international set of resistance sources to
bacterial wilt in tomato.
Entry Plant
Type1
Fruit size (g) BW resistance
source2
Seed Source
H7996 SD 30-80 PI 127805A J.W. Scott, University of Florida, USA
H7997S SD 30-80 PI 127805A “
H7998S ID 30 PI 127805A “
H7998M ID 30 PI 127805A “
CRA66S ID 30-40 CRA66 “
GA1565 ID 50-70 PI 263722 “
GA1405 SD 5 PI 251323 “
FLA7421 D 180 H7997 “
BRS – 1 D 100-200 Rodade J.A. Barnes, Queensland Department of Primary Industry, Australia
Rodade SD 100-150 BW2 “
Redlander SD 100-180 VC9-1 “
H7998M ID 30 PI 127805A S. Monma, Nat. Res. Inst. Of Veg., Ornam. Pl. & Tea (NIVOT), Japan
BF Okitsu ID 15-20 NC 19/53-64N “
TBL – 1 ID 150-200 King Kong “
TBL – 2 ID 200-250 King Kong “
TBL – 4 ID 200-250 King Kong “
TBL – 3 ID 150-200 King Kong “
MT – 1 D 50-60 ? T. Sadi, Malaysian Agric. Res. and Development Institute, Malaysia
MT – 11 SD 60-80 ? “
Intan Putih D 70 VC8-1-2-1 E. Puwati, Res. Institute of Vegetable, Indonesia
Taiwan Wang et al. (1998)
46. 46
Entry Plant
Type1
Fruit size
(g)
BW resistance
source2
Seed Source
Kemir ID 60-80 ? E. Puwati, Res. Institute of Vegetable, Indonesia
Ranti ID 20 ? “
TML 46 D 30 ? O.A. Licardo, University of Philippines at Los Baños, Philippines
TML 114 D 40 Venus, CA67(1169) “
R-3034 SD 30-60 ? “
F7- 80 pink D 25 ? “
H 7997 L SD 60-80 PI 127805A D. Linde, BHN Research, USA
CRA 66 P ID 30-40 CRA66 P. Prior, Inst. Nat. de la Rech. Agronomique (INRA), Guadeloupe
Caraibo SD 150 CRA66 “
Caravel D 150-300 CRA66 “
L 285 SD 30 L 285 Asian Vegetable Res. and Development Center (AVRDC), Taiwan
CLN 65 D 70 VC8-1-2-1 “
CLN 1463 ID 150-200 UPCA1169, Satum,
CRA84-26-3
“
CLN 1464 ID 160-180 UPCA1169, Satum,
CRA84-26-3
“
CL 5915 D 50 UPCA1169, Satum “
L 390 ID 40 Susceptible “
Cont….
1 D: determinant; ID: indeterminant; SD: semideterminant.
2 Bacterial wilt resistance source found in entry pedigreee. Bacterial wilt resistance of the following lines were derived from the following sources (in
parentheses) :
‘Kewalo’ (PI 127805A), ‘Venus’ and ‘Saturn’ (PI 129080) VC9-1(UPCA 1169) CRA84-26-3(CRA66)
King Kong (Kewalo) GA 1565(PI 263722) GA219 (PI 126408) GA1405 (PI 251323)
Taiwan Wang et al. (1998)
47. 47
Table 21: Bacterial wilt incidence for 11 tomato inbred 22 days after inoculation.
Inbred Healthy Plants (%)1
E 306 96.7 a2
E 305 93.3 ab
Hawaii 7997 90.0 ab
Fla. 7997 89.7 ab
E 304 83.3 abc
Fla. 8109 82.3 abc
E 307 76.7 bc
Fla. 8109B 75.3 bc
Caravel 58.7 cd
Neptune 34.3 d
Florida MH13 33.3 d
1 Rated 22 days after inoculation.
2 Mean separation by Duncan’s Multiple Range Test at <0.05 performed on data transformed to sq. arcsine.
3 Susceptible control.
Florida, U.S.A. Scott et al. (2003)
49. 49
1. Introduction
This is an easy and rapid method of developing bacterial wilt
resistant variety.
The resistant variety may be introduced and after testing if
found suitable, can be released in the disease prone area.
2. Selection
When the source of resistance is a cultivated variety;
mass selection and pure lines selection.
50. 50
3. Hybridization
Hybridization is used when resistant genes are available either
in the germplasm or in the wild species.
The pedigree method is used when the resistance is governed
by polygenes and the resistant variety is an adapted one which also
contributes some desirable agronomic traits.
The backcross method is used when the resistant parent is
unadapted type or the resistant gene is to be transferred from wild
species. It is more commonly used when the resistance is governed by
mono or oligogenes.
51. 51
Gene Pyramiding :
Incorporation of two or more major genes in the host
for specific resistance to bacterial wilt in a single
cultivar.
Provides broad spectrum and durable resistance.
52. 52
Fig. 8: Pedigree of ‘Rodade” Tomato
Pretoria, South Africa Bosch et al.(1985)
54. 54
Multiple Resistant
Neptune is resistant to,
1. Fusarium Wilt race 1 and 2 [Fusarium oxysporum Schlecht
f. sp. lycopersici (Sacc.) Snyder and Hansan]
2. Verticillium wilt race 1 and [Verticillium dahliae Kleb.]
3. Gray leaf spot [Stemphyllium solani Weber]
Florida Scott et al. (1995)
55. 55
Heterosis breeding:
Hybrids can be developed when resistance is governed
by a dominant gene or both the parental lines are
resistant with monogenic recessive inheritance.
56. 56
B. NON-CONVENTIONAL
Bose. (2000) identified PRX 7 (Rm=0.361) and PRX 8 (Rm=0.382)
in 45 days old leaf samples as isozyme marker for resistant and
moderately resistant varieties. PRX 5 (Rm=0.297) in 60 days old
leaf samples was very specific to resistant varieties.
57. 57
• Zymogram of peroxidase in tomato leaves at 45 days
• Zymogram of peroxidase in tomato leaves at 60 days
60. 60
Table 23: Origin and principle characteristic of tomato cultivars
No. Cultivars Origin Country Growth Status
1. Hawai 7996 Univ. Hawaii United States D R
2. CRA-66 INRA Antilles N R
3. CLN 657 AVRADC Taiwan N R
4. Caraibo INRA Antilles D R
5. FMTT 3 AVRADC Taiwan D R
6. CRA 90-30 INRA Antilles D R
7. Calinago INRA Antilles D R
8. Caracoli INRA Antilles N MR
9. PT- 4165 AVRADC Taiwan D MR
10. Floradel Petoseed .Co United States N S
Grimault et al. (1994)
61. 61
Table 24: Combining bacterial spot resistance from races T1 and T3 provides
T2 resistance.
1 Fla. 7835 T1 and T3 resistance was derived from Fla. 7600 and PI 126932.
Ohio Wooster (1995)
Genotype Race T2 Disease Severity Resistance
(Race)
1995 1996 1999 2000
Fla. 7600 - 5.3 a - - T1
PI 126932 5.3 a - - - T3
Solar Set 6.0 a 5.8 a 5.5 a 5.3 a (Susc.)
PI 114490 2.0 b 2.0 b 2.0 c 2.0 c T2
Fla. 78351 - - 3.3 b 3.3 b T1, T3
63. 63
Table 26: Percent survival for 9 entries in 12 countries in the world
Entry Location1 MEAN
JPN AVR TSS PLP NEP IND AUS MAR REU GDL FLA BRA
H 7996 100 85 100 97 100 87 100 96 100 97 100 100 97
BF-Okitsu 100 68 100 100 97 100 100 54 100 97 100 97 93
H 7997 S 64 80 100 93 98 100 90 86 100 94 100 100 93
TML 46 80 83 100 *90 100 90 95 88 93 84 96 100 92
H 7998 S 32 63 100 97 100 100 95 100 100 95 100 100 92
TML 114 35 77 100 100 100 98 100 88 100 95 83 100 91
R 3034 90 72 97 87 95 94 80 77 100 99 100 100 91
Neptune 0 0 44 60 67 3 50 2 32 42 96 73 43
L 390(Susc.) 0 0 0 7 0 0 0 2 6 37 56 23 13
Mean 2 34 40 87 81 87 73 73 52 83 68 84 77 71
WD LSD 23 19 15 26 20 20 26 33 56 26 27 23 12
1 JPN-Japan, AVR-Taiwan (AVRDC), TSS- Taiwan, PLP-Philippines, NEP-Nepal, IND-India, AUS-Australia,
MAR-Mauritius, REU-Reunion, GDL-Guadeloup, FLA-Florida,U.S.A. BRA-Brazil.
2Mean of all entries in the trial.
Taiwan Wang et al. (1998)
64. 64
Table 27: Reaction of bacterial wilt resistant accessions of tomato to
Ralstonia solanacearum over 2 years
No. Genotype Wilt incidence (%) Type of reaction
1. HAWAII 7998 3.13 (7.68) Highly resistant
2. EC 191536 9.02 (17.39) Highly resistant
3. CRA- 66 9.67 (18.11) Highly resistant
4. BWR 5 13.17 (19.59) Resistant
5. TML 1146 48 –NT5 11.67 (19.93) Resistant
6. BL 342-1 13.17 (21.04) Resistant
7. TBL 4 18.54 (24.32) Resistant
8. BL 333 19.79 (26.41) Resistant
9. BT 18 21.13 (27.34) Moderately resistant
10. BRH 2 27.42 (31.49) Moderately resistant
11. Solan Gola 94.79 (77.01) Highly susceptible
12. Roma 95.84 (78.43) Highly susceptible
Cd (P = 0.05) (17.92)
Bajaura, Himachal Pradesh Sharma et al. (2002)
65. 65
Table 28: Bacterial Wilt Tolerant Hybrids
No. Hybrid Habit Fruit Weight
(gm)
Characteristics
1. Swaraksha Determinate 75-80 Highly tolerant to bacterial wilt, suitable
for fresh market.
2. Amar Determinate 75-80 Tall robust plant, high yielder
3. BWT 1 Determinate 75-80 Very early, excellent color and firmness
4. NS 52 Determinate 80-85 Large fruits
5. NS 53 Determinate 80-85 Excellent smoothness, good tolerance to
BW
6. NS 4572 Determinate 80-85 Prolific bearing
7. VT 1 Indeterminate 90-100 Early, short indeterminate, attractive
clusters
8. VT 4 Indeterminate 90-100 Good firmness
India Namdhariseeds
66. 66
LIMITATIONS
Race specific resistance
Resistance is temperature dependent
Lack of prompt and effective screening techniques
Polygenic inheritance of resistance
Poor interdisciplinary approach
Lack of nation-wide network for resistance breeding
67. 67
CONCLUSION
1. Among all races of Ralstonia solanacearum, Race 1 and Race 3
cause heavy crop losses in Tomato.
2. The cheapest method for management of bacterial wilt is
through developing resistant cultivars.
3. The effectiveness of resistance breeding programme is
dependent on the availability of efficient screening procedures,
identification of adequate source of durable resistance and
knowledge of inheritance of resistance.
4. Identifying germplasm lines harboring genes for bacterial wilt
resistance and incorporating them in cultivated species through
conventional and non conventional methods are of prime
importance for achieving success in breeding for bacterial wilt
resistance
68. 68
Future thrusts
Development of reliable, rapid and efficient screening method
for resistance.
There is need to develop multiple resistant cultivars for
bacterial wilt and other diseases and insects through
combination of new molecular tools with conventional
breeding methodology.
Multidisciplinary approaches will help in developing multiple
resistant cultivars.
Monitoring of new races/strains required
