1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Impact of seed exposure to simulated microgravity on growth and development in tomato (Solanum lycopersicum L.)(Department of Seed Science and Technology, College of Agriculture, Vellayani, 2025-02-12) Ram Ambiya; Beena, RThe study titled “Impact of seed exposure to simulated microgravity on growth and development in tomato (Solanum lycopersicum L)” was undertaken with the objective to evaluation of morpho-physiological, anatomical and biochemical changes in growth and development in tomato after exposure of seeds to different simulated microgravity. The experiments were conducted using seeds of the tomato variety 'Anagha,' which were exposed to simulated microgravity conditions. Microgravity is characterized by a reduction in gravitational force, which can create stress in organisms and plants, affecting their metabolism, growth, and development. Simulated microgravity was created using a Random Positioning Machine (RPM), which rotates seeds slowly at speeds of (25-40 rpm), reducing the effect of gravity to around 10-3 g. Seeds were exposed to (4hr, 8hr, 12hr, 24hr and control different durations of simulated microgravity. Two experiments were carried out in a completely randomized design (CRD). In both experiments, the seeds were sown, and the seedlings were transplanted into pots 30 days after sowing. They were maintained under standard cultural practices, including irrigation. The study was conducted across two growing seasons: Summer and Kharif. The results revealed that exposure to simulated microgravity significantly influenced tomato growth. The simulated microgravity treatment (T4) enhanced the germination rate, which reached (95%) in the summer and (97%) in the kharif season by the seventh day. Additionally, treatment (T3) exhibited the highest seedling vigor in the summer (13.75), while treatment T4 showed the highest seedling vigor in the kharif season (15.32). Moreover, treatment T4 also displayed the highest germination speed in both seasons. In the summer, the earliest flowering occurred in treatment T4 (23.5 DAT), while in the kharif season, treatment T3 exhibited early flowering (24.75 DAT). The pollen viability in treatment T4 was enhanced, exceeding (80%) during the kharif season. Furthermore, the study reported an increase in chlorophyll content under simulated microgravity conditions, with treatment T4 reaching (1.785 mg/g) in the kharif season. Various enzymatic activities, such as peroxidase, superoxide dismutase, and catalase, increased, while malondialdehyde (a marker of lipid peroxidation) also increased. These responses suggest that the plants developed better stress tolerance under microgravity conditions. The study found that simulated microgravity significantly influenced various growth and biochemical parameters in tomato plants. In the summer season, treatment T1 showed the highest ascorbic acid content (12.62 mg g-1), plant height (87.175 cm), fresh weight (378.75 g), and root growth. In the kharif season, treatment T3 exhibited the highest ascorbic acid content (20.37 mg/g-1), anthocyanin (0.448 mg/g), and total sugar content (1.305 mg/g), while treatment T4 had the highest lycopene content (3.143 µg/g), plant height (98.4 cm), and yield (842.25 g). Root length, volume, fresh, and dry weight were significantly enhanced under treatment T3 in the kharif season. Overall, seeds exposed to simulated microgravity showed increased growth, improved biochemical composition, and enhanced fruit yield, highlighting the potential of microgravity as a tool for crop improvement in both terrestrial and extraterrestrial agriculture. In conclusion, this study demonstrates that simulated microgravity has a positive impact on the growth, development, and biochemical characteristics of tomato plants. Improved germination rates, enhanced seedling vigor, increased chlorophyll content, and higher yields were observed, suggesting that microgravity could be a useful tool for crop improvement. Furthermore, increased enzymatic activity and better root growth under stress conditions indicate the potential applications of simulated microgravity in agriculture, both on land. This is the first of its kind of study performed on Anagha seeds and such studies on other species developed within KAU can lead to interesting results and important clues on enhancing crop yield and productivity. Future research should focus on long-term exposure to simulated microgravity and its effects on other crop species. This knowledge can help optimize crop production in space missions and challenging terrestrial environments, contributing to sustainable food security on earth and beyond.Item Impact of seed exposure to simulated microgravity on growth and development in tomato (Solanum lycopersicum L.)(Department of Seed Science and Technology, College of Agriculture, Vellayani, 2025) Ram Ambiya.; Beena, RThe study titled “Impact of seed exposure to simulated microgravity on growth and development in tomato (Solanum lycopersicum L)” was undertaken with the objective to evaluation of morpho-physiological, anatomical and biochemical changes in growth and development in tomato after exposure of seeds to different simulated microgravity. The experiments were conducted using seeds of the tomato variety 'Anagha,' which were exposed to simulated microgravity conditions. Microgravity is characterized by a reduction in gravitational force, which can create stress in organisms and plants, affecting their metabolism, growth, and development. Simulated microgravity was created using a Random Positioning Machine (RPM), which rotates seeds slowly at speeds of (25-40 rpm), reducing the effect of gravity to around 10-3 g. Seeds were exposed to (4hr, 8hr, 12hr, 24hr and control different durations of simulated microgravity. Two experiments were carried out in a completely randomized design (CRD). In both experiments, the seeds were sown, and the seedlings were transplanted into pots 30 days after sowing. They were maintained under standard cultural practices, including irrigation. The study was conducted across two growing seasons: Summer and Kharif. The results revealed that exposure to simulated microgravity significantly influenced tomato growth. The simulated microgravity treatment (T4) enhanced the germination rate, which reached (95%) in the summer and (97%) in the kharif season by the seventh day. Additionally, treatment (T3) exhibited the highest seedling vigor in the summer (13.75), while treatment T4 showed the highest seedling vigor in the kharif season (15.32). Moreover, treatment T4 also displayed the highest germination speed in both seasons. In the summer, the earliest flowering occurred in treatment T4 (23.5 DAT), while in the kharif season, treatment T3 exhibited early flowering (24.75 DAT). The pollen viability in treatment T4 was enhanced, exceeding (80%) during the kharif season. Furthermore, the study reported an increase in chlorophyll content under simulated microgravity conditions, with treatment T4 reaching (1.785 mg/g) in the kharif season. Various enzymatic activities, such as peroxidase, superoxide dismutase, and catalase, increased, while malondialdehyde (a markerof lipid peroxidation) also increased. These responses suggest that the plants developed better stress tolerance under microgravity conditions. The study found that simulated microgravity significantly influenced various growth and biochemical parameters in tomato plants. In the summer season, treatment T1 showed the highest ascorbic acid content (12.62 mg g-1), plant height (87.175 cm), fresh weight (378.75 g), and root growth. In the kharif season, treatment T3 exhibited the highest ascorbic acid content (20.37 mg/g-1), anthocyanin (0.448 mg/g), and total sugar content (1.305 mg/g), while treatment T4 had the highest lycopene content (3.143 μg/g), plant height (98.4 cm), and yield (842.25 g). Root length, volume, fresh, and dry weight were significantly enhanced under treatment T3 in the kharif season. Overall, seeds exposed to simulated microgravity showed increased growth, improved biochemical composition, and enhanced fruit yield, highlighting the potential of microgravity as a tool for crop improvement in both terrestrial and extraterrestrial agriculture. In conclusion, this study demonstrates that simulated microgravity has a positive impact on the growth, development, and biochemical characteristics of tomato plants. Improved germination rates, enhanced seedling vigor, increased chlorophyll content, and higher yields were observed, suggesting that microgravity could be a useful tool for crop improvement. Furthermore, increased enzymatic activity and better root growth under stress conditions indicate the potential applications of simulated microgravity in agriculture, both on land. This is the first of its kind of study performed on Anagha seeds and such studies on other species developed within KAU can lead to interesting results and important clues on enhancing crop yield and productivity. Future research should focus on long-term exposure to simulated microgravity and its effects on other crop species. This knowledge can help optimize crop production in space missions and challenging terrestrial environments, contributing to sustainable food security on earth and beyond.Item Impact of biofertilizers and nutrients on the quality and shelflife of tomato (Solanum lycopersicum L.) and on the fruit shelflife regulator (SIFSR) gene expression under elevated CO2 condition(Department of Plant Physiology, College of Agriculture , Vellayani, 2024-03-16) Haripriya, S.; Manju, R VThe study entitled “Impact of biofertilizers and nutrients on the quality and shelflife of tomato (Solanum lycopersicum L.) and the Fruit Shelflife Regulator (SlFSR) gene expression under elevated CO2 condition” was undertaken with the objective of elucidating the effects of biofertilizers and nutrients on the quality and shelf-life of tomato and the Fruit Shelf-life Regulator (SIFSR) gene expression under elevated CO2 condition. The experiment was conducted using the Open Top Chamber (OTC) system facility in the Department of Plant Physiology, College ofAgriculture, Vellayani during 2022-2023. In the experiment, quality and shelf-life of tomato under elevated CO2 environment, as influenced by nutrients and biofertilizers were evaluated. The experiment was laid out in CRD consisting 5 treatments with three replications under ambient and elevated conditions. The treatments comprised of T1: POP, KAU+AMF, T2: POP, KAU+ PGPR Mix-1,T3: POP, KAU+Azolla T4: POP, KAU+50 ppm B + 50 ppm Zn+60 ppm Ca water spray (40, 55 and 70 DAS.) and T5: POP,KAU Control. The experimental results revealed, plant height after 75 days of sowing, specific leaf area and total dry matter increased significantly under elevated CO2 condition. Foliar spray with 50 ppm B + 50 ppm Zn + 60 ppm Ca along with POP, KAU recommendation recorded the highest plant height at 75 DAS. AMF treated plants were found to improve specific leaf area at 60 DAS and 75 DAS. Root to shoot ratio was reduced under elevated CO2 condition compared to ambient condition. Among the treatments, soil incorporation of PGPR before transplantation of seedlings resulted in the highest accumulation of dry matter. Among the physiological and biochemical parameters, total chlorophyll content, total carbohydrate content and chlorophyll stability index recorded higher values under elevated CO2 compared to open condition. However, a significant reduction was noted in total soluble protein content under elevated CO2 compared to open condition. PGPR mix 1 treated plants had recorded the highest chlorophyll and total carbohydrate content but plants foliar sprayed with 50 ppm B+50 ppm Zn+60 ppm Ca recorded the best results with respect to chlorophyll stability index. Exposure to elevated CO2 was found to increase the days for first flowering. Application of biofertilizers and nutrients reduced the days to flowering significantly. Plants came to flowering 40 DAS in the cases of PGPR mix-1 treated plants under eCO2 and AMF treated plants under aCO2. Due to high temperature associated with CO2 enrichment, pollen viability was lost and there was no fruit production inside OTC. Yield parameters such as number of fruits, fruit weight, fruit setting percentage and yield per plant showed significant difference among treatments. Among the treatments, PGPR mix-1 treated plants recorded significant increase in fruit weight, number of fruits and yield. Application of biofertilizers and nutrients had significant impact on quality of fruit and the most effective treatment was incorporation of PGPR mix-1 along with POP, KAU in terms of increased accumulation of lycopene, β-carotene, vitamin C, total sugars, pectin, moisture content, shelf-life and reduced physiological loss in weight. Foliar spray had the same impact as that of PGPR mix-1 treatment in the cases of vitamin C and beta carotene contents. Though AMF was found to increase P content of the fruits significantly, Fe content in fruits was influenced by foliar sprayed and PGPR mix-1 treatment.CO2 enrichment was found to have no influence on expression levels SlFSR gene in leaf tissues but the application of biofertilizers and nutrients was found to affect expression levels in fruits. Lowest level of expression was noted in fruits collected from azolla treated plants under ambient condition. The increase in atmospheric temperature due to increasing CO2 concentration can hasten perishability in the case of farm products. Efforts towards shelf-life extension to make fruit safe for long periods, keeping its original quality is of paramount importance today. The present programme clearly indicates that the shelf-life of tomato variety Vellayani Vijay can be enhanced by 85% through the soil incorporation of PGPR mix-1 before transplanting. This is a great achievement considering the higher perishability of tomato. Application of the biofertilizer, azolla which resulted in the 22.22% increase in shelf-life lead to down regulation of the GRAS transcriptional factor, SlFSR which controls fruit shelf-life by regulating expression of cell wall modifying genes and metabolism of pectin and cellulose. The significant extension of shelf-life achieved through the application of PGPR and AMF could be mediated through the down regulation of ethylene biosynthesis and cell wall degrading enzyme activities. Combined application of calcium, boron and zinc contributes towards firmness of fruit tissues and extended shelf-life to the same degree. The findings of the present programme revealed that application of azolla, PGPR mix-1 and AMF and combined application of calcium, boron and zinc improved the quality and shelf-life of tomato significantly. The result also proves SlFSR gene as a potential biotechnological target for the control of fruit shelf-life. The outcome of the programme will help to develop agricultural practices for improving the shelf-life and quality of tomato which is of paramount importance in the scenario of increasing atmospheric temperature and climate change.Item Screening of tomato (Solanum lycopersicum L.) genotypes for high temperature tolerance(Department of Plant Breeding and Genetics, College of Agriculture , Vellanikkara, 2024-05-28) Anjali Joy, S L; Deepthy Antony, P.Tomato (Solanum lycopersicum L., 2n=24) cultivation is prevalent in both tropical and sub-tropical climates. For optimum yield and quality, the crop needs a climate that is dry and fairly cold, and are sensitive to hot and humid climate. In the current context of global warming, high temperature is considered as a major threat to agriculture with profound consequences on yield and quality. Plant morphology, physiology, biochemistry, and molecular pathways are disrupted by heat stress. The optimum temperature range for fruiting in tomato is narrow viz., 15 to 21 °C at night and 30 to 35 °C during the day. Depending on the stage of growth, a daily mean temperature between 21 and 24 °C is ideal for tomato. The current study, ‘Screening of tomato (Solanum lycopersicum L.) genotypes for high temperature tolerance’ was conducted during 2021–2023 at the Department of Plant Breeding and Genetics, College of Agriculture, Vellanikkara. Thirteen NBPGR accessions, four hybrids from IIHR, Bengaluru, eight improved lines from the World Vegetable Centre, Taiwan, and five KAU varieties made up the 30 tomato genotypes used in the study. Genotypes were subjected to laboratory screening for thermotolerant traits, and selected genotypes were taken for polyhouse screening. Field screening was done during summer for evaluating the performance of all the genotypes for thermotolerance and yield traits. All experiments were laid out in completely randomized design with three replications for laboratory and polyhouse screening, and two replications for field screening. Physiological traits (electrolyte leakage and membrane stability) and morphological traits (pollen viability, pollen germination, style length and style protrusion) were evaluated under laboratory and polyhouse screening. Plant height and yield characters (days to 50 per cent flowering, fruit set per cent, deformed fruits per cent, number of fruits per plant, average fruit weight and fruit yield per plant) were recorded under field screening along with morphological traits. Arka Samrat, EC 538153, AVTO 1314, and Manuprabha were superior genotypes for electrolyte leakage and membrane thermostability under laboratory screening. EC 528368, EC 620486, Akshaya, and Vellayani Vijay outperformed other varieties in terms of pollen viability and germination at 40 ℃. Superior genotypes based on pollen viability and style protrusion were EC 315489, EC 523851, EC 528368, EC 538153, EC 567305, EC 620486, EC 620488, EC 636872, AVTO 0922, AVTO 1725 and Vellayani Vijay. Based on style protrusion and pollen germination at 40 ℃, and their combination with other traits, 14 genotypes (AVTO 1702, AVTO 1706, AVTO 1725, AVTO 1726, EC 315489, EC 538153, EC 549819, EC 620428, EC 620486, EC 620488, EC 620494, EC 636872, Manulakshmi, and Vellayani Vijay) were selected for polyhouse evaluation. Polyhouse screening was done inside a non-ventilated structure to ensure temperature build up, and an increase of 4-5℃ was found inside the structure compared to ambient condition. All genotypes showed a decrease in pollen viability and germination under polyhouse compared to the open condition. All the genotypes, except Vellayani Vijay showed an increase in style protrusion. Superior genotypes with respect to electrolyte leakage were AVTO 1725, AVTO 1702, AVTO 1706, EC 620428, EC 538153, and Manulakshmi. EC 549819, EC 620428, and EC 636872 were considered as superior genotypes based on style protrusion and pollen germination, as they are important thermotolerant traits. Field screening was carried out to assess the yield traits along with thermotolerant traits in summer season. EC 528360 was found to be superior in pollen viability and style length. Style protrusion increased in all breeding lines and hybrids, except EC accessions. Genotypes like Akshaya, Arka Rakshak, AVTO 1314, and EC 636872 were significantly superior for fruit set percentage compared to Vellayani Vijay. Deformed fruits percentage showed no significant variation between genotypes, and was more than 80 per cent for every genotype examined. Vellayani Vijay and EC 636872 exhibited higher fruit number per plant. Arka Rakshak had a significantly higher average fruit weight than all other genotypes. Pollen viability, style protrusion, number of fruits per plant, fruit set, average fruit weight, and fruit yield per plant all demonstrated high GCV and PCV. The GAM and high heritability of the remaining characters suggested that they had additive gene effects and can be used for selection. Correlation analysis of observations recorded for field screening showed that style length and style protrusion had a significant positive correlation with fruit set per cent, average fruit weight and fruit yield per plant. Molecular markers did not reveal polymorphism in the present study and needs further investigation to identify reliable markers. AVTO 0922, EC 523851, EC 528368, EC 549819, EC 620494, EC 636872, and Vellayani Vijay were identified as heat-tolerant genotypes based on laboratory, polyhouse, and open field evaluations. Akshaya, Anagha, Arka Rakshak, AVTO 0301, AVTO 1314, AVTO 1707, Manuprabha, and Vellayani Vijay had higher yields and, with the exception of AVTO 0301, all had high fruit set percentage in the summer season. In general, thermotolerant genotypes performed moderate to poor in terms of yield traits. Hence, the study demonstrated that specific donors for thermotolerance traits and yield traits needs to be included in crop improvement programmes for heat tolerance in tomato. Vellayani Vijay had heat tolerance traits as well as superior yield traits indicating its suitability for incorporation in crop improvement programmes.Item Management of elevated CO 2 induced high temperature through nutrient and biofertilizer application in tomato (Solanum lycopersicum L.)(Department of Plant Physiology, College of Agriculture , Vellayani, 2021-12-17) Arunima, A S; R V, ManjuThe study entitled “Management of elevated CO 2 induced high temperature through nutrient and biofertilizer application in tomato (Solanum lycopersicum L.)” was undertaken with the objective of improving flowering and fruit set of tomato under elevated CO 2 condition through nutrient and biofertilizer application. The experiment was conducted using the Open Top Chamber (OTC) facility at the Department of Plant Physiology, College of Agriculture, Vellyani during 2020-2021. In the experiment, flowering and fruiting in tomato under elevated CO 2 environment, as influenced by nutrients and biofertilizers were evaluated. The experiment was laid out in CRD with nine treatments and three replications. The treatments comprised of T 1 :50 ppm B + 50 ppm Zn + water spray, T 2 :75 ppm B + 75 ppm Zn, T 3 : POP 150% N:125%P:125% K, T 4 : Azolla (soil application), T 5 :Azolla biofertilizer extract (20%) (foliar application), T 6 : Azolla biofertilizer extract(20%)(seed treatment), T 7 :POP, KAU+ PGPR1, T 8 : Control (water spray) and T 9 : Absolute control. Experimental results revealed that plant height, number of branches, number of leaves and specific leaf area increased significantly under elevated CO 2 condition at 75DAS. Among the treatments, foliar spray with 50ppmB+50ppm Zn+ water spray at 40, 55and 70 DAS recorded higher plant height (57.56%) at 75DAS. Nutrient application of 150%N:125%P:125%K found to improve the number of branches (91.82%), leaves (98.56%) and specific leaf area (40.03%) at 75DAS. Among the physiological and biochemical parameters, total chlorophyll content, total carbohydrate, photosynthetic rate, water use efficiency, chlorophyll fluorescence, chlorophyll stability index and proline content recorded higher values inside OTC compared to open condition. However, a significant reduction was noted in transpiration rate and total soluble protein content inside OTC compared to open condition. The foliar spray of 50ppm B+50ppm Zn+ water spray recorded high values for chlorophyll content (1.58 mg g -1 ) and cell membrane stability index (53.83%) compared to open condition at 75DAS. The application of POP 150% N:125% P:125% K recorded significantly higher photosynthetic rate (21.03μmol CO 2 m -2 sec -1 ), total carbohydrate(50.04mgg -1 ), chlorophyll stability index(135.38%) and chlorophyll fluorescence (0.74Fv/Fm). Also foliar application of 20% Azolla biofertilizer extract was found to significantly improve the relative water content (96.15%) and water use efficiency(6.82 mmol CO 2 mol -1 H 2 O) in tomato plants under elevated CO 2 conditions. Inside OTC, flowering delayed by 2 days and the total number of flower clusters (5.96) also increased compared to control (4.12). Reduction in pollen viability (82.42%) observed at higher CO 2 compared to control. But it was found to improve under treatment T1 (50ppm B+ 50ppm Zn + water spray) which resulted in highest fruit setting percentage (53.01%) as against the control (39.92%). Fruiting was delayed by 3 days inside OTC. However, the fruit weight was found to increase with water spray (54.46%), extra NPK(55.89%) and foliar spray of 50ppm B+ 50ppm Zn+ water spray(57.51%). Foliar application of Azolla biofertilizer extract (20%)(T5), 150% N:125% P:125% K(T3) than the recommended dose, as well as foliar application 50ppm B + 50ppm Zn+ water spray (T1) improved the yield per plant by 55.79%, 63.08% and 65.22% respectively compared to control. All these treatments also improved the quality parameters like lycopene, vitamin C, beta carotene and minerals (P, Fe) in tomato fruits under elevated CO 2 condition. The present study indicated the improved performance of tomato variety Vellayani vijay upon exposure to elevated CO 2 . But flowering, fruit set and ultimately the total yield were negatively influenced by elevated CO 2 induced high temperature. The impact of application of extra N, P and K than the recommended doses as well as foliar application of B and Zn indicate the changing nutrient requirement of tomato under the current scenario of increasing atmospheric CO 2 concentration. The response of experimental plants to foliar application of Azolla extract (20%) strongly suggest the effectiveness of this biofertilizer in overcoming the impacts of elevated CO 2 induced high temperature and thereby improving the plant performance. Recommendations based on the best treatments can be developed by extending the study to field condition since the treatments were found to improve the yield and quality even under ambient conditionItem Controlled abiotic stress induction in tomato (Solanum lycopersicum L.) and its influence on the phenylalanine ammonia- lyase (Pal) gene expression(Department of Molecular Biology and Biotechnology, College of Agriculture, Vellayani, 2023-11-06) Bhagya Shibu.; Manju, R VThe study entitled “Controlled abiotic stress induction for biofortification in tomato (Solanum lycopersicum L.) and its influence on the Phenylalanine ammonia lyase (PAL) gene expression” was conducted at the College of Agriculture, Vellayani, Thiruvananthapuram, during 2022-2023. The objective of this study was to know the impact of application of mild soil moisture stress and elevated CO2 associated high temperature for biofortification of tomato and its influence on the expression levels of the key enzyme PAL, involved in the biosynthetic pathway of nutritionally relevant secondary metabolites in tomato. The experiment was conducted in a completely randomized design in pot culture with four replications with tomato, variety “Vellayani Vijay”. Plants were maintained under open field conditions (390 ppm) and under the elevated CO2 of 500 ppm in the Open Top Chamber (OTC) facility at the Department of Plant Physiology. The study consisted of four treatments (i) exposure to mild moisture stress [withdrawal of irrigation for 2 days 1 month after transplanting] (T1), (ii) exposure of vegetative phase to eCO2 (500 ppm) associated high temperature for 1 week, [1 month after transplanting] (T2), (iii) exposure of the entire vegetative phase to eCO2 (500 ppm) associated high temperature (T3) and (iv) control (T4) conditions. Observations on physiological and biochemical parameters were taken 60 days after transplanting. Growth parameters, yield, and quality were observed at the time of harvest. The expression analysis of the PAL gene was done in leaf tissues of experimental plants using Real-Time PCR after exposure to both stresses. Plants subjected to mild moisture stress and eCO2 exposure showed a significant reduction in RWC and % leakage. Exposure to mild moisture stress resulted in a significant increase in all the biochemical parameters like reducing sugar (52.55%), phenol content (68.7%), carotenoid (24.4%), alkaloid content (19.1%) and ascorbic acid (12.6%) in leaf tissues of tomato. Exposure to mild moisture stress resulted in a significant increase in all the biochemical parameters like reducing sugar (25.74%), phenol content (76.9%), carotenoid content (84.2%%), alkaloid content (20.8%), lycopene content (32.1%) and ascorbic acid (47.8%) in fruits. Elevated carbon dioxide exposure to a period of 1 week also had a positive impact on phenol, lycopene, and ascorbic acid in fruits though carotenoid and alkaloid contents showed a reducing trend with this stress factor. Both stress factors resulted in a reduction in root weight, shoot weight, and total dry matter. The root/shoot ratio was found to increase under mild moisture stress (14.28%). Phenylalanine ammonia-lyase (PAL) is a key enzyme involved both in the phenylpropanoid and flavonoid pathways. In the present study, PAL gene expression showed 1.64, 1.96, and 3.39 fold increase under mild moisture stress, eCO2(1 week), and eCO2 (vegetative phase) exposure respectively compared to control. Exposure of tomato plants to mild moisture stress and elevated carbon dioxide showed an upregulated PAL gene expression. The result of the study showed that the application of mild moisture stress and exposure to eCO2 for a short period can result in biofortification in tomato variety Vellayani Vijay. Stress-induced overexpression of PAL can be associated with increased accumulation of secondary metabolites. The findings of the current study will help to develop low-cost strategies for biofortification in tomato which can make high quality farm products available to low-income consumers.Item Controlled abiotic stress induction in tomato (Solanum lycopersicum L.) and its influence on the phenylalanine ammonia- lyase (Pal) gene expression(Department of Molecular Biology and Biotechnology, College of Agriculture ,Vellayani, 2023-11-06) Bhagya ShibuThe study entitled “Controlled abiotic stress induction for biofortification in tomato (Solanum lycopersicum L.) and its influence on the Phenylalanine ammonia lyase (PAL) gene expression” was conducted at the College of Agriculture, Vellayani, Thiruvananthapuram, during 2022-2023. The objective of this study was to know the impact of application of mild soil moisture stress and elevated CO2 associated high temperature for biofortification of tomato and its influence on the expression levels of the key enzyme PAL, involved in the biosynthetic pathway of nutritionally relevant secondary metabolites in tomato. The experiment was conducted in a completely randomized design in pot culture with four replications with tomato, variety “Vellayani Vijay”. Plants were maintained under open field conditions (390 ppm) and under the elevated CO2 of 500 ppm in the Open Top Chamber (OTC) facility at the Department of Plant Physiology. The study consisted of four treatments (i) exposure to mild moisture stress [withdrawal of irrigation for 2 days 1 month after transplanting] (T1), (ii) exposure of vegetative phase to eCO2 (500 ppm) associated high temperature for 1 week, [1 month after transplanting] (T2), (iii) exposure of the entire vegetative phase to eCO2 (500 ppm) associated high temperature (T3) and (iv) control (T4) conditions. Observations on physiological and biochemical parameters were taken 60 days after transplanting. Growth parameters, yield, and quality were observed at the time of harvest. The expression analysis of the PAL gene was done in leaf tissues of experimental plants using Real-Time PCR after exposure to both stresses. Plants subjected to mild moisture stress and eCO2 exposure showed a significant reduction in RWC and % leakage. Exposure to mild moisture stress resulted in a significant increase in all the biochemical parameters like reducing sugar (52.55%), phenol content (68.7%), carotenoid (24.4%), alkaloid content (19.1%) and ascorbic acid (12.6%) in leaf tissues of tomato. Exposure to mild moisture stress resulted in a significant increase in all the biochemical parameters like reducing sugar (25.74%), phenol content (76.9%), carotenoid content (84.2%%), alkaloid content (20.8%), lycopene content (32.1%) and ascorbic acid (47.8%) in fruits. Elevated carbon dioxide exposure to a period of 1 week also had a positive impact on phenol, lycopene, and ascorbic acid in fruits though carotenoid and alkaloid contents showed a reducing trend with this stress factor. Both stress factors resulted in a reduction in root weight, shoot 84 weight, and total dry matter. The root/shoot ratio was found to increase under mild moisture stress (14.28%). Phenylalanine ammonia-lyase (PAL) is a key enzyme involved both in the phenylpropanoid and flavonoid pathways. In the present study, PAL gene expression showed 1.64, 1.96, and 3.39 fold increase under mild moisture stress, eCO2(1 week), and eCO2 (vegetative phase) exposure respectively compared to control. Exposure of tomato plants to mild moisture stress and elevated carbon dioxide showed an upregulated PAL gene expression. The result of the study showed that the application of mild moisture stress and exposure to eCO2 for a short period can result in biofortification in tomato variety Vellayani Vijay. Stress-induced overexpression of PAL can be associated with increased accumulation of secondary metabolites. The findings of the current study will help to develop low-cost strategies for biofortification in tomato which can make high quality farm products available to low-income consumers.Item Identification of superior tomato (Solanum lycopersicum L.) hybrids with high yield under water stress(Department of genetics and plant breeding, college of agriculture, Vellayani, 2023-11-14) Harisha, K.; Beena ThomasThe present study, entitled “Identification of superior tomato (Solanum lycopersicum L.) hybrids with high yield under water stress” was conducted in the Department of Genetics and Plant Breeding, College of Agriculture, Vellayani during 2021–2023 with the objective of screening of tomato (Solanum lycopersicum L.) hybrids for high yield under water stress condition. The materials for research were chosen from a previous project in the Department of Genetics and Plant Breeding. The experimental material included ten F1 hybrids, viz., Vellayani Vijay x Palakkad local, PKM-1 x Kuttichal local, PKM-1 x Palakkad local, PKM-1 x Kottayam local, Akshaya x Kuttichal local, Akshaya x Palakkad local, Akshaya x Kottayam local, Arka Meghali x Kuttichal local, Arka Meghali x Palakkad local and Arka Meghali x Kottayam local. These hybrids were evaluated in both field and pots to identify the F1 hybrid combination with superior performance for yield under water stress condition. The field experiment was laid out in a randomized block design (RBD) with ten treatments and three replications, and the pot experiment was conducted in a completely randomized design (CRD) with ten treatments and three replications. Water stress was imposed by restricting irrigation once in three days from the flowering stage onwards in both field and pot experiments. The analysis of variance was carried out for the characters under study, viz., plant height (cm), number of primary branches per plant, number of days to 50% flowering, number of flower cluster per plant, number of fruits per cluster, number of fruits per plant, fruit weight (g), yield per plant (g), relative water content, membrane stability index, total soluble solids (0Brix) and total acidity in both field and pot experiments. A significant difference was noticed for all the characters of F1 hybrids in both field and pot experiments. The mean performance of the F1 hybrids for the characters under study was recorded. The highest yield per plant was shown by Akshaya x Palakkad local, which also showed the maximum value for other characters like flower cluster per plant, fruits per cluster and fruits per plant in both field and pot experiments under water stress condition. The F1 hybrid Arka Meghali x Kottayam local showed the minimum value for most of the characters in both field and pot experiments under water stress condition, hence it is noted as drought susceptible. Qualitative analysis was carried out for F1 hybrids. The Maximum total soluble solids was observed for PKM-1 x Palakkad local, and the maximum total acidity was shown by Arka Meghali x Kottayam local in the field under water stress condition. In the pot experiment, the maximum total soluble solids was recorded by Akshaya x Palakkad local, and the highest total acidity was recorded by PKM-1 x Kottayam local. Analysis of physiological traits showed that the F1 hybrid, Akshaya x Palakkad local recorded the highest relative water content and membrane stability index in both field and pot experiments under water stress condition, indicating that this F1 hybrid is tolerant to electrolyte loss under water stress condition. Genetic parameters were also estimated for all the characters under study. The highest PCV and GCV were shown by yield per plant, primary branches per plant, total acidity, and flower cluster per plant in the field experiment. The characters fruits per cluster and total acidity showed the maximum PCV and GCV in the pot experiment. Under both field and pot conditions, high heritability with high genetic advance was observed for yield per plant, flower cluster per plant, fruits per plant, fruits per cluster and fruit weight. Correlation and path analysis were also performed for the selected traits. All characters showed a significant positive correlation with yield per plant, except days to 50% flowering and membrane stability index, which showed a negative association with the yield per plant in the field experiment. In pot studies, all characters showed a positive association with yield per plant except membrane stability index, which showed a negative association with the yield per plant. The characters plant height, flower cluster per plant and fruits per plant showed a significant positive direct effects on yield per plant in both field and pot experiments. The present study revealed that the F1 hybrid Akshaya x Palakkad local showed superior performance for most of the characters in both field and pot experiments under water stress condition. Hence, this F1 hybrid is considered as water stress tolerant and can be utilized in further crop improvement programs.Item Breeding of ToLCV resistant high yielding tomato (Solanum lycopersicum L.) genotypes(Department of Plant Breeding and Genetics, College of Agriculture, Vellanikkara, 2023-05-15) Athira Sebastian; Deepthy Antony, PTomato (Solanum lycopersicum L.) is a warm season vegetable crop of solanaceae family, which is widely grown in India for use as vegetable as well as fruit. But, its production is hampered by disease incidence leading to severe crop loss. Among the diseases affecting tomato, whitefly transmitted tomato leaf curl virus disease (ToLCD) is very severe, and it can cause upto 100 per cent yield loss depending on stage of infection. As vector management using insecticides leads to environmental pollution and creates vulnerability, exploitation of host plant resistance is the best sustainable strategy to manage ToLCD. Hence, identified resistance sources can be utilised for the development of high yielding ToLCV resistant genotypes through hybridization programmes. In this context, the present study entitled “Breeding of ToLCV resistant high yielding tomato (Solanum lycopersicum L.) genotypes” was carried out during 2021 2023. Ten previously identified genotypes showing field resistance or carrying Ty genes (AVTO 0301, AVTO 0922, AVTO 1314, AVTO 1702, AVTO 1706, AVTO 1707, AVTO 1725, AVTO 1726, EC 519806 and Local Collection (Idukki)) were selected as source of resistance and were crossed with three agronomically superior released varieties viz., Akshaya, Manuprabha and Vellayani Vijay in Line x Tester mating design. Seventeen successful crosses along with parents and check variety, Anagha, were screened for ToLCV resistance in RBD design with two replications during March- June 2022. The disease incidence was assessed at 15, 30, 60 and 90 days after transplanting as per the score given by Banerjee and Kalloo (1987). Among the hybrids screened, Vellayani Vijay × EC 519806, Akshaya × AVTO 1726 and Akshaya × AVTO 1707 showed least Coefficient of Infection (CI) and were highly resistant under field condition. In the present study, the morphological characters affecting growth and yield such as growth habit, plant height, spread of the plant, number of primary branches per plant, days to flowering, fruit colour, fruit size, number of fruits per plant, number of locules per fruit, lycopene content, fruit weight and fruit yield per plant differed significantly among the hybrids. The crosses of EC 519806 followed by Akshaya × AVTO 1726 recorded the highest yield per plant. Moreover, the whitefly population assessment in the field also showed less whitefly infestation on Akshaya × AVTO 1726. Hybrids with significant positive Relative heterosis (RH), Heterobeltiosis (HB) and Standard heterosis (SH) for all growth and yield characters were obtained in the present study. Most of the hybrids exhibited significant SH for all the characters under study. And all the traits exhibited high heritability coupled with high genetic advance. Line x Tester analysis of nine F1’s, developed from three lines (Akshaya, Manuprabha and Vellayani Vijay) and three testers (AVTO 1707, EC 519806 and Local Collection (Idukki)), revealed significant sca effect for hybrids and significant gca effect for parents for days to flowering (Vellayani Vijay x EC 519806, Manuprabha x AVTO 1707); equatorial diameter and fruit size (Manuprabha × AVTO 1707); polar diameter (Vellayani Vijay × AVTO 1707); fruit weight (Akshaya × AVTO 1707); spread of the plant (Akshaya × Local Collection (Idukki), Manuprabha × EC 519806); number of fruits per plant and yield per plant (Vellayani Vijay × EC 519806). Significant sca effect was recorded for plant height (Manuprabha × AVTO 1707); equatorial diameter (Akshaya × EC 519806, Vellayani Vijay × Local Collection (Idukki)); polar diameter and fruit size (Akshaya × EC 519806, Akshaya × Local Collection (Idukki), Manuprabha × AVTO 1707); number of fruits per plant (Akshaya x Local Collection (Idukki), Manuprabha x AVTO 1707); number of primary branches per plant (Akshaya x EC 519806); spread of the plant (Manuprabha × AVTO 1707, Vellayani Vijay × Local Collection (Idukki)); yield per plant (Akshaya × AVTO 1707, Akshaya × Local Collection (Idukki), Manuprabha × AVTO 1707, Manuprabha × Local Collection (Idukki)). Although, significant gca for number of primary branches per plant (Manuprabha; Local Collection (Idukki)); number of fruits per plant (Vellayani Vijay; Local Collection (Idukki)) and spread of the plant (Akshaya; EC 519806, Manuprabha; Local Collection (Idukki)) was observed, their crosses did not have significant sca. Therefore, selection in segregating generations will be effective for these characters. Glandular and non glandular trichome density on both abaxial and adaxial leaf surfaces demonstrated that glandular abaxial trichome density is more effective for ToLCV resistance than adaxial trichomes. Among the hybrids, Akshaya × AVTO 1726 and Akshaya × AVTO 1707 had above average glandular and below average non glandular trichome density. To confirm ToLCV resistance, whitefly mediated artificial inoculation was done on the selected hybrids and observed that Akshaya × AVTO 1726 was highly resistant under artificial screening as well. All crosses of EC 519806 (except Akshaya × EC 519806) and Local Collection (Idukki) were susceptible under artificial screening. Screening for six reported Ty genes using the primers 562 JB/830 JB, SCAR2, P6-25, TY-1/3_K, C2_AT5g51110, AVRDC-TM273 and SLM 10-46 linked to ToLCV resistance genes Ty 1, Ty 2, Ty 3, Ty 1/3, Ty 4, ty 5 and Ty 6 respectively, revealed presence of Ty 1, Ty 2, Ty 3 and Ty 1/3 in all the crosses of AVTO 1726 and AVTO 1707. Whereas, AVTO 0922, AVTO 0301 and AVTO 1314 contributed Ty 1 and Ty 2; Ty 1, Ty 2 and Ty 3; Ty 1 and Ty 3 genes respectively in their crosses. None of the markers showed resistant amplicon in EC 519806. In the present study, none of the genotypes exhibited presence of resistant amplicon for Ty 4. AVRDC-TM273 linked to ty 5 failed to detect polymorphism in the genotypes. Whereas, resistant allele of the marker linked to Ty 6 was amplified only in Local Collection (Idukki) and its crosses. The present study revealed that Akshaya × AVTO 1726 is a very promising hybrid with high yield, ToLCV resistance large sized fruits. Akshaya × EC 519806, Akshaya × AVTO 1707 and Manuprabha × AVTO 1707 are high to medium yielding hybrids with moderate resistance to ToLCV. Vellayani Vijay × EC 519806 was the highest yielding genotype. Therefore, these crosses can be forwarded to further generations to identify superior genotypes from segregating generationsItem Standardization of spacing and fertilizer recommendation for tomato (Solanum lycopersicum L.) varieties in AEU 8(Department of Vegetable Science, College of Agriculture, Vellayani, 2024-03-02) Sreelakshmi, S; Sarada, S