Remzeena, A
Influence of rootstocks on yield, quality and bacterial wilt resistance in F1 hybrids of Tomato - Vellanikkara Department of Vegetable Science, College of Agriculture 2024 - 167,xxxi,xiip.
Ph.D
Tomato production in the tropics and subtropics is often hampered by the incidence
of various pests and diseases. Among these, bacterial wilt caused by the soil-borne bacteria
Ralstonia solanacearum poses a significant problem for tomato growers in Kerala. The
warm, humid, tropical climate and acidic soil conditions prevailing in the state provide a
favorable environment for wide spread occurrence of bacterial wilt in the state. Growing
resistant varieties have been identified as one of the most effective management strategy.
However, the development of bacterial wilt-resistant varieties or hybrids is challenging due
to the quantitative nature of the trait, its linkage to small fruit size, and the diversity of
pathogen strains. Therefore, an effective alternative is grafting tomato cultivars having high
production potential onto bacterial wilt resistant rootstocks. In addition to providing
complete resistance to bacterial wilt, grafting also helps in harnessing improved yield. In
this context, the present study was undertaken with the objectives of identifying bacterial
wilt-resistant rootstocks for tomatoes, evaluating the performance of the grafts for yield,
quality, and bacterial wilt resistance, and determining their suitability for growing in the
rainshelter.
In experiment 1, ten F1 hybrids of tomato were collected and evaluated in sterilized
medium for their yield and quality. Hybrids exhibited significant variation for yield and
quality traits. Among the hybrids significantly high plant height was exhibited by Arka
Apeksha. Days to flowering and harvest was minimum in Lakshmi. Arka Rakshak
exhibited highest root length and spread followed by Arka Apeksha. Average fruit weight
was significantly high in Arka Abhed (97.56g) followed by Arka Samrat (89.68g). Lakshmi
recorded significantly highest fruit yield per plant (3.28 kg) which was on par with Arka
Samrat (2.86 kg) and Arka Abhed (2.78 kg) followed by Arka Rakshak (2.65 kg),
Sampurna (2.62 kg) and Arka Apeksha (2.59 kg). Fruit quality traits such as lycopene,
vitamin C, TSS was the highest in Arka Apeksha. Sampurna recorded the highest acidity
and total phenol was the highest in COTH3. NSC 620B recorded the highest
Orthodihydroxy (OD) phenol and the lowest solasodine content was recorded in Arka
Apeksha.
Among the hybrids the highest bacterial incidence was recorded in Shivam (72.50 %) and
the hybrid Arka Abhed recorded zero per cent incidence. Tomato Leaf Curl Virus (ToLCV)
incidence was highest in COTH3 whereas, six hybrids Lakshmi, Sampurna, Arka Rakshak,
Arka Abhed, Arka Samrat and Arka Apeksha was completely free from ToLCV incidence.
In the experiment 2, six high yielding tomato hybrids from the experiment
1 (Lakshmi, Arka Samrat, Arka Abhed, Arka Rakshak, Sampurna and Arka Apeksha) were
grafted on four brinjal rootstocks viz., Surya, Haritha, SM 3, SM 116 and two Solanum
torvum rootstocks (KAU-1and TNAU-1). These grafts were evaluated for their yield,
quality and bacterial wilt resistance in bacterial wilt sick field. Plant height, girth of graft
(60 DAP), root length and spread, average fruit weight were significantly improved in the
grafted plants compared to their non-grafted controls. The highest plant height was
recorded in the grafts on SM 116 and Haritha and the lowest plant height was recorded on
SM 3 irrespective of the scion. Girth of graft was significantly high when grafted on Haritha
in all the hybrids which was followed by the grafts on Surya. Root length and spread were
also significantly high in grafts on Haritha followed by the grafts on Solanum torvum
rootstocks. Grafts on Haritha recorded the highest overall average fruit weight which was
on par with the grafts on Surya. Days to flowering and days to harvest were delayed in the
grafted plants compared to the non-grafted controls. However, significant improvement
was recorded in the crop duration of grafted plants compared to non-grafts. Fruit yield was
significantly improved compared to non-graft control on Haritha, Surya and SM 116 in all
the hybrids. Arka Rakshak (4.17 kg) , Lakshmi (3.98 kg), Arka Samrat (3.85 kg), Arka
Abhed (3.83 kg) and Arka Apeksha (3.76 kg) exhibited highest fruit yield per plant on
Haritha, whereas, Sampurna showed the highest fruit yield per plant on Surya (3.75 kg).
Among the 36 graft combinations, Arka Rakshak, Lakshmi, Arka Samrat, Arka Abhed,
Arka Apeksha grafted on Haritha and Arka Rakshak, Sampurna, Lakshmi on Surya
recorded the highest yield per plant and performed on par with each other.
Total Soluble Solids (TSS) of the fruits of grafted plants were on par with that of
non-grafted control in all hybrids. Acidity increased in the fruits of grafts compared to the
non-grafts. Lycopene content of the grafts were on par with non-grafted control except in
the grafts of Sampurna on Haritha and Solanum torvum rootstocks. Fruits of grafted plants
also recorded a decrease in vitamin C compared to non-grafted control. However, vitamin
C content of fruits of grafts on Haritha and Surya were on par with that of the non-grafted
control in all the hybrids except Lakshmi. Total Phenol, OD Phenol and Solasodine content
increased significantly in grafted plants compared to non-grafted control. Sensory
evaluation of fruits of grafted and non-grafted plants indicated only non-significant
difference between grafts and non-grafted control. Overall acceptability was similar or
higher in grafts compared to non-grafts except in the grafts of Lakshmi and Sampurna on
Solanum torvum rootstocks.
Grafts on the brinjal rootstocks Surya, Haritha, SM3 and SM 116 recorded zero
percent incidence of bacterial wilt. Whereas grafts on Solanum torvum rootstocks (TNAU-
1 and KAU- 1) recorded 6.67-13.33 per cent incidence. Rootstocks did not influenced the
ToLCV incidence of the scion as ToLCV incidence was recorded in both grafts and nongrafted
controls.
Anatomical studies of graft union revealed the formation of thick callus and
establishment of vascular connection between stock and scion in the form of vascular
bridges at 20 DAP planting. At 40 DAP, differentiation of vascular tissues were initiated
in all the grafts and 60 DAP well established vascular connections were observed. Callus
thickness and cell wall thickness generally reduced whereas dimensions of xylem vessel
and phloem tissue increased from 20 DAP to 60 DAP in all the grafts.
In the experiment 3, eight high yielding hybrids identified from experiment 2 were
evaluated in rainshelter during rainy season for yield and quality. Compared to open field,
plant height, average fruit weight, crop duration and yield of the grafts generally increased
inside the rainshelter. However, the days to flowering, days to first harvest, TSS and acidity
of grafts reduced compared to open field. There was significant variation among the grafts
for yield and quality when grown inside rainshelter. Arka Apeksha on Haritha recorded the
highest plant height among the grafts. Arka Abhed on Haritha recorded the highest average
fruit weight, fruit yield and crop duration (120.47g, 4.49kg, 167.20 days) which was on
par with Arka Samrat on Haritha (117.78g, 4.33kg, 167.80 days). The highest TSS was
recorded in the graft of Arka Apeksha on Haritha and acidity was highest in Sampurna on
Surya. None of the grafts recorded bacterial wilt incidence when grown inside rainshelter.
ToLCV incidence was highest in Arka Samrat on Haritha and Arka Rakshak on Surya
whereas, Sampurna on Surya and Arka Abhed and Lakshmi on Haritha recorded zero per
cent incidence.
Economic analysis was performed for growing the grafts inside rainshelter and the
graft of Arka Abhed on Haritha recorded the highest B:C ratio of 2.03. All the grafts
realized a B:C ratio greater than 1.50 indicating the economic viability of growing grafts
inside rainshelter.
From the study, it can be concluded that grafting is an economic, effective and
quick method for the management of bacterial wilt and the brinjal rootstocks used in the
study can be successfully utilized for grafting tomatoes when grown in bacterial wilt
affected areas. Apart from imparting resistance they also enhanced the yield of the tomato
hybrids without impairing the fruit quality.
Vegetable Science
Rootstocks on yield
Bacterial wilt
F1 hybrids
Tomato
635.6 / REM/IN Ph.D
Influence of rootstocks on yield, quality and bacterial wilt resistance in F1 hybrids of Tomato - Vellanikkara Department of Vegetable Science, College of Agriculture 2024 - 167,xxxi,xiip.
Ph.D
Tomato production in the tropics and subtropics is often hampered by the incidence
of various pests and diseases. Among these, bacterial wilt caused by the soil-borne bacteria
Ralstonia solanacearum poses a significant problem for tomato growers in Kerala. The
warm, humid, tropical climate and acidic soil conditions prevailing in the state provide a
favorable environment for wide spread occurrence of bacterial wilt in the state. Growing
resistant varieties have been identified as one of the most effective management strategy.
However, the development of bacterial wilt-resistant varieties or hybrids is challenging due
to the quantitative nature of the trait, its linkage to small fruit size, and the diversity of
pathogen strains. Therefore, an effective alternative is grafting tomato cultivars having high
production potential onto bacterial wilt resistant rootstocks. In addition to providing
complete resistance to bacterial wilt, grafting also helps in harnessing improved yield. In
this context, the present study was undertaken with the objectives of identifying bacterial
wilt-resistant rootstocks for tomatoes, evaluating the performance of the grafts for yield,
quality, and bacterial wilt resistance, and determining their suitability for growing in the
rainshelter.
In experiment 1, ten F1 hybrids of tomato were collected and evaluated in sterilized
medium for their yield and quality. Hybrids exhibited significant variation for yield and
quality traits. Among the hybrids significantly high plant height was exhibited by Arka
Apeksha. Days to flowering and harvest was minimum in Lakshmi. Arka Rakshak
exhibited highest root length and spread followed by Arka Apeksha. Average fruit weight
was significantly high in Arka Abhed (97.56g) followed by Arka Samrat (89.68g). Lakshmi
recorded significantly highest fruit yield per plant (3.28 kg) which was on par with Arka
Samrat (2.86 kg) and Arka Abhed (2.78 kg) followed by Arka Rakshak (2.65 kg),
Sampurna (2.62 kg) and Arka Apeksha (2.59 kg). Fruit quality traits such as lycopene,
vitamin C, TSS was the highest in Arka Apeksha. Sampurna recorded the highest acidity
and total phenol was the highest in COTH3. NSC 620B recorded the highest
Orthodihydroxy (OD) phenol and the lowest solasodine content was recorded in Arka
Apeksha.
Among the hybrids the highest bacterial incidence was recorded in Shivam (72.50 %) and
the hybrid Arka Abhed recorded zero per cent incidence. Tomato Leaf Curl Virus (ToLCV)
incidence was highest in COTH3 whereas, six hybrids Lakshmi, Sampurna, Arka Rakshak,
Arka Abhed, Arka Samrat and Arka Apeksha was completely free from ToLCV incidence.
In the experiment 2, six high yielding tomato hybrids from the experiment
1 (Lakshmi, Arka Samrat, Arka Abhed, Arka Rakshak, Sampurna and Arka Apeksha) were
grafted on four brinjal rootstocks viz., Surya, Haritha, SM 3, SM 116 and two Solanum
torvum rootstocks (KAU-1and TNAU-1). These grafts were evaluated for their yield,
quality and bacterial wilt resistance in bacterial wilt sick field. Plant height, girth of graft
(60 DAP), root length and spread, average fruit weight were significantly improved in the
grafted plants compared to their non-grafted controls. The highest plant height was
recorded in the grafts on SM 116 and Haritha and the lowest plant height was recorded on
SM 3 irrespective of the scion. Girth of graft was significantly high when grafted on Haritha
in all the hybrids which was followed by the grafts on Surya. Root length and spread were
also significantly high in grafts on Haritha followed by the grafts on Solanum torvum
rootstocks. Grafts on Haritha recorded the highest overall average fruit weight which was
on par with the grafts on Surya. Days to flowering and days to harvest were delayed in the
grafted plants compared to the non-grafted controls. However, significant improvement
was recorded in the crop duration of grafted plants compared to non-grafts. Fruit yield was
significantly improved compared to non-graft control on Haritha, Surya and SM 116 in all
the hybrids. Arka Rakshak (4.17 kg) , Lakshmi (3.98 kg), Arka Samrat (3.85 kg), Arka
Abhed (3.83 kg) and Arka Apeksha (3.76 kg) exhibited highest fruit yield per plant on
Haritha, whereas, Sampurna showed the highest fruit yield per plant on Surya (3.75 kg).
Among the 36 graft combinations, Arka Rakshak, Lakshmi, Arka Samrat, Arka Abhed,
Arka Apeksha grafted on Haritha and Arka Rakshak, Sampurna, Lakshmi on Surya
recorded the highest yield per plant and performed on par with each other.
Total Soluble Solids (TSS) of the fruits of grafted plants were on par with that of
non-grafted control in all hybrids. Acidity increased in the fruits of grafts compared to the
non-grafts. Lycopene content of the grafts were on par with non-grafted control except in
the grafts of Sampurna on Haritha and Solanum torvum rootstocks. Fruits of grafted plants
also recorded a decrease in vitamin C compared to non-grafted control. However, vitamin
C content of fruits of grafts on Haritha and Surya were on par with that of the non-grafted
control in all the hybrids except Lakshmi. Total Phenol, OD Phenol and Solasodine content
increased significantly in grafted plants compared to non-grafted control. Sensory
evaluation of fruits of grafted and non-grafted plants indicated only non-significant
difference between grafts and non-grafted control. Overall acceptability was similar or
higher in grafts compared to non-grafts except in the grafts of Lakshmi and Sampurna on
Solanum torvum rootstocks.
Grafts on the brinjal rootstocks Surya, Haritha, SM3 and SM 116 recorded zero
percent incidence of bacterial wilt. Whereas grafts on Solanum torvum rootstocks (TNAU-
1 and KAU- 1) recorded 6.67-13.33 per cent incidence. Rootstocks did not influenced the
ToLCV incidence of the scion as ToLCV incidence was recorded in both grafts and nongrafted
controls.
Anatomical studies of graft union revealed the formation of thick callus and
establishment of vascular connection between stock and scion in the form of vascular
bridges at 20 DAP planting. At 40 DAP, differentiation of vascular tissues were initiated
in all the grafts and 60 DAP well established vascular connections were observed. Callus
thickness and cell wall thickness generally reduced whereas dimensions of xylem vessel
and phloem tissue increased from 20 DAP to 60 DAP in all the grafts.
In the experiment 3, eight high yielding hybrids identified from experiment 2 were
evaluated in rainshelter during rainy season for yield and quality. Compared to open field,
plant height, average fruit weight, crop duration and yield of the grafts generally increased
inside the rainshelter. However, the days to flowering, days to first harvest, TSS and acidity
of grafts reduced compared to open field. There was significant variation among the grafts
for yield and quality when grown inside rainshelter. Arka Apeksha on Haritha recorded the
highest plant height among the grafts. Arka Abhed on Haritha recorded the highest average
fruit weight, fruit yield and crop duration (120.47g, 4.49kg, 167.20 days) which was on
par with Arka Samrat on Haritha (117.78g, 4.33kg, 167.80 days). The highest TSS was
recorded in the graft of Arka Apeksha on Haritha and acidity was highest in Sampurna on
Surya. None of the grafts recorded bacterial wilt incidence when grown inside rainshelter.
ToLCV incidence was highest in Arka Samrat on Haritha and Arka Rakshak on Surya
whereas, Sampurna on Surya and Arka Abhed and Lakshmi on Haritha recorded zero per
cent incidence.
Economic analysis was performed for growing the grafts inside rainshelter and the
graft of Arka Abhed on Haritha recorded the highest B:C ratio of 2.03. All the grafts
realized a B:C ratio greater than 1.50 indicating the economic viability of growing grafts
inside rainshelter.
From the study, it can be concluded that grafting is an economic, effective and
quick method for the management of bacterial wilt and the brinjal rootstocks used in the
study can be successfully utilized for grafting tomatoes when grown in bacterial wilt
affected areas. Apart from imparting resistance they also enhanced the yield of the tomato
hybrids without impairing the fruit quality.
Vegetable Science
Rootstocks on yield
Bacterial wilt
F1 hybrids
Tomato
635.6 / REM/IN Ph.D