The ability of CROPGRO-Tomato model to simulate the growth characteristics of Thomas F1 tomato cultivar grown under open field conditions

There are few studies about the ability of CROPGRO-Tomato model to simulate tomato growth under field conditions as a function of both local weather and soil conditions. The aim of this work was to calibrate the CROPGRO-Tomato model, included in the Decision Support System for Agrotechnology Transfer (DSSAT) software, for the Thomas F1 indeterminate tomato cultivar grown under open field conditions at two locations in the Czech Republic with different soil and climate conditions. Additionally, this paper focuses on modelling the impact of compound weather events (CEs) on the growth characteristics of the hybrid field tomato variety. The genotype file, including the main parameters of crop phenology and plant growth, was adapted to the Thomas F1 indeterminate tomato cultivar. The CROPGRO-Tomato model was calibrated by inputting the soil characteristics, weather data and crop management data and then by adjusting the genetic coefficients to simulate the observed Leaf Area Index (LAI) and Above Ground Biomass (AGB) from transplanting to harvest under the farmers' field conditions. The comparison of the LAI simulated by the model and measured under field conditions showed adequate representation with the root mean square error of 0.86 and 1.11 m2/m2. Although there was a good fit for LAI and AGB between the simulated and measured data during the first part of the growing season, increasing differences were found in the growing season with cool-wet and/or hot-dry thresholds of CEs.

Effect of post-harvest temperature of tomato ‘Rinka 409’ on quality and autofluorescence during overripening

Japanese tomato cultivar ‘Rinka 409’ is suitable for harvesting at a fully ripe stage since it remains firm at the stage, resulting in longer shelf life. However, it is difficult to estimate the quality change because its color does not change after the fully ripe stage. For ‘Momotaro,’ we previously proposed a fluorescence-based indicator of overripening; however, its suitability for another cultivar, ‘Rinka 409’, and its relationship with temperature and quality were unclear. Therefore, in this study, we investigated the appropriateness of this fluorescence-based index for the above purposes. In 2021, 45 tomato seedlings planted in 2020 were harvested at the fully ripe stage and used for experiments. Weight loss and firmness were evaluated to determine the quality of the tomatoes. The post-harvest temperatures were set as 10, 17, and 25 °C. The results showed that the rate of weight loss increased linearly, whereas the firmness decreased exponentially. For non-destructive estimation of these properties, the excitation-emission matrix (EEM) was measured in the range of 250–460 nm and 280–750 nm for the excitation and emission, respectively. ‘Rinka 409’ showed a strong fluorescence emission at 400 nm/620 nm of the excitation/emission, respectively, regardless of days and temperature. The fluorescence intensity, as well as the firmness, decreased exponentially. Thus, a linear relationship was observed between them. The firmness of ‘Rinka 409’ can be estimated using a simpler linear regression model using this method than previous researches.

Physiological and Biochemical Responses of Tomato Plants Grafted onto Solanum pennellii and Solanum peruvianum under Water-deficit Conditions

Grafting using suitable rootstocks mitigates the adverse effects caused by environmental stresses such as water deficit in the tomato crop. Solanum pennellii and Solanum peruvianum, the wild relatives of tomato, are used as rootstocks due to their tolerance to water deficit and soil-borne diseases. This study focused on evaluating physiological and biochemical responses of tomato plants grafted onto S. pennellii and S. peruvianum rootstocks during water deficit. The commercial tomato cultivar ‘HM 1823′ (HM) either self-grafted (HM/HM) or grafted onto S. pennellii (HM/PN), S. peruvianum (HM/PR), and ‘Multifort’ (HM/MU) rootstocks were subjected to water-deficit stress by withholding irrigation for eight days. The performance of the grafted plants under water deficit was evaluated using physiological and biochemical parameters in vegetative tissues of the grafted plants. Plants grafted using S. pennellii (PN) and S. peruvianum (PR) rootstocks showed higher values of water potential (Ѱw), relative water content (RWC), net photosynthetic rate (A), and leaf water use efficiencies (WUE) compared to HM, HM/HM, and HM/MU. Plants grafted onto tomato wild relatives showed the lowest malondialdehyde (MDA) and proline content. This study demonstrated that the rootstocks of wild tomato relatives reduced the effect of water deficit to a greater extent through better physiological, metabolic, and biochemical adjustments than self-grafting plants.

History of development and results of selection of Solanaceae crops in FSBSI FSVC

The article presents a brief history of the establishment of the Laboratory of Plant Breeding and Seed Production of Solanaceae Crops of FSBSI FSVC. The process of development of tomato, pepper, eggplant and physalis breeding is shown from the beginning of the establishment until the present time. Practical selection of Solanaceae crops in FSBSI FSVC is directly connected with the name of Academician VASKhNIL A.V. Alpatyev, who is the founder of scientific research on thermophilic crops. On the basis of conducted scientific researches the technique of creation of cold-resistant, early-ripening cultivars of tomato was developed, including influence of certain conditions on parental forms and hybrid material from its first generations to increase adaptability to new, not characteristic conditions of selected material. Subsequently, this technique was applied to the breeding of sweet pepper, eggplant and physalis. Interspecific hybridisation was used to enrich the gene pool of Solanaceous crops. As a result of distant hybridization, the following cultivars were created: the original tomato cultivar Severyanin with large parthenocarpic fruits on 1 and 2 racemes; an anadrous mutant for use in breeding; ultra-rapid, short-stage forms for obtaining heterosis effect; the cultivar Vkusny with increased content of dry matter in fruits. On the basis of interspecific hybrid of Ph. ixocarpa x Ph. angulata, the cultivars Dessert and Lakomka, characterized by high yield and resistance to diseases, high content of sugars, pectin and absence of bitterness, are created. Types of pepper Capsicum chinense, C. frutescens and C. annuum were used to create resistant forms to viral diseases. Involvement of wild eggplant species (Solanum aethiopicum, S. macrocarpon) to the breeding process allowed to obtain hybrid combinations with flavonoids content 1,3 times higher and phenolcarboxylic acids 1,6–1,7 times higher than in S. melongena.The development of theoretical bases ofSolanaceae crops breeding for resistance to biotic and abiotic stressors, as well as for high quality production, allowed to create a series of cosmopolitan cultivars, which at present are in demand, both in production and as a source material. The current scientific priorities are to use innovative biotechnology and molecular marking methods to accelerate the breeding process and improve selection efficiency.

Effect of Plant density and Fertilizer Application Rates on Growth, Fruit Yield and Quality of Tomato (Solanum lycopersicum L.) in Greenhouse Condition

Plant density and fertilization are key practices for improving the fruit quality and yield of vegetables grown in greenhouses. The experiment was performed to investigate the effects of density and fertilization on the fruit yield and quality, economic efficiency of Solanum lycopersicum L. at Duc Trong district of Lam Dong province. The density (50,000; 33,000; 25.000 plants ha-1) and the fertilizer rates (240N – 100P2O5 – 275K2O; 300N – 125P2O5 – 344K2O; 360N – 150P2O5 – 413K2O kg and 420N – 175P2O5 – 482K2O kg ha-1) were studied in a completely randomised split plot design with three blocks. The fertilizer rate (420N – 175P2O5 – 482K2O kg ha-1) was produced the highest height (562.39 cm), fruit setting rate (69.87%), number of fruit per plant (95.65 fruits), average fruit weight (106.37 g), fruit yield (441.11 tons ha-1) and marketable fruit yield (204.31 tons ha-1). The density (25,000 plants ha-1) gave the highest fruit setting rate (75.35%), number of fruit per plant (94.84 fruits), average fruit weight (113.24 g), individual fruit yield (10.02 kg per plant) and fruit yield (501.17 tons ha-1). The combination of density (25,000 plants ha-1) and fertilizer rate (420N – 175P2O5 – 482K2O kg ha-1) have the highest fruit yield (613.5 tons ha-1), marketable fruit yield (223.91 tons ha-1) and rate of return (2.44). In addition, this combination was the best density and fertilizer level management strategy for greenhouse-grown Lahay 334 tomato cultivar in Lam Dong province, Vietnam.

Development of a New Essential Oil-Based Technology to Maintain Fruit Quality in Tomato

In this study, a new technology was tested for its efficacy in the conservation of tomato fruits. An initial experiment was conducted to determine the effects of eugenol on the main quality parameters of Raf tomato fruits; then, a main experiment was performed to test the effectiveness of the new technology. In both experiments, fruits of the tomato cultivar Raf at the mature green stage were used. The preliminary experiment demonstrated the effectiveness of eugenol in maintaining fruit quality during the postharvest life of the fruit. In the main experiment, the fruits were packed using a sachet filled with a mixture consisting of 10:1:1 clinoptilolite clay, ground clove buds, and activated charcoal. This mixture was evaluated against a commercial ethylene scavenger composed mainly of KMnO4-impregnated sepiolite. Three lots of fruits were used: One batch was considered as the control, where the fruits were not packed but kept in an open box at room temperature. The fruits in the other two batches were packed in 2 L PET containers with lids at a rate of three fruits per container, and a sachet of ground cloves and a commercial scavenger was added inside each container in each batch. The containers were kept at room temperature, and the following main quality parameters were analyzed: ethylene production rate, firmness, color, content of soluble solids, and pigments. The results showed that ground clove buds led to a reduction in ethylene production which was associated with a delay in maturation and could be a good alternative for use in the active fruit packaging of horticultural products.

Transcriptome and physiological analysis of increase in drought stress tolerance by melatonin in tomato

Drought stress seriously affects tomato growth, yield and quality. Previous reports have pointed out that melatonin (MT) can alleviate drought stress damage to tomato. To better understand the possible physiological and molecular mechanisms, chlorophyll fluorescence parameters and leaf transcriptome profiles were analyzed in the “Micro Tom” tomato cultivar with or without melatonin irrigation under normal and drought conditions. Polyethylene glycol 6000 (PEG6000) simulated continuous drought treatment reduced plant height, but melatonin treatment improved plant growth rate. Physiological parameter measurements revealed that the drought-induced decreases in maximum efficiency of photosystem II (PSII) photochemistry, the effective quantum yield of PSII, electron transfer rate, and photochemical quenching value caused by PEG6000 treatment were alleviated by melatonin treatment, which suggests a protective effect of melatonin on PSII. Comparative transcriptome analysis identified 447, 3982, 4526 and 3258 differentially expressed genes (DEGs) in the comparative groups plus-melatonin vs. minus-melatonin (no drought), drought vs. no drought (minus-melatonin), drought vs. no drought (melatonin) and plus-melatonin vs. minus-melatonin (drought), respectively. Furthermore, 101 DEGs were common to these four comparative groups. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed that DEGs in the four comparative groups were involved in multiple metabolic processes and closely related to hormone signal transduction and transcription factors. These results provide new insights into a probable mechanism of the melatonin-induced protection of photosynthesis and enhancement of drought tolerance in tomato plants.

Ions and Organic Solutes as Implicated in the Ameliorative Effect of Exogenous Application of Calcium on Salt Stressed Tomato (Lycopersicon esculentum Mill.) Plants

Aims: This study evaluated the role of sodium, potassium, proline and soluble sugars accumulation in the ameliorative effect of an exogenous application of calcium on the detrimental effect of salinity on tomato plants. Study Design: The experiment was implemented as a Completely Randomized Design (RCD) with four treatments and three replications. Place and Duration of Study: The experiment was realized in a green house of the Faculty of Agronomical Sciences, University of Abomey-Calavi, Benin Republic from June to July 2020. Methodology: Three weeks old plants of the tomato cultivar “Padma” was submitted in pots to four treatments comprising the control (without NaCl); salt stress (120 mM NaCl) and a combination of 120 mM NaCl and exogenous application of 40 mM CaSO4 or Ca (NO3)2 by irrigation every two days. Plants growth, sodium (Na) and potassium (K) as well as proline and soluble sugars contents of leaves and roots were determined after two weeks. Results: Salt effect reduced significantly plant growth at P =.05, root K content at P =.05 and leaf K/Na ratio at P =.01 whereas it increased significantly leaf Na at P =.05 and root soluble sugars content at P =.05. The application of exogenous calcium (Ca) induced a significant amelioration of plant growth at P =.01 more marked with CaSO4 than with Ca (NO3)2. This treatment induced a significant decrease at P =.01 in leaf and root Na content and a significant increase at P =.05 in root K content only for CaSO4, a significant increase at P =.01 in leaf K/Na ratio and a significant increase at P =.01 in leaf and root proline content only for Ca(NO3)2. Conclusion: The ameliorative effect of both forms of calcium was due mainly to sodium (Na) exclusion from leaves and potassium (K) accumulation associated to a maintain of high K/Na ratio mainly in leaves. The importance of proline accumulation as an indicator of this ameliorative effect was associated only to Ca(NO3)2.

The Sw5a gene confers resistance to ToLCNDV and triggers an HR response after direct AC4 effector recognition

Several attempts have been made to identify antiviral genes against Tomato leaf curl New Delhi virus (ToLCNDV) and related viruses. This has led to the recognition of Ty genes (Ty1-Ty6), which have been successful in developing virus-resistant crops to some extent. Owing to the regular appearance of resistance-breaking strains of these viruses, it is important to identify genes related to resistance. In the present study, we identified a ToLCNDV resistance (R) gene, SlSw5a, in a ToLCNDV-resistant tomato cultivar, H-88-78-1, which lacks the known Ty genes. The expression of SlSw5a is controlled by the transcription factor SlMyb33, which in turn is regulated by microRNA159 (sly-miR159). Virus-induced gene silencing of either SlSw5a or SlMyb33 severely increases the disease symptoms and viral titer in leaves of resistant cultivar. Moreover, in SlMyb33-silenced plants, the relative messenger RNA level of SlSw5a was reduced, suggesting SlSw5a is downstream of the sly-miR159-SlMyb33 module. We also demonstrate that SlSw5a interacts physically with ToLCNDV-AC4 (viral suppressor of RNA silencing) to trigger a hypersensitive response (HR) and generate reactive oxygen species at infection sites to limit the spread of the virus. The “RTSK” motif in the AC4 C terminus is important for the interaction, and its mutation completely abolishes the interaction with Sw5a and HR elicitation. Overall, our research reports an R gene against ToLCNDV and establishes a connection between the upstream miR159-Myb33 module and its downstream target Sw5a to activate HR in the tomato, resulting in geminivirus resistance.

An Integrated Diagnostic Approach for Citrus Exocortis Viroid

BackgroundCitrus exocortis viroid (CEVd) is a circular single-stranded RNA pathogen consists of around 370 nucleotides and leads to a severe disease showing bark scaling symptom on citrus crops, which leads to yield decrease and economic loss. Since the absence of viroid-encoded proteins, methods for CEVd detection mainly counts on bioassays or nucleic acid-base approaches. In order to validate the CEVd disease, here we developed an integrated diagnostic protocol. MethodsCEVd transcripts were inoculated onto two susceptible cultivars of Solanum lycopersicum L., cv. Rutgers and cv. Double-Fortune, seedings. After inoculation, total RNAs of the two tomato cultivars were extracted to detect CEVd infection by dot blot hybridization, one-step reverse transcription PCR (one-step RT-PCR) and real-time reverse transcription PCR (real-time RT-PCR). In addition, the symptom development of both cultivars was recorded weekly. ResultsThe tomato cultivar Rutgers rather than Double-Fortune or others was selected as a suitable CEVd-indicator plant and the bio-index score was established based on epinasty, vein necrosis, leaf size reduction and stunting symptoms. In addition, the isolate of CEVd that collected from citrus field could rapidly and consistently cause the index symptoms on Rutgers. As expected, CEVd could be specifically and sensitively detected in both tomato and citrus plants by dot-blot hybridization and RT-PCR technologies, including one-step RT-PCR and real-time RT-PCR. Furthermore, we found that the levels of CEVd genomic RNA or CEVd derived small RNAs are correlated to symptom severity. ConclusionsIn this study, we developed an integrated detection method for CEVd and revealed potential underlying viroid-host interactions.