Here, I have described about vegetable grafting and it's application in plant breeding. In this prescription, I have mentioned about history, methods, practical application to fight against biotic and abiotic stresses, various important rootstocks, several case studies and achievements related to vegetable grafting. This presentation will be useful for horticulturists who study olericulture as well as plant breeders.

1. 1

2. VEGETABLE GRAFTING: A NEW CROP
IMPROVEMENT APPROACH
Speaker
Suthar Himul Jayeshbhai
Reg. No. 2010122065
M. Sc. (Agri.)
Dept. of Genetics and Plant Breeding
College of Agriculture
JAU, Junagadh
Major Guide
Dr. V. H. Kachhadia
Associate Research Scientist
Vegetable Research Station
JAU, Junagadh
Minor Guide
Dr. H. P. Gajera
Professor & Head
Dept. of Molecular Biology & Biotechnology
JAU, Junagadh
2

3. C O N T E N T S
Introduction
Grafting
Rootstock
Breeding methods
Important rootstocks
Case studies
Conclusion
3

4. INTRODUCTION
4

5. INTRODUCTION
 The fresh and edible portions of
herbaceous plants are termed as
vegetables, which are important
component of a healthy diet
 2021 : “International Year of Fruit
and Vegetables”
 Vegetables are the important source
of vitamins and minerals, dietary
fibers and antioxidants
5

6. Source: Anon., 2021
Table 1: Vegetable production in India 2021-22
Sr.
No.
States Area (‘000 ha)
Production (‘000
Tonnes)
1. Bihar 904.6 17,855.4
2. Gujarat 832.4 16,614.8
3. MP 1,161.4 22,206.3
4. Maharashtra 1,192.5 17,189.5
5. Odisha 658.1 9,280.5
6. UP 1,350.4 32,505.1
7. West Bengal 1,532.8 28,450.1
India 11,374.4 209,143.4
6

7.  Per capita consumption of vegetables in India is only about 180
g/day/person though the vegetable requirement is 300g/day/person
 Vegetable production is hindered by biotic (Insect-pests) and abiotic
(environmental & soil stress) factors.
 Among all management tactics, vegetable grafting is considered as eco-
friendly for sustainable vegetable production as a result of the resistant
rootstock reduces the dependency upon agrochemicals for control soil
borne pest (Root knot nematode) and disease (Fusarium wilt, Bacterial
wilt, Root rot, etc).
7

8.  The method of joining parts of two
different plants in a manner that they
form a unit and function as one plant is
known as ‘grafting’
 Grafting : ‘PHYSICAL HYBRIDS’
 Scion : Produce fruit
 Rootstock : Provide important traits
 Plants propagated by grafting are true-
to-type.
GRAFTING
8

9. HISTORY
 During 5th century in China, self grafting was used as a
technique to produce large sized gourd fruits.
 Commercial grafting in vegetables originated in early 20th
century with aim to manage soil borne pathogens.
 However, scientific vegetable grafting was first launched in
Japan and Korea in late 1920s to avoid soil borne diseases.
 Scientific studies investigating and developing rootstocks was
initiated in the 1960s in Korea.
Bie et al., 2017
9

10. LANDMARKS IN VEGETABLE GRAFTING
10

11. GENETIC BASIS OF VEGETABLE GRAFTING
• In grafted plant, it is found that genetic information is being traded
between grafting partners.
• Exchange of genetic material between stock and scion takes place in
the form of small RNA molecules, these molecules transported via
phloem tissue.
• In grafted plants, epigenetic modifications such as alterations in
DNA methylation level is also observed.
Majhi et al., 2023
11

12. GRAFTING IN
VEGETABLE
CROPS
12

13. 1. Cleft
grafting
2. Tongue
approach
grafting
3. Tube
grafting
4. Hole
insertion
grafting
5. Slant
grafting
6. Pin
grafting
13

14.  The rootstock stem is cut horizontally
and 0.5 cm long vertical incision is
created into the middle of the
rootstock.
 The scion stem is cut into a 0.5 cm
long wedge and is inserted into the
vertical incision in the rootstock and
the joint is secured by the help of
grafting clips
 Generally solanaceous crops are
grafted by conventional cleft grafting
CLEFT GRAFTING
14
14

15.  The matching 45° incisions are made
in both scion and rootstock stems, to
form “tongues”
 The both stem tongues are joined
together in order that the cut surfaces
are in contact
 After fully healing, the rootstock top
and the scion roots are cut off from the
grafted plant
 This method is not utilized in
rootstocks with hollow hypocotyls
TONGUE APPROACH GRAFTING
15

16.  Cut rootstock beneath cotyledons in a 45°
or sharper angle
 Prepare the scion with matching
hypocotyl width cut in the same angle at
5-10 mm below the cotyledons
 Stock and scion should have equal
diameter
 Place one tube a halfway down on top of
the cut end of rootstock hypocotyl
 Insert the scion into the grafting tube in
order that cut surface aligns perfectly
with that of rootstock
TUBE GRAFTING
16

17.  When scion and rootstock
have hollow hypocotyls, this
methodology is preferred
 A hole in the rootstock is
created for insertion of the
scion
 The scion is then inserted in
the hole in the rootstock and
the joint is secured by the help
of grafting clips
HOLE INSERTION GRAFTING
17

18.  Recently, it has been adopted
by commercial seedling
nurseries because it is
applicable to most vegetable
crops and mainly developed
for robotic grafting
 Grafting can be done by
creating slant cuts on both
rootstock and scion by
retaining only one cotyledon
leaf on the rootstock
SLANT/SPLICE GRAFTING
18

19. PIN GRAFTING
 In this method, instead of grafting clips, specially designed pins are
used to hold the graft position
 The size of the ceramic pin is nearly about 15 mm long and 0.5 mm
in diagonal width of the hexagonal cross-section
 The pins are made from natural ceramic; therefore, it can be left on
the plant without any problem. Bamboo stick can also be used
19

20. MECHANIZED GRAFTING
 First semi automatic cucumber
grafting system was
commercialized in 1993
 A semi automatic grafting
machine can produce 400–600
grafts/hour, whereas manual
grafting techniques produce about
1,000 grafts/ person/day
 A fully automated grafting robot
produce 700 grafts/hours with 90-
93% success rate
20

21. Root stocks
Scions
Compatibility
Grafting aids
Screen house
Healing chamber
Acclimatization chamber
PREREQUISITES OF GRAFTING
21

22. 22
Grafting Clips Grafting Blade Grafting Tubes
Screen
House
Healing
Chamber
22

23. Best time to graft
Source:-http://dx.doi.org/10.1080/19315260.2017.1357062
23

24. S T E P S
O F
G R A F T I N G
2
3
4
5
7
6
1 Select scions and rootstocks
Schedule the best time to graft
Make the grafts
Plant the seeds
Monitor the healing process
Acclimate the healed grafts
Plant grafted plants
24

25. GRAFTING TIMELINE
Rosskopf et al., 2018
25

26. 26
ROOTSTOCK

27.  The part of the graft that provides root
system to the grafted plant is known as
‘rootstock’
 Rootstock is the base and root portion
of a grafted plant
 Any compatible wild spp. / resistant
variety / resistant hybrid can be used as
rootstock
27
ROOTSTOCK

28. IDEAL ROOTSTOCK
 It must have good compatibility with the scion
 It should give maximum economic life to the plant
 It should be well adaptable to the agro climatic conditions
 It must have resistance against biotic stress like soil borne pests and
disease
 It should have tolerance to drought, salt and frost
 It must have a positive impact on the scion's performance
28

29. BIOTIC STRESS
 Biotic stresses are negative influences caused by other living
organisms
 In agriculture, biotic stress is a major cause of pre and post harvest
losses
 Biotic stress agents directly deprive their host for its nutrients,
leading to reduce plant vigor and in extreme cases, death of the host
plant
 The intensity of biotic stress varies depending on the weather,
cropping system, cultivation practices, type of crops, crop varieties,
and their resistance levels
29

30. LOSSES IN VEGETABLES DUE TO BIOTIC STRESS
Source: NIBSM, 2020
40%
30

31. ABIOTIC STRESS
 Abiotic stress cause considerable losses in vegetable crops
across the globe
 An estimated loss in average yield of major crops due to abiotic
stresses is around 50%
 Due to global warming and ongoing climate change, impact of
these stresses are going to be increase across the globe
 Impact of abiotic stress can vary depending on the genotype,
growth stage of plant, intensity and duration of stress.
31

32. Abiotic
stress
Metal
toxicity
Flood
Drought
Salinity
Thermal
stress
LOSSES IN VEGETABLES DUE TO ABIOTIC STRESS
Source: Khapte et al., 2019
32

33. Resistance
to Biotic
Stress
Resistance
to Abiotic
Stress
Reduced
chemical
application
Wide
Geographical
adaptability
Improve
quality
traits
Adaptation
in different
soil type
33

34. 34
Breeding
methods for
rootstock
improvement

35. BREEDING APPROACHES FOR
ROOTSTOCK IMPROVEMENT
Conventional Methods
•Selection
•Hybridization
o Intra-specific hybridization
o Interspecific hybridization
o Intergeneric hybridization
Non-Conventional Methods
•Somatic hybridization
•Transgenic breeding
Dhoot et al., 2017
35

36. Thompson et al., 2017
36

37. Important
Rootstocks
37

38. IMPORTANT TOMATO ROOTSTOCK
Species Specific features
Solanum pennelli Tolerance to drought
S. galapagense Tolarant to salt
S. habrochaites Resistance to cold and diseases (TMV)
S. chilense Resistance to drought and diseases
S. Neorickii Resistant to bacterial diseases
S. Pimpinellifolium Colour, quality, resistance to disease
S. lycopersicum var.
cerasiforme
Tolerance to humidity, resistance to fungi and root
rot
S. peruvianum Resistance to tomato spotted wilt virus and RKN
Source http://www.vegetablegrafting.org/
38

39. Species Specific features
S. macrocarpon & S. gilo Tolerant to drought
S. torvum
Tolerant to flooding, heavy metal
Resistance to Verticillium wilt, Fusarium wilt
S. xanthocarpum Resistance to phomopsis blight
S. sisymbrifolium Resistant to little leaf
S. auriculatum Resistant to little leaf disease
S. indicum Resistant to RKN
IMPORTANT BRINJAL ROOTSTOCK
Source http://www.vegetablegrafting.org/
39

40. Rootstock (species) Specific features
Bottle gourd (Lagenaria siceraria) VRS, FT, LTT
Squash (Cucurbita moschata Duch.) VRS, FT, LTT
Interspecific hybrid squash (Cucurbita maxima Duch. ×
C. moschata Duch.)
VRS, FT, LTT
Pumpkins (Cucurbita pepo L.) VRS, FT, HTT
Wintermelon (Benincasa hispida Thunb.) GDR
African horned (AH) cucumber (Cucumis metuliferus ) FT, NMT
IMPORTANT WATERMELON ROOTSTOCK
VRS: Vigorous Root Systems
FT: Fusarium Tolerance
LTT: Low Temperature Tolerance
NMT: Nematode Tolerance
HTT: High Temperature Tolerance
GDR: Good Disease Resistance
Dhall et al., 2016
40

41. Crop Rootstock (species) Resistance
Cucumber
Fig leaf gourd (Cucurbita ficifolia Bouché) LTT, GDT
Squash (Cucurbita moschata Duch.) FT, GDT
Interspecific hybrid squash (Cucurbita maxima
Duch. × C. moschata Duch.)
FT, LTT
Bur cucumber (Sicyos angulatus L.) FT, LTT, SMT, NMT
Muskmelon
Squash (Cucurbita moschata Duch.) FT, LTT
Interspecific hybrid squash (Cucurbita maxima
Duch. × C. moschata Duch.)
FT, HTT, SMT
Pumpkin (Cucurbita pepo L.) FT, HTT, SMT
IMPORTANT CUCURBITS ROOTSTOCK
GDT: Good Disease Tolerance
SMT: High Soil Moisture Tolerance Dhall et al., 2016
41

42. Crop
name
Bacterial
wilt
Fusarium
wilt
Pythium Root-
knot
nematode
Flooding Salinity
Tomato VI043614
(Hawaii 7996)
VI043614 VI006378 - VI0006378
Egg
plant
GE195 VI046104 VI046104 VI046103 VI041752
TS03
EG219
EG190
RECOMMENDED ROOTSTOCK BY WORLD
VEGETABLE CENTRE
Source: https://avrdc.org/seed/improved-lines/rootstock/
42

43. CASE
STUDIES
43
43

44. 1
GRAFTING TOMATO FOR SUSTAINABLE
MANAGEMENT AGAINST Fusarium WILT
Objective:
 To assess disease severity of Fusarium wilt on grafted tomato
 To evaluate yield performance of grafted tomato against
Fusarium wilt
Awu et al., 2023
Greater Accra, Ghana 44

45. Materials and Methods:
 Two Solanum species S. macrocarpon and S. torvum used as
rootstock and S. lycopersicum variety Petomech was selected as
scion.
 Grafting was done by cleft method of grafting.
 The experiment was conducted in pots at University of Ghana
with CRD design with three replications.
45
S. torvum S. macrocarpon

46. Figure 1: Disease severity of grafted and non-grafted plants at 2, 3, 4, 5
and 6 weeks after inoculation with F. oxysporum
46

47. Rootstocks Fruit Yield/plant (g) No. of fruits/plant
Non-grafted 205.1 ± 25.2 a 7 ± 1.21 a
S. macrocarpon 453.1 ± 10.6 c 5 ± 1.38 a
S. torvum 350.3 ± 18.5 b 7 ± 0.85 a
Table 2: Yield performance of grafted and non-grafted tomato in pots
infected with F. oxysporum
47
Values followed by different lowercase letter(s) within a column are significantly different at 5% probability level.

48. 2
EVALUATION OF BACTERIAL WILT
RESISTANCE OF WILD Solanum SPECIES
THROUGH GRAFTING IN BRINJAL
Objective:
 Evaluation of wild Solanum species against bacterial wilt
 To identify best grafting combination of eggplant for resistance
against bacterial wilt
Kumar et al., 2017
CAU, Pasighat
48

49. Materials and Methods:
 A total of four wild Solanum species as rootstocks and two eggplant
genotypes as scion were included in the experiment.
 Plants were grafted by cleft method of grafting.
 The experiment was laid out in nursery with CRD design with four
replications.
Species Eggplant genotypes
Solanum torvum Pusa Shyamala
Solanum xanthocarpum Pusa Hybrid-6
Solanum khasianum
Solanum surathense
49

50. S. xanthocarpum S. khasianum
S. surathense
50

51. Wild Solanum species and
eggplant genotypes
% Wilt infection Grading
Solanum torvum 5.768 Resistant
Solanum khasianum 15.825 Moderately resistant
Solanum xanthocarpum 46.125 Susceptible
Solanum surathense 54.475 Susceptible
Pusa Shyamala 72.175 Susceptible
Pusa Hybrid-6 68.375 Susceptible
Table 3: Response of wild Solanum species and eggplant genotypes
against bacterial wilt
51

52. Table 4: Effect of different wild Solanum species in percent bacterial
wilt infection of grafted plants
Grafting combinations % Wilt infection Grading
S. torvum×Pusa Shyamala 12.225 Resistant
S. xanthocarpum×Pusa Shyamala 45.500 Susceptible
S. khasianum×Pusa Shyamala 29.600 Moderately Resistant
S. surathense×Pusa Shyamala 58.525 Susceptible
S. torvum×Pusa Hybrid-6 13.475 Resistant
S. xanthocarpum×Pusa Hybrid-6 48.175 Susceptible
S. khasianum×Pusa Hybrid-6 31.475 Moderately Resistant
S. surathense×Pusa Hybrid-6 55.300 Susceptible
Control 71.350 Susceptible
52

53. 3
GRAFTING OF TOMATO ONTO SALT
TOLERANT EGGPLANT ROOTSTOCKS TO
IMPROVE YIELD PERFORMANCE UNDER
SALINE CONDITIONS
Objective:
 To evaluate Effect of salinity and rootstock combinations on
yield performance of tomato by using salt tolerant eggplant
cultivars as a rootstocks
Sanwal et al., 2022
53

54. Materials and methods:
 Two eggplant cultivar IC-354557 and IC-111056 used as a rootstocks
and tomato variety Kashi Aman was used as scion.
 Splice method of grafting was used.
 Experiment was conducted as per RBD with five replications.
 Experiment was carried out during winter season in 2017 and 2018.
 Three different irrigation water treatments were given:
1. EC~1 dsm-1(control)
2. EC=6 dsm-1
3. EC=9 dsm-1
54

55. Table 5: Effect of salinity and rootstock combinations on yield performance
of tomato (Kashi Aman) in 2017
Salinity treatment Rootstock Fruit yield (g/plant) Avg. fruit weight (g)
Control Non-grafted 2577.3 a 64.45 a
IC-111056 2518.0 a 63.12 a
IC-354557 2388.0 b 63.83 a
EC 6 dsm-1
Non-grafted 1420.8 b 56.10 b
IC-111056 1871.3 a 59.23 a
IC-354557 1800.4 a 60.22 a
EC 9 dsm-1
Non-grafted 522.8 c 41.37 b
IC-111056 1265.3 a 48.63 a
IC-354557 1053.4 b 47.62 a
55
Values followed by different lowercase letter(s) within a coloum are significantly different at 5% probability level.

56. Table 6: Effect of salinity and rootstock combinations on yield performance
of tomato (Kashi Aman) in 2018
Salinity treatment Rootstock Fruit yield (g/plant) Avg. fruit weight (g)
Control Non-grafted 2243.10 b 60.15 b
IC-111056 2301.87 a 61.87 a
IC-354557 2227.15 b 62.05 a
EC 6 dsm-1
Non-grafted 1340.77 c 54.30 a
IC-111056 1781.70 a 55.82 a
IC-354557 1664.05 b 54.53 a
EC 9 dsm-1
Non-grafted 532.18 c 39.00 c
IC-111056 1132.25 a 46.53 a
IC-354557 1019.10 b 43.52 b
56
Values followed by different lowercase letter(s) within a coloum are significantly different at 5% probability level.

57. 4
EVALUATION OF DIFFERENT BACTERIAL
WILT RESISTANT EGGPLANT
ROOTSTOCKS FOR GRAFTING TOMATO
Objective:
 To evaluate the Bacterial Wilt resistance, as well as the
agronomical potential and the efficiency of the newly identified
eggplant accessions in the field as rootstocks for tomato grafting
Materials and Methods:
 Five eggplant accessions were identified as bacterial wilt resistant
by screening and subsequently the accessions were purified and bulked
up through single-seed descent method at Worldveg.
Manickam et al., 2021
Tainan, Taiwan
57

58. Continue..
 Bacterial wilt resistant eggplant accessions (VI041809A,
VI041943, VI041945, VI041979A, and VI041984) were
evaluated as rootstocks and two different fresh market tomato
cultivars (Victoria and TStarE) were used as scion.
 The tube grafting method was used for grafting.
 Experiment was carried out as per RBD with four replications.
Rootstockc Species Origin
VI041809A
Solanum melongena India
VI041943
VI041945
VI041979A
VI041984 58

59. Accession
Compatibility (%) Wilting (%) Disease Index (%)
Survival
(Out of 12 plants)
2018 2019 2018 2019 2018 2019 2018 2019
VI041809A 100 a 100 2.1 c 10.4 c 2.1 b 10.4 b 11.8 a 9.5 a
VI041943 100 a 100 0.0 c 5.8 c 0.0 b 8.3 b 12.0 a 10.8 a
VI041945 93 b 100 0.0 c 14.6 c 0.0 b 16.7 b 12.0 a 5.5 abc
VI041979A 96 ab 100 2.1 c 7.9 c 0.8 b 10.4 b 12.0 a 9.0 ab
VI041984 99 ab 100 2.1 c 20.0 c 2.1 b 20.8 b 11.8 a 8.8 ab
VI045276 (R-Check) 94 ab 100 4.2 c 7.5 c 4.2 b 8.3 b 11.5 a 8.5 ab
VI046095 (S-Check) 99 ab 100 100.0 a 87.5 a 100.0 a 91.7 a 0.0 c 0.0 c
Self-Grafted 100 ab 100 50.0 b 100.0 a 43.8 a 100.0 a 7.0 b 2.0 c
Non-Grafted - - 72.9 b 97.5 a 63.3 a 100.0 a 5.0 b 2.3 bc
Table 7: Graft compatibility of different rootstocks and effect of rootstock
accession on wilting %, BW disease index (DI) and field survival of
grafted plants
59
Values followed by different lowercase letter(s) within a coloum are significantly different at 5% probability level.

60. Table 8: Total yield (kg/plot) of grafted and non-grafted plants
60
60
Accession 2018 2019
VI041809A 26.29 ± 5.37 ab 0.71 ± 0.71
VI041943 29.36 ± 5.24 a 1.27 ± 0.87
VI041945 17.61 ± 2.9 bc 1.01 ± 0.48
VI041979A 32.49 ± 4.1 a 0.65 ± 0.33
VI041984 17.66 ± 2.43 bc 0.92 ± 0.58
VI045276 (R-Check) 24.33 ± 4.04 abc 0.83 ± 0.52
VI046095 (S-Check) 0.0 ± 0.00 d 0.29 ± 0.58
Self-grafted 17.49 ± 7.77 bc 0.00 ± 00
non-grafted 15.44 ± 4.69 c 0.07 ± 0.13
Values followed by different lowercase letter(s) within a coloum are significantly different at 5% probability level.

61. 5
EVALUATION OF YIELD PERFORMANCE OF
GRAFTED SEEDLINGS OF PEPPER UNDER
COMMON OPEN FIELD CONDITIONS
Objective:
 To study impact of grafting on yield performance of pepper
under common open field conditions
Materials and methods:
 Pepper cultivar Somborka grafted onto rootstock Rokal, Fortama
F1 and non grafted plants were used in experiment.
 Plants were grafted by tube method of grafting.
 Experiment was carried out as per RBD with three replications.
Rizani et al., 2022
Prishtina, Kosovo
61

62. Rootstock
Yield
(kg/plant)
No. of
fruits/plant
Fruit weight
in gram
Non-grafted 4.32 b 52.00 b 83.10 b
Rokal 5.04 a 57.00 a 88.33 a
Fortama F1 5.16 a 59.00 a 87.46 a
Table 9: Effect of rootstock on yield performance in pepper under
common open field conditions
62
Values followed by different lowercase letter(s) within a coloum are significantly different at 5% probability level.

63. ADVANTAGES
63 Majhi et al., 2023

64. DISADVANTAGES
Labour intensive
if done manually
Costlier when
done by
automatic
robotic way
Quality of fruit
may be down by
improper
combination
Grafting
incompatibility
High cost of
grafted seedlings
64
Majhi et al., 2023

65. 65
ACHIEVEMENTS
 Grafting in Solanaceous and Cucurbitaceous crops is popular,
protocols for grafting and desired rootstock accessions have been
identified for these crops.
 In India, at IIVR, Varanasi, UP field demonstration of grafted
‘Pomato’ (potato+tomato) and ‘Brimato’ (brinjal+tomato) was
conducted during 2020-21.
 CSKHPKV-Palampur is the 1st agricultural university in the
country to install semi-automatic ‘Grafting Robot’ in July,2017.

66. 66
CONCLUSION

67. 67
CONCLUSION
Grafting vegetable onto resistant rootstocks is an innovative strategy
to grow susceptible scion to give enhanced economic return even in the
presence of biotic and abiotic stresses. Grafting dispenses opportunities to
exploit natural genetic variation for particular root traits to alter the
phenotype of the shoot as per the demand. Manipulation of the scion
morphology and physiology, management of the soil borne pathogens can
be done by the use of suitable rootstock and scion combination. It has also
emerged as an environment-friendly and climate resilient approach.

68. 68 68

69. 69