TY - BOOK AU - Remzeena, A AU - Anitha, P (Guide) TI - Influence of rootstocks on yield, quality and bacterial wilt resistance in F1 hybrids of Tomato U1 - 635.6 PY - 2024/// CY - Vellanikkara PB - Department of Vegetable Science, College of Agriculture KW - Vegetable Science KW - Rootstocks on yield KW - Bacterial wilt KW - F1 hybrids KW - Tomato N1 - Ph.D N2 - 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 UR - https://krishikosh.egranth.ac.in/handle/1/5810220775 ER -