Tomato Hybrids Research Articles

Studies on Heterosis Employing Leaf Curl Resistant Mutant for Several Horticultural Traits Related to Earliness and Yield in Tomato (Solanum lycopersicum L.)

Aim: Determine the degree of heterosis for the yield and earliness component qualities in order to generate hybrids for early and high yield through heterosis breeding.
 Study Design: The experiment was laid out in Randomized Block Design with three replications.
 Place and Duration of Study: The experiment was conducted at the ICAR-Indian Institute of Vegetable Research in Varanasi, which is located about 20 kilometres to the southwest of the city on the Ganga River's bank at an elevation of 128.93 metres above mean sea level and lies between 82.52 degrees east and 25.10 degrees north (MSL). The experiment was carried out in late Kharif in 2015 and 2016, as well as in the summer of 2017.
 Methodology: In total 33 crosses were developed using 14 tomato genotypes, including the tomato leaf curl virus susceptible variety Punjab Chhuhara and the advanced breeding line H-88-78-2, a mutant resistant to leaf curl with altered inflorescence and ripening, in order to evaluate the heterosis for earliness and yield attributes. Three cultivars were the male parents (testers), while eleven cultivars were the female parents (line). As a result, 33 tomato hybrids were developed adopting the line tester method. Each line in this design is paired with one of the "t" testers using a random sample of "I" lines. Over the better parent, the mid parent, and the standard/check (Arka Rakshak) heterosis was estimated according to Singh and Chaudhary (1979).
 Results: Based on results from both seasons, the cross P7×P13 showed the highest significant negative heterosis per cent for earliest traits like days to first flower (-46.43, -43.80), days to 50% flowering (-35.66, -50.00), and days to first ripening (-30.09, -28.74) over superior parent in first and second seasons, respectively. The hybrid P9×P13 displayed the highest significant heterosis per cent for the features linked to yield in the first and second seasons, for the number of fruits per plant (71.78, 592.04) and yield per plant (75.11, 425.88). The outcome showed that minimum days of first blooming and first ripening are indicative of earliness, and the maximum yield per plant was associated with the highest possible number of fruits per plant.
 Conclusion: Based on the results of both seasons, it was determined that the tomato mutant (P13) generated hybrids had low and negative heterosis for qualities associated to earliness and high and positive heterosis for traits related to yield. As a result, the number of fruits per plant and the number of days before the first fruit ripens are better measures of output and earliness. By altering this particular attribute, it would be possible to improve productivity with early crops. Breeders should therefore concentrate largely on the number of fruits and the days to first ripening in order to achieve a high and early yield.

The role of grafting in the productivity of tomato of extended cycle

Relevance. The purpose of the research: to study the effect of technological method (grafting) on tomatos productivity in the conditions of protected soil in the Tyumen region. Research objectives: based on the study of tomato rootstocks for the studied graft, to identify the most productive rootstock for subsequent use in LLC “Greenhouse facility “TyumenAgro” . Subject of research: protected ground conditions.The object of research: tomato hybrids F1 Maxeza, F1 Trovanzo and F1 Complis (as grafts), F1 Maxifort and F1 Emperador (as a rootstocks). The article also provides information on the use of the technological method of grafting when growing tomatoes in protected soil conditions in LLC “Greenhouse facility “TyumenAgro””.Methods. The productivity of tomatoes is taken into account from1 m2 in three-fold repetition. Crop accounting is carried out separately for each option as the fruit ripens, after 5–7 days. The results of crop accounting are processed by the method of variance analysis presented by B.A. Dospekhov. Results. In the course of research, it was found that the cultivation of tomato hybrids in conditions of lowvolume hydroponics, subject to phytosanitary measures, allows to increase the yield and quality of fruits. The highest yield for the crop cycle of 2018–2021 was observed in plants with Maxesa F1 graft and Emperador F1 rootstock, it amounted to 226.47 kg/m2. Based on the research, elements of a new technology will be proposed, characterized by significantly higher quality indicators of tomato productivity formation.

Relative Water Content, Proline, and Antioxidant Enzymes in Leaves of Long Shelf-Life Tomatoes under Drought Stress and Rewatering.

Some physiological, oxidative, and antioxidant enzymatic patterns were assessed in plants of three local Sicilian landraces of long shelf-life tomatoes ('Custonaci', 'Salina', and 'Vulcano'), as compared to the commercial tomato hybrid 'Faino' (control). Three water treatments were considered in open-field: DRY (no irrigation); IRR (long-season full irrigation); REW (drought/rewatering cycles). During the growing season, soil water deficit (SWD) was estimated, and relative water content (RWC), specific leaf area (SLA), proline and malondialdehyde (MDA) content, and glutathione peroxidase (GPX), catalase (CAT), and superoxide dismutase (SOD) activities were measured in leaves. Differently from control, RWC in local landraces exhibited a similar pattern in REW and DRY, indicating a low capacity to re-hydrate after rewatering. Positive correlation of proline content vs. SWD in all local landraces highlights an osmotic adjustment occurring in these tomatoes in response to limited soil water content. Long shelf-life tomatoes suffered minor oxidative stress due to severe soil water deficit, as revealed by the lower levels of MDA with respect to the control. Significant correlation of CAT vs. SWD for all tomatoes indicates that this antioxidant enzyme, among those analyzed, may be considered as a biomarker for a water stress condition more than for oxidative stress due to water deficit.

Tissue Culture Techniques for the Production of Interspecific Hybrids in Poland: History and Achievements

Abstract Interspecific hybridization is a significant plant evolutionary process and, concomitantly, a frequently used method to broaden the genetic variability of species and genetically improve crops. However, in distant crosses, many prezygotic and postzygotic barriers are encountered that prevent free, uncontrolled gene flow between species. Therefore, various experimental methods exploiting tissue culture, such as in vitro fertilization, embryo rescue, and protoplast fusion, have been developed to raise hybrids that cannot be obtained naturally through conventional approaches. Professor Maciej Zenkteler of the Adam Mickiewicz University in Poznań pioneered the use of tissue culture in Poland to overcome barriers to sexual crossing. In the mid-1960s, he employed in vitro pollination in which pollen grains were directly applied onto the surface of exposed ovules as the primary method to bypass prezygotic barriers and in vitro culture of isolated ovules and developing embryos (embryo rescue) to overcome post-zygotic barriers. These approaches proved effective for species possessing numerous ovules and large placentas, such as representatives of the families Caryophyllaceae, Solanaceae, and Brassicaceae. Soon thereafter, these methods were extended to other Polish institutes and universities and applied for crop improvement, such as for the production of intergeneric hybrids between Salix and Populus species, resynthesis and broadening of the genetic variability of oilseed rape ( Brassica napus L.), and the generation of new interspecific hybrids of Allium . In the late 1970s, Professor Zenkteler was the first to undertake protoplast fusion. At that time, it appeared that no incompatibility could exist at the fusion level and that somatic hybridization would supersede the possibilities offered by sexual hybridization; however, the reality turned out to be slightly harsh. Nonetheless, successful regeneration of different interspecific hybrids of potato, tomato, or gentians has been achieved by Polish research groups thus far.

Over-expression of GGP1 and GPP genes enhances ascorbate content and nutritional quality of tomato

L-Ascorbic acid (AsA), a strong antioxidant, serves as an enzyme cofactor and redox status marker, modulating a plethora of biological processes. As tomato commercial varieties and hybrids possess relatively low amounts of AsA, the improvement of fruit AsA represents a strategic goal for enhanced human health. Previously, we have suggested that GDP-L-Galactose phosphorylase (GGP) and L-galactose-1-phosphate phosphatase (GPP) can serve as possible targets for AsA manipulation in tomato (Solanum lycopersicon L.) fruit. To this end, we produced and evaluated T3 transgenic tomato plants carrying these two genes under the control of CaMV-35S and two fruit specific promoters, PPC2 and PG-GGPI. The transgenic lines had elevated levels of AsA, with the PG-GGP1 line containing 3-fold more AsA than WT, without affecting fruit characteristics. Following RNA-Seq analysis, 164 and 13 DEGs were up- or down-regulated, respectively, between PG-GGP1 and WT pink fruits. PG-GGP1 fruit had a distinct number of up-regulated transcripts associated with cell wall modification, ethylene biosynthesis and signaling, pollen fertility and carotenoid metabolism. The elevated AsA accumulation resulted in the up regulation of AsA associated transcripts and alternative biosynthetic pathways suggesting that the entire metabolic pathway was influenced, probably via master regulation. We show here that AsA-fortification of tomato ripe fruit via GGP1 overexpression under the action of a fruit specific promoter PG affects fruit development and ripening, reduces ethylene production, and increased the levels of sugars, and carotenoids, supporting a robust database to further explore the role of AsA induced genes for agronomically important traits, breeding programs and precision gene editing approaches.

Investigating NAC Transcription Factor Role in Redox Homeostasis in Solanum lycopersicum L.: Bioinformatics, Physiological and Expression Analysis under Drought Stress.

NAC transcription factors regulate stress-defence pathways and developmental processes in crop plants. However, their detailed functional characterization in tomatoes needs to be investigated comprehensively. In the present study, tomato hybrids subjected to 60 and 80 days of drought stress conditions showed a significant increase in membrane damage and reduced relative water, chlorophyll and proline content. However, hybrids viz., VRTH-16-3 and VRTH-17-68 showed superior growth under drought stress, as they were marked with low electrolytic leakage, enhanced relative water content, proline content and an enhanced activity of enzymatic antioxidants, along with the upregulation of NAC and other stress-defence pathway genes. Candidate gene(s) exhibiting maximum expression in all the hybrids under drought stress were subjected to detailed in silico characterization to provide significant insight into its structural and functional classification. The homology modelling and superimposition analysis of predicted tomato NAC protein showed that similar amino acid residues were involved in forming the conserved WKAT domain. DNA docking discovered that the SlNAC1 protein becomes activated and exerts a stress-defence response after the possible interaction of conserved DNA elements using Pro72, Asn73, Trp81, Lys82, Ala83, Thr84, Gly85, Thr86 and Asp87 residues. A protein-protein interaction analysis identified ten functional partners involved in the induction of stress-defence tolerance.

Assessment Genetic Variability among Three Parents and Six Progenies of Tomato using Multivariate Analysis

Six tomato hybrids developed through diallel mating design and the three parents were obtained from the plant breeding section of Adekunle Ajasin University Akungba-Akoko and used to assess the genetic variability among them. The breeding materials were raised in the nursery for three weeks before transplanting. The hybrids and parents were laid out in a randomized complete block design (RCBD) replicated three times Seedlings were transplanted at a spacing of 60 x 30 cm between and within row. Variability estimates were highly significant (p< 5%) in all the 10 measured quantitative traits. The average fruit mean yield of 21.42 g was recorded for all the materials evaluated. Phenotypic variances were higher in magnitude than its corresponding genotypic variances apart from pericarp thickness which had the same value of 0.002 and 100% heritability. Factor scores and communality of the 10 traits of tomato obtained from the factor analysis showed that the first factor were positively loaded with eigen vectors for number of branches (0.818), number of fruits per cluster (0.803), plant height (0.776), fruit yield (0.748) and number of clusters per plant (0.731). The second factor was positively loaded with pericarp thickness (0.723) and number of clusters per plant (0.460). Factor three was only positively loaded with fruit weight (0.881). The communality ranged from 0.618 for fruit yield to 0.930 for fruit weight. Conclusively, traits such as fruit yield, pericarp thickness, fruit weight, number of locules per fruit, days to flowering and days to first fruit set are important traits that should be considered in further breeding programme in tomato.

Bayesian Ridge Algorithm for Brix Prediction in Industrial Tomato


 Tomato is one of the most significant vegetables in the world. Specifically, for the industrial tomato cultivation, the product is harvested when °Brix are at their peak. Technological advancements nowadays have made Decision Support Systems, based on Machine Learning Algorithms more applicable in a daily basis. Sustainable agriculture is evolving since farmers could be advised by this technology in order to take the best decision for their crops. Farmers who adopt this kind of technology will be able to know the quality of tomatoes. The implementation of a Decision Support System capable to predict the °Brix was conducted, based on various data from previous years, such as quality characteristics, the tomato hybrid used, weather conditions and soil data from the selected fields. Data came from fields from 6 different regions in Peloponnese, Greece over 3 cultivation periods. 12 different algorithms were tested in order to find which is the best one in terms of efficiency. Results of this research showed that the predicted °Brix were following the same pattern as the actual °Brix. This means that the DSS could advise the farmer about the ideal harvesting period where the °Brix will be maximized. The use of this DSS using real time weather data as an input will be a valuable tool for the farmers.

Effect of polycarbonate and agricultural film on production and biochemical compounds of tomato fruits

Tomato production has been enhanced significantly by management using intervention of temperature and radiation control in a protected environment. The use of plastic and/or polycarbonate covers changes the dynamics of production in tropical climate regions. The present study aimed to compare the following covered cultivation conditions: 1) polycarbonate plate (10 mm) box-shaped polycarbonate with a twin wall with anti UV-A and B (P), 2) agricultural film (AF) anti UV-A and UV-B, and 3) open field (OF) on the productivity and quality of Italian hybrid tomatoes. The study was carried out at Embrapa Agrossilvipastoril located in Sinop, Mato Grosso, Brazil. Four tomato hybrids and 03 distinct environments were used in a randomized block design in a subplot setup with five replications. The main factor was hybrid traits, and the subplots were environments with different covers. The highest productivity occurred in the P environment, with the hybrids Fascinio and Vedette with 66.64 and 55.84 t ha-1, respectively. The highest plant yield obtained was in the P environment, with an average of 3.15 kg per plant. Among the evaluated hybrids, the highest antioxidant potential was observed in Shanty, and for the content of carotenoids, lycopene, and vitamin C, no significant difference was observed between the evaluated hybrids. We can conclude that the use of polycarbonate plates box shaped with a twinwall or agricultural film in a protected tomato cultivation system under high temperature conditions increases the yield and qualitative potential of the Fascinio and Vedette hybrids.

Effect of Rootstock on ‘Tasti-Lee’ Tomato Yield and Fruit Quality in a High Tunnel Production System

Grafting tomatoes with vigorous rootstocks can be used to increase yield in high tunnels without significant soilborne disease pressure. However, evidence suggests that grafting with high-yielding rootstocks could compromise the accumulation of primary and secondary metabolites. ‘Tasti Lee’ is a hybrid tomato that is bred to have a superior fresh-eating quality and higher lycopene content. The objective of this experiment was to investigate the yield and fruit quality impacts of grafting ‘Tasti Lee’ with rootstocks with ranging vigor and typical yield performance in high tunnels. Nongrafted ‘Tasti-Lee’ and ‘Tasti-Lee’ scion grafted onto ‘Maxifort’, ‘DRO141TX’, ‘Fortamino’, ‘Estamino’, and ‘RST-04-106-T’ rootstocks were trialed in a high tunnel in Kansas for three consecutive growing seasons (2018–20). The trials were arranged in a randomized complete block design with four replications. Total yield, marketable yield, average fruit size, and distribution of fruit size classes were assessed. Red ripe tomato fruit were harvested to determine the soluble solids content, titratable acidity, lycopene content, vitamin C content, antioxidant capacity, and fruit firmness. ‘Maxifort’, ‘DRO141TX’, ‘Estamino’, and ‘Fortamino’ significantly increased marketable yield (kg/plant) by 31.5% to 47.0% more than nongrafted plants. In contrast, ‘RST-04-106-T’ did not lend any significant yield benefit. Regardless of the rootstock, grafting increased the marketable average fruit weight by 20 g. Grafting did not have significant effects on any of the fruit quality attributes assessed. However, the soluble solids content of fruit from plants grafted to ‘RST-04-106-T’ was 10% higher (P < 0.05) than that grafted to ‘Maxifort’, indicating that rootstock genotype can influence this quality trait. Our findings suggest that growers can graft the tomato ‘Tasti-Lee’ with select vigorous rootstocks to increase marketable yield without sacrificing fruit quality for high tunnel production.

SELECTION OF TOMATO VARIETIES AND HYBRIDS FOR CULTIVATION IN HYDROPONIC GREENHOUSES OF UZBEKISTAN

Growing vegetables in a low-volume crop on hydroponics is a modern, convenient and cost-effective way to grow plants. This way to prevent harmful substances from the soil from entering the plants is not to use the soil. Hydroponics is an ancient and at the same time modern and progressive method of growing plants without soil. This technology in the cultivation of vegetables provides equal conditions for all plants, which ensures a high level of production of standard products. There are no problems with soil acidity and agrochemical composition. It is possible to use the same types of fertilizers for different crops, growth is accelerated and yields increase, since physiological processes proceed much faster Our article provides data that in low-volume hydroponic greenhouses of Uzbekistan it is quite possible to cultivate from domestic tomato hybrids F1 Saihun, and F1 Zamira, which in terms of yield and quality are not inferior to the foreign hybrid F1 Salmaz.

GENETIC ANALYSIS AND HETEROTIC STUDIES IN TOMATO (SOLANUM LYCOPERSICUM L.) HYBRIDS FOR FRUIT YIELD AND ITS RELATED TRAITS

A study was conducted to determine the types of gene action of different yield-related traits in tomato and the combining ability in four advanced lines. The heterotic response in tomato hybrids was also assessed. Analysis of variance (ANOVA) revealed significant differences (P ≤ 0.05) among all the traits. General combining ability (GCA) and specific combining ability (SCA) for all chosen traits were computed using Griffing’s approach of diallel. Combining ability revealed the additive and non-additive genetic effects for all selected traits of advanced lines. T-1360 was found as a good general combiner for the number of cluster plant-1, average fruit weight, number of flowers cluster-1, fruit length, number of fruit cluster-1, and yield. The variance of the GCA to SCA ratio was found less than 0.5 for each trait, which confirmed the presence of non-additive gene action. The results revealed higher magnitudes of phenotypic coefficient of variance (PCV) than the genotypic coefficient of variance (GCV). The high magnitudes of heritability (72% to 92%) and genetic advance (36.63% to 139.72%) were found for the number of cluster plant-1, average fruit weight (g), the number of fruits cluster-1, and yield. Among all crosses, the cross ST-100 × T-1360 showed maximum positive heterosis over the mid parent (566.6%) and the better parent (455.5%). The identified tomato genotypes can be used further in different tomato breeding programs to improve fruit yield and other yield-related traits.

The use of biologically active substances in the technology of growing tomato F<sub>1</sub> Sherami in protected ground conditions

Relevance. The interest of vegetable producers in small-fruited tomato hybrids has been increasing in recent years. This is due to the high commercial qualities of fruits that do not crack, contain 3 times more sugars than large-fruited tomatoes, and their range of use for canning and salads has also been expanded.Goal: to identify effective options for the use of biologically active substances in conditions of extended turnover of winter greenhouses on tomato plantings F1 Sherami.Methods. Research was aimed at studying the effect of biologically active substances – sodium selenate at a concentration of 10-5, natural coniferous concentrate (2 mg/l), EpinExtra (0.2 mg/l) and their double and triple combinations on the productivity of cherry tomatoes F1 Sherami. The treatment of plants was carried out 4 times during the growing season – after picking, when planting seedlings in a permanent place, when pouring the first brush and during the mass harvest.Results. As a result of research, it was found that the use of the above drugs increases the productivity of tomato plants of the Sherami hybrid. The maximum yield according to the results of 2018 and 2019 was obtained on the variant using sodium Selenate + KHN + Epin-extra and averaged 288.1 t/ha. Also, the use of BAS had an effect on the content of dry matter, sugars and macronutrients.Conclusion. The effect of preparations of biologically active substances positively affected the growth and development of plants. The variation of the yield increase compared to the control ranged from 5.2 to 17.2 t/ha. The maximum yield of the Sherami hybrid tomato was obtained on the variant using sodium Selenate + KHN + Epin-extra, the increase was 19 t/ha, which made it possible to obtain an appropriate income level of more than 272 thousand rubles/ha.

Agronomic potential of BC1F2 populations of Santa Cruz dwarf tomato plants

The use of dwarf lines to obtain mini-tomato hybrid plants has led to agronomic and economic advantages. However, the benefits provided by dwarf parents in tomato hybrids of the Santa Cruz type remain unexplored. The aims of this study were to determine the agronomic enhancement in BC1F2 dwarf populations bearing characteristic fruit of the Santa Cruz type after the first backcross and to select populations with high agronomic potential and fruit quality. The experiment was conducted in a greenhouse using a randomized block design with 15 treatments and 4 replicates. Evaluated genetic materials included 11 BC1F2 dwarf tomato populations, both parents (recurrent and donor), and the cultivars (Santa Cruz Kada and Santa Clara). Traits evaluated included: mean weight, soluble solid concentration, number of locules, shape, pulp thickness, fruit longitudinal and transversal diameters, internode length, and plant height. Univariate, multivariate, correlation, and selection index analyses showed that mean fruit weight, transverse diameter, and pulp thickness increased significantly in dwarf populations after a single backcross, most of them exhibiting a fruit shape similar to that of the Santa Cruz type. The dwarf BC1F2 populations UFU-Sci#11 and UFU-Sci#12 showed high potential for obtaining lines and, subsequently, Santa Cruz type hybrids.

Biochemical and Molecular Evaluation of Some Tomato Hybrids in Salt Stress At The Growth Stage

Biochemical and Molecular Evaluation of Some Tomato Hybrids in Salt Stress At The Growth Stage

Soilless system: An approach for hybrid seed production in tomato (Solanum lycopersicum)

Soilless agriculture is one of the advanced techniques to cultivate plants without soil, with minimal water and nutrients, and helps in vertical growth of agricultural technology. It is an eco-friendly approach widely used for commercial cultivation of quality vegetables. An experiment was conducted at University of Agricultural Sciences, GKVK, Bengaluru, Karnataka during 2017–19 to evaluate the potentiality and suitability of the hydroponics (M2) and aeroponics (M3) methods over conventional method (M1) for hybrid seed production of tomato (Solanum lycopersicum L.). The experiment had 12 treatments comprising 3 methods of production, 2 parental lines (TAG 1F and TAG 2F) and 2 seed treatments (S1: Control and S2: thiram @2g/kg + chlorpyrifos @3g/kg). Hoagland nutrient solution with pH 5.5–6.5 was used for soilless systems. The results revealed that, among the parental lines, TAG 1F performed better under all the methods of hybrid seed production. Seed treatment increased the per cent survival rate to the tune of 3.26%. Aeroponics and hydroponics performed better than conventional method. Aeroponics showed significantly higher plant height (140.94 cm), fruit weight (124.54 g), total biomass (106.44 g) and test weight (0.39 g) while, hydroponics showed significantly higher number of fruit/plant (45.84) and SVI (2821). It is inferred that soilless agriculture could be a promising tool for quality and year-round healthy hybrid tomato seed production under protected cultivation.

The Exploitation of Heterosis for Yield and its Components of Tomato Hybrids for Use as Commercial Variety Development

A study was conducted in tomato to estimate the magnitude of heterosis for yield and yield related components at the Olericulture Division of Horticulture Research Centre, BARI during the winter season of 2021-22. Appreciable heterosis was found over better parents for all the traits studied in a desirable direction. Significant negative better parent heterosis was expressed for days to first flowering (4 combinations), days to 50% flowing (6 combinations), days to first harvest (7 combinations), and days to fruit maturity (8 combinations), while significant positive better parent heterosis was noticed in seven and three cross combinations for number of fruits per plant and single fruit weight, respectively. In our study, five cross combinations, viz., F1 203 (25.65%), F1 1501 (14.34%), F1 2101 (14.32%), F1 2301 (15.62%) and F1 2501 (16.22%) showed significantly positive better parent heterosis for higher yield. Six combinations were found to have significant positive heterosis with higher values in F1 1903 (21.95%), F1 2001 (19.62%), F1 2101 (12.84%) for TSS, while the significant negative better parent heterosis for TYLCV infection and leaf sucking pest infestation varied from -100% to 0.00%. Thus, it is evident from the data that, based on better parent heterosis of different yield and yield contributing traits, the cross combinations viz., F1 203, F1 1501, F1 2101, F1 2301 and F1 2501 may be investigated further for developing better hybrid tomato varieties.

Interspecific and Intraspecific Hybrid Rootstocks to Improve Horticultural Traits and Soil-Borne Disease Resistance in Tomato.

Tomato rootstocks are important to increase yield and control soil-borne pathogens, increasing vigor for a longer crop cycle and tolerance to biotic and abiotic stress. This study, conducted in the greenhouse of Sunchon National University during the period from 2019 to 2022, aimed to identify local soil-borne-disease resistant interspecific and intraspecific tomato hybrid rootstocks. The 71 interspecific hybrids (S. lycopersicum × S. habrochaites) showed that the germination vigor (GV) was less than Maxifort, except for several combinations. The germination rate (GP) of cross-species hybrids showed a different pattern according to the hybrid combinations, of which three combinations showed less than 30%. The horticultural traits, such as GV and GP, of the intraspecies hybrid (S. l × S. l) combination were significantly improved compared to that of Maxifort. In 71 combinations (S. l × S. h) and 25 combinations (S. l × S. l), MAS was used to evaluate the resistance of eight genes related to soil-borne pathogens, four genes related to vector-mediated pathogens, and three genes related to air-borne pathogens. The results showed that the new hybrid combination had improved resistance over the commercial-stock Maxifort. Therefore, interspecies and intraspecies hybrid techniques for breeding commercial rootstocks can be utilized as a way to improve horticultural properties and resistance to soil-borne diseases in tomato.

Double cross hybrids could substantially supersede single cross hybrids for yield, fruit quality and tolerance to tomato leaf curl virus disease

ABSTRACT Recombination of commercially available hybrids could produce desirable segregants that act as sources of new alleles for tomato breeding. Seven commercial single cross (SC) hybrids of tomato (Solanum lycopersicum L.) were crossed in a half diallel fashion to obtain 21 double cross hybrids (DC) to estimate combining ability, mode of gene action and extent of heterobeltiosis for fruit yield, processing qualities and tomato leaf curl virus (ToLCV) disease severity traits. Predominance of non-additive gene action occurred in the control for all characters except for total soluble solids (TSS) content in fruit that was conditioned by both additive and non-additive gene action. Improvement of most traits in DC hybrids over SC hybrids occurred. Maximum heterotic effect in DC hybrids was for vitamin C content followed by lycopene content, fruit yield per plant, titratable acidity content, number of fruit per plant and percent disease index of ToLCV. Two good combiners, ‘PAN-1286’ and ‘Devi’ among SC hybrids were identified based on general combining ability effects and average performance. Commercial exploitation of DC hybrids, ‘TO-1458 × L-37’ and ‘NS-501 × TO-1458’ following multilocational testing in the tropics and subtropics might be useful. High yielding, ToLCV disease tolerant DC hybrids could be exploited in segregating generations to identify elite multi-parent advanced generation inter-cross (MAGIC) populations.

Impact of Fertigation Schedule on Growth and Quality Parameters in Tomato

Nutrient availability to plants precisely can be done by combining cognitive irrigation systems with nutrient application, and proper scheduling of fertilizers is the mainstay for availability of appropriate amount of nutrients for plant growth. Based on the statement a, field experiment was carried out to evaluate the efficiency of fertigation influence on growth, physiological, quality and yield parameters of TNAU Tomato hybrid CO 4. The experiment consisting of seven treatments laid in randomized block design was replicated three times. `Fertigation was given at fortnightly interval with urea, MAP, MOP as a source of N, P& K in ten splits in 150 days. Significant differences were observed with regard to growth, physiological, quality and yield parameters. All the growth, physiological, and yield parameters were higher in tomato plants which received fertigation NPK @ 75% K + 100 % N&P. Lycopene content of tomatoes was increased to 4.73 mg 100 g-1 in fertigation NPK @ 75% K + 100 % N&P (T6). Ascorbic acid, Titratable acidity, TSS, β-carotene showed the highest value in treatment which received fertigation NPK @ 75% K + 100 % N&P.