Development Of Tomato Seedlings Research Articles

Effects of Light Intensity, Water Content, and the Application of Biochar Nanoparticles on the Growth and Development of Tomato Seedlings

This study investigates the effects of light intensity, water content, and the application of biochar nanoparticles (BNPs) on the growth and development of tomato seedlings to provide valuable insight into tomato cultivation. BNPs were prepared using rice straw. In this experiment, the light intensity was set at 350 μmol ·m−2 · s−1 (L1), 300 μmol ·m−2 · s−1 (L2), and 250 μmol ·m−2 · s−1 (L3). The irrigation amount was set at 150 mL/plant (W1) and 100 mL/plant (W2). The contents of BNPs were set at 0% BNPs (N1) and 5% BNPs (N2). L2W2N2 was used as the control. A total of 12 groups were included in the study. Groups D, E, F, J, K, and L did not use BNPs, while the remaining six groups used 5% BNPs. We found that BNPs exhibit significant aggregation with spherical morphology. As the pH increased, the particle size of BNPs showed a trend of initial increase, followed by a decrease and subsequent increase. Carbon elements existed in three different forms and possessed distinct chemical bonds, resulting in different relative contents. The relative content of C═O accounted for 26.40%, which was significantly higher than that of C—O by approximately 15%. Under the W1 treatment, the height of the tomato plant in L1N2 was 31.7 cm, which is higher by 0.4 cm than that in L1N1. Under L2W1N1 treatment, the net photosynthetic rate, transpiration rate, stomatal conductivity, and intercellular CO2 concentration of tomatoes were 9.68 μmoL ·m2 · s−1, 1.223 mmoL ·m2 · s−1, 0.071 μmoL ·m2 · s−1, and 626 ppm, respectively, which are significantly higher than the control. In conclusion, this research provides a foundation for growing tomatoes.

Morphophysiological comparison of seedlings of Solanum lycopersicum obtained with substrate in tray

The seedbed phase is decisive in the use of quality seedlings for transplanting. This research aimed to evaluate the differentiated vegetative response of tomato cultivars (Solanum lycopersicum L.) to two substrates under tray conditions. The experiment was carried out at the University of Pinar del Río, Cuba. The cultivars 'Celeste', 'Desquite', 'Grandioso' and 'Radiante' were used in a completely randomized design with factorial arrangement (factors: substrate and cultivar). The substrates were made from Fersialitic soil, organic materials (humus or peat) and rice husks. Sowing was carried out in trays with 40 alveoli (tubes), with a capacity for 70 g of substrate each. The substrates used guaranteed adequate morphophysiological development of tomato seedlings, regardless of the cultivar evaluated, although 'Desquite' presented the lowest absolute growth rate. With the use of the substrate based on soil, humus and rice husk, the number of seedlings useful for transplanting increased by 5%, which guarantees a reduction in the number of trays and volume of substrate used in this phase of crop.

Effects of exogenous glycine betaine on growth and development of tomato seedlings under cold stress.

Low temperature is a type of abiotic stress affecting the tomato (Solanum lycopersicum) growth. Understanding the mechanisms and utilization of exogenous substances underlying plant tolerance to cold stress would lay the foundation for improving temperature resilience in this important crop. Our study is aiming to investigate the effect of exogenous glycine betaine (GB) on tomato seedlings to increase tolerance to low temperatures. By treating tomato seedlings with exogenous GB under low temperature stress, we found that 30 mmol/L exogenous GB can significantly improve the cold tolerance of tomato seedlings. Exogenous GB can influence the enzyme activity of antioxidant defense system and ROS levels in tomato leaves. The seedlings with GB treatment presented higher Fv/Fm value and photochemical activity under cold stress compared with the control. Moreover, analysis of high-throughput plant phenotyping of tomato seedlings also supported that exogenous GB can protect the photosynthetic system of tomato seedlings under cold stress. In addition, we proved that exogenous GB significantly increased the content of endogenous abscisic acid (ABA) and decreased endogenous gibberellin (GA) levels, which protected tomatoes from low temperatures. Meanwhile, transcriptional analysis showed that GB regulated the expression of genes involved in antioxidant capacity, calcium signaling, photosynthesis activity, energy metabolism-related and low temperature pathway-related genes in tomato plants. In conclusion, our findings indicated that exogenous GB, as a cryoprotectant, can enhance plant tolerance to low temperature by improving the antioxidant system, photosynthetic system, hormone signaling, and cold response pathway and so on.

Antifungal activity of copper oxide nanoparticles derived from Zizyphus spina leaf extract against Fusarium root rot disease in tomato plants

Incorporating green chemistry concepts into nanotechnology is an important focus area in nanoscience. The demand for green metal oxide nanoparticle production has grown in recent years. The beneficial effects of using nanoparticles in agriculture have already been established. Here, we highlight some potential antifungal properties of Zizyphus spina leaf extract-derived copper oxide nanoparticles (CuO-Zs-NPs), produced with a spherical shape and defined a 13–30 nm particle size. Three different dosages of CuO-Zs-NPs were utilized and showed promising antifungal efficacy in vitro and in vivo against the selected fungal strain of F. solani causes tomato root rot disease, which was molecularly identified with accession number (OP824846). In vivo results indicated that, for all CuO-Zs-NPs concentrations, a significant reduction in Fusarium root rot disease occurred between 72.0 to 88.6% compared to 80.5% disease severity in the infected control. Although treatments with either the chemical fungicide (Kocide 2000) showed a better disease reduction and incidence with (18.33% and 6.67%) values, respectively, than CuO-Zs-NPs at conc. 50 mg/l, however CuO-Zs-NPs at 250 mg/l conc. showed the highest disease reduction (9.17 ± 2.89%) and lowest disease incidence (4.17 ± 3.80%). On the other hand, CuO-Zs-NPs at varied values elevated the beneficial effects of tomato seedling vigor at the initial stages and plant growth development compared to either treatment with the commercial fungicide or Trichoderma Biocide. Additionally, CuO-Zs-NPs treatments introduced beneficial results for tomato seedling development, with a significant increase in chlorophyll pigments and enzymatic activity for CuO-Zs-NPs treatments. Additionally, treatment with low concentrations of CuO-Zs-NPs led to a rise in the number of mature pollen grains compared to the immature ones. however the data showed that CuO-Zs-NPs have a unique antifungal mechanism against F. solani, they subsequently imply that CuO-Zs-NPs might be a useful environmentally friendly controlling agent for the Fusarium root rot disease that affects tomato plants.Graphical

Nickel Ions Enhanced the Adaptability of Tomato Seedling Roots to Low-Nitrogen Stress by Improving Their Antioxidant Capacity

To elucidate the physiological mechanisms underlying the impact of exogenous nickel ions (Ni2+) on the adaptability of tomato (Solanum lycopersicum L.) seedling roots to low-nitrogen levels, the cultivar ‘Micro Tom’ was selected as the experimental material and cultivated hydroponically in the cultivation room of the Fujian Agriculture and Forestry University. Two distinct nitrogen concentrations (7.66 and 0.383 mmol·L−1) and two different levels of Ni2+ (0 and 0.1 mg·L−1 of NiSO4·6H2O) were employed as treatments. On the 9th day of cultivation, we measured the root biomass, the concentrations of antioxidant compounds, and the activities of antioxidant enzymes in the tomato seedlings. The study showed that when the nitrogen levels were low, the growth and development of the tomato seedling roots were hindered. This led to a significant increase in the levels of hydrogen peroxide (H2O2), superoxide anion (O2−), and malondialdehyde (MDA), indicating oxidative damage to the roots. Conversely, treatment with Ni2+ induced a notable increase in the activity of antioxidant enzymes in the seedlings and augmented the accumulation of nonenzymatic antioxidants, such as ascorbic acid (ASA) and reduced glutathione (GSH), thereby enhancing the operational efficiency of the ascorbate–glutathione cycle (ASA–GSH). Consequently, this led to substantial reductions in the H2O2 and MDA levels, ultimately mitigating the oxidative damage inflicted on the tomato seedling roots subjected to low-nitrogen stress. In conclusion, exogenous Ni2+ can reduce the peroxidative damage of tomato seedlings by promoting antioxidase activity in tomato seedlings under low-nitrogen stress, improve the tolerance of tomato seedlings to low-nitrogen stress, and maintain the normal growth and development of tomato seedlings.

Enhancing Drought Tolerance and Fruit Characteristics in Tomato through Exogenous Melatonin Application

Drought stress not only affects the growth and development of tomato seedlings but also leads to a significant decrease in tomato fruit yield. Previous studies have shown that melatonin plays a crucial role in regulating plant tolerance to drought stress. The present study was conducted to investigate the impact of exogenous melatonin on the growth and development of tomato seedlings under drought stress, as well as its potential in improving fruit yield and quality. Our findings demonstrate that drought stress strongly suppressed growth and biomass accumulation, reduced photosynthetic pigments, and inhibited photosynthesis. Conversely, melatonin treatment led to a notable increase in plant height, stem diameter, aboveground biomass, and relative water content of tomato seedlings by 16.67%, 7.39%, 10.58%, and 13.31%, respectively, compared to the drought treatment. Moreover, the chlorophyll content increased by 40.51%, and the net photosynthetic rate increased by 1.2 times. Furthermore, the application of melatonin under drought stress resulted in a decrease in osmoregulation substances, reduced accumulation of reactive oxygen species, and enhanced activity of antioxidant enzymes in tomato seedlings. Exogenous melatonin was also found to inhibit the expression of abscisic-acid-synthesis-related genes, resulting in a reduction in the abscisic acid content in tomato seedlings. Additionally, it significantly increased the root length, root surface area, and root vitality of the plants. When compared to drought treatment, tomato plants treated with melatonin exhibited a 61.92% increase in average yield and a 37.79% increase in fruit weight per plant. Furthermore, the organic acid content decreased by 23.77%, while soluble solids and sugars increased by 15.07% and 35.49%, respectively. These findings suggest that exogenous melatonin effectively alleviates the inhibition of photosynthesis and growth in tomato seedlings under drought stress. It achieves this by regulating the content of osmotic stress substances and the activity of antioxidant enzymes, thus enhancing the resistance of tomato seedlings to drought stress. Moreover, melatonin regulates root growth by mediating the biosynthesis of endogenous ABA, thereby improving the absorption and utilization efficiency of water and nutrients in plants. Consequently, it enhances tomato fruit yield and quality under drought stress.

Effect of Amber (595 nm) Light Supplemented with Narrow Blue (430 nm) Light on Tomato Biomass

Full-spectrum light-emitting diodes (LEDs) mainly comprising 460-nm + 595-nm light are becoming a mainstay in the horticulture industry, and recent studies indicate that plant productivity under white LEDs is higher than combined blue and red LED lighting. Different light properties (wavelength and bandwidth) in full-spectrum light, particularly for the blue and amber light regions, have only partly been explored. This research aimed to characterize the effects of amber + blue light wavelengths and bandwidths on tomato (Solanum lycopersicum cv. Beefsteak) growth, morphology, and production efficiency. Tomato seedlings were subjected to four different light treatments for 60 days: narrow amber light (595 nm), narrow blue + narrow amber light (430 nm + 595 nm) with a 1:10 ratio, white LED (455 nm + 595 nm), and a high-pressure sodium (HPS) lamp (control). The highest mean fresh mass yield occurred with the narrow blue + narrow amber light (479 g), followed by white LED at 20% less, HPS at 34% less, and narrow amber at 40% less. Dry mass and plant height were similar among light treatments. Supplementing narrow amber light with 430-nm blue light led to a 20% increase in chlorophyll content. Findings indicate that narrow amber light is more efficient in biomass accumulation than broad amber light and that precise selection of different blue and amber wavelengths can greatly impact the growth and development of tomato seedlings. This energy-efficient narrow-wavelength combination shows improvement over white LED lighting for maximizing tomato growth.

Influence of Beneficial Bacterial Inoculation on Nitrogen Concentration and Tomato Seedling Growth Under Glasshouse Conditions

Many types of soil bacteria through antagonistic activity, thrive in the rhizosphere of plants or surround the tissues of plants and encourage plant development and reduce the nematode population. Bacteria as such are commonly known as Plant Growth-Promoting Rhizobacteria (PGPR). The purpose of this research was to determine Bacillus spp. inoculations impact on tomato seedling development with varying rates of chemical nitrogen-fertilizer. To minimize the recommended quantity of N fertilizer for tomato seedling development, a small pot experiment with selected PGPB was undertaken with varying amount of N fertilizer. Plant growth-promoting bacteria (PGPB) labeled as UPMB10 and UPMRB9 (identified as Bacillus subtilis and Bacillus tequilensis, respectively) were utilized as microbial inoculants because they showed a significant improvement in seedling growth and N concentration in tomato plant tissues in a pot culture investigation. These microbial inoculants significantly improved the development of the plants, stem length, root length, leaves number, dry weight of shoots (stem, leaves), dry weight of roots, SPAD value, N concentration in tissues, and soil bacterial population. Bacteria-treated seedlings with 50% N fertilizer significantly increased stem length (69.07%), root length (78.51%), leaves number (68.58%), shoots (92.45%, 90.39%, stem and leaves, respectively), roots (73.33%), SPAD value (50.31%), and N concentration in plant tissues (63.79%) as compared to the uninoculated control. The findings also showed that inoculation of the Bacillus spp. tomato seedlings could save up to 50 percent of the recommended rate of chemical N fertilizer without affecting tomato seedling growth. The findings of this study suggest that the amount of nitrogen fertilizer given during tomato seedling development can be reduced by half, resulting in increased soil health and reduced environmental pollution.

Individual and Interactive Ecophysiological Effect of Temperature, Watering Regime and Abscisic Acid on the Growth and Development of Tomato Seedlings

Climate change is a major concern to people all over the world. Most studies have considered singular or dual effects of climate change implications on plant growth and development; however, the combination of multiple factors has received little attention. We therefore studied the single and combined effects of two environmental stress factors (high temperature and water stresses) and abscisic acid on tomato seedlings (Solanum lycoperscum L.). Plants were grown in controlled environment growth chambers under two temperatures (22/18 °C or 28/24 °C; 16 h light/8 h dark), two watering regimes (well-watered or water-stressed), and two abscisic acid treatments (0 and 100 µL of 1mM abscisic acid solution, every other day). Plants were placed under experimental conditions for a total of 33 days, including a 13-day period of initial growth and hardening. Morphological, biochemical, and physiological parameters were measured to assess the growth and development of plants in response to the three factors. ANOVA and Scheffé’s multiple-comparison procedures were used to establish significant differences among treatments and among the three factors being manipulated. All three factors decreased plant height and growth rate. Dry mass accumulation was negatively affected by high temperatures. Transpiration, stomatal conductance, and gas exchange parameters were negatively affected by all three factors; additionally, net carbon dioxide assimilation was reduced by water stress and abscisic acid application. Non-photochemical quenching was decreased in plants grown under higher temperature and in abscisic acid-treated plants. Though it was not significant, abscisic acid appears to mitigate the negative effect of higher temperature and water stress on the nitrogen balance index and total chlorophyll content.

Transcriptome analysis reveals the regulation of cyclic nucleotide-gated ion channels in response to exogenous abscisic acid and calcium treatment under drought stress in tomato.

Background: Drought stress can limit the growth and development of tomato seedlings and cause considerable loss of tomato yield. Exogenous abscisic acid (ABA) and calcium (Ca2+) can effectively alleviate the damage of drought stress to plants in part because Ca2+ acts as a second messenger in the drought resistance pathway. Although cyclic nucleotide-gated ion channels (CNGCs) are common non-specific Ca2+ osmotic channels in cell membranes, a thorough understanding of the transcriptome characteristics of tomato treated with exogenous ABA and Ca2+ under drought stress is necessary to characterize the molecular mechanism of CNGC involved in tomato drought resistance. Results: There were 12,896 differentially expressed genes in tomato under drought stress, as well as 11,406 and 12,502 differentially expressed genes after exogenous ABA and Ca2+ application, respectively. According to functional annotations and reports, the 19 SlCNGC genes related to Ca2+ transport were initially screened, with 11 SlCNGC genes that were upregulated under drought stress and downregulated after exogenous ABA application. After exogenous Ca2+ application, the data showed that two of these genes were upregulated, while nine genes were downregulated. Based on these expression patterns, we predicted the role of SlCNGC genes in the drought resistance pathway and their regulation by exogenous ABA and Ca2+ in tomato. Conclusion: The results of this study provide foundational data for further study of the function of SlCNGC genes and a more comprehensive understanding of drought resistance mechanisms in tomato.

SlMYC2 interacted with the SlTOR promoter and mediated JA signaling to regulate growth and fruit quality in tomato.

Tomato (Solanum lycopersicum) is a major vegetable crop cultivated worldwide. The regulation of tomato growth and fruit quality has long been a popular research topic. MYC2 is a key regulator of the interaction between jasmonic acid (JA) signaling and other signaling pathways, and MYC2 can integrate the interaction between JA signaling and other hormone signals to regulate plant growth and development. TOR signaling is also an essential regulator of plant growth and development. However, it is unclear whether MYC2 can integrate JA signaling and TOR signaling during growth and development in tomato. Here, MeJA treatment and SlMYC2 overexpression inhibited the growth and development of tomato seedlings and photosynthesis, but increased the sugar-acid ratio and the contents of lycopene, carotenoid, soluble sugar, total phenol and flavonoids, indicating that JA signaling inhibited the growth of tomato seedlings and altered fruit quality. When TOR signaling was inhibited by RAP, the JA content increased, and the growth and photosynthesis of tomato seedlings decreased, indicating that TOR signaling positively regulated the growth and development of tomato seedlings. Further yeast one-hybrid assays showed that SlMYC2 could bind directly to the SlTOR promoter. Based on GUS staining analysis, SlMYC2 regulated the transcription of SlTOR, indicating that SlMYC2 mediated the interaction between JA and TOR signaling by acting on the promoter of SlTOR. This study provides a new strategy and some theoretical basis for tomato breeding.

Design and validation of cyanobacteria-rhizobacteria consortia for tomato seedlings growth promotion

The use of rhizobacteria provide great benefits in terms of nitrogen supply, suppression of plant diseases, or production of vitamins and phytohormones that stimulate the plant growth. At the same time, cyanobacteria can photosynthesize, fix nitrogen, synthesize substances that stimulate rhizogenesis, plant aerial growth, or even suppose an extra supply of carbon usable by heterotrophic bacteria, as well as act as biological control agents, give them an enormous value as plant growth promoters. The present study focused on the in vitro establishment of consortia using heterotrophic bacteria and cyanobacteria and the determination of their effectiveness in the development of tomato seedlings. Microbial collection was composed of 3 cyanobacteria (SAB-M612 and SAB-B866 belonging to Nostocaceae Family) and GS (unidentified cyanobacterium) and two phosphate and potassium solubilizing heterotrophic bacteria (Pseudomonas putida-BIO175 and Pantoea cypripedii-BIO175). The results revealed the influence of the culture medium, incubation time and the microbial components of each consortium in determining their success as biofertilizers. In this work, the most compatible consortia were obtained by combining the SAB-B866 and GS cyanobacteria with either of the two heterotrophic bacteria. Cyanobacteria GS promoted the growth of both rhizobacteria in vitro (increasing logarithmic units when they grew together). While Cyanobacteria SAB-B866 together with both rhizobacteria stimulated the growth of tomato seedlings in planta, leading to greater aerial development of the treated seedlings. Parameters such as fresh weight and stem diameter stood out in the plants treated with the consortia (SAB-B866 and both bacteria) compared to the untreated plants, where the values doubled. However, the increase was more discrete for the parameters stem length and number of leaves. These results suggest that the artificial formulation of microbial consortia can have positive synergistic effects on plant growth, which is of enormous agro-biotechnological interest.

Effects of Biochar on the Growth and Development of Tomato Seedlings and on the Response of Tomato Plants to the Infection of Systemic Viral Agents.

Biochar is a rich carbon product obtained by pyrolysis of biomass under a limited supply of oxygen. It is composed mainly of aromatic molecules, but its agronomic value is hard to evaluate and difficult to predict due to its great variable characteristics depending on the type of starting biomass and the conditions of pyrolysis. Anyway, it could be used as soil amendment because it increases the soil fertility of acidic soils, increases the agricultural productivity, and seems to provide protection against some foliar and soilborne diseases. In this study, the effects of biochar, obtained from olive pruning, have been evaluated on tomato seedlings growth and on their response to systemic agents' infection alone or added with beneficial microorganisms (Bacillus spp. and Trichoderma spp.). First, experimental data showed that biochar seems to promote the development of the tomato seedlings, especially at concentrations ranging from 1 to 20% (w/w with peat) without showing any antimicrobial effects on the beneficial soil bacteria at the tomato rhizosphere level and even improving their growth. Thus, those concentrations were used in growing tomato plants experimentally infected with tomato spotted wilt virus (TSWV) and potato spindle tuber viroid (PSTVd). The biochar effect was estimated by evaluating three parameters, namely, symptom expression, number of infected plants, and pathogen quantification, using RT-qPCR technique and −ΔΔCt analysis. Biochar at 10–15% and when added with Trichoderma spp. showed that it reduces the replication of PSTVd and the expression of symptoms even if it was not able to block the start of infection. The results obtained on TSWV-infected plants suggested that biochar could contribute to reducing both infection rate and virus replication. For systemic viral agents, such as PSTVd and TSWV, there are no curative control methods, and therefore, the use of prevention means, as can be assumed the use biochar, for example, in the nursery specialized in horticultural crops, can be of great help. These results can be an encouraging starting point to introduce complex biochar formulates among the sustainable managing strategies of plant systemic diseases.

Melatonin Improves Drought Stress Tolerance of Tomato by Modulating Plant Growth, Root Architecture, Photosynthesis, and Antioxidant Defense System.

Tomato is an important vegetable that is highly sensitive to drought (DR) stress which impairs the development of tomato seedlings. Recently, melatonin (ME) has emerged as a nontoxic, regulatory biomolecule that regulates plant growth and enhances the DR tolerance mechanism in plants. The present study was conducted to examine the defensive role of ME in photosynthesis, root architecture, and the antioxidant enzymes’ activities of tomato seedlings subjected to DR stress. Our results indicated that DR stress strongly suppressed growth and biomass production, inhibited photosynthesis, negatively affected root morphology, and reduced photosynthetic pigments in tomato seedlings. Per contra, soluble sugars, proline, and ROS (reactive oxygen species) were suggested to be improved in seedlings under DR stress. Conversely, ME (100 µM) pretreatment improved the detrimental-effect of DR by restoring chlorophyll content, root architecture, gas exchange parameters and plant growth attributes compared with DR-group only. Moreover, ME supplementation also mitigated the antioxidant enzymes [APX (ascorbate peroxidase), CAT (catalase), DHAR (dehydroascorbate reductase), GST (glutathione S-transferase), GR (glutathione reductase), MDHAR (monodehydroascorbate reductase), POD (peroxidase), and SOD (superoxide dismutase)], non-enzymatic antioxidant [AsA (ascorbate), DHA (dehydroascorbic acid), GSH (glutathione), and GSSG, (oxidized glutathione)] activities, reduced oxidative damage [EL (electrolyte leakage), H2O2 (hydrogen peroxide), MDA (malondialdehyde), and O2•− (superoxide ion)] and osmoregulation (soluble sugars and proline) of tomato seedlings, by regulating gene expression for SOD, CAT, APX, GR, POD, GST, DHAR, and MDHAR. These findings determine that ME pretreatment could efficiently improve the seedlings growth, root characteristics, leaf photosynthesis and antioxidant machinery under DR stress and thereby increasing the seedlings’ adaptability to DR stress.

Respuesta de plántulas de tomate a la aplicación de Trichoderma viride y extracto acuoso de nim

The objective of the research was to evaluate the effect of Trichoderma viride «cepa Ts-3» and aqueous extract of neem seeds (Azadirachta indica A. Juss.) On the growth and development of tomato seedlings (Solanum lycopersicum L. cv. ‘Ulises’). The experiment was carried out at the University of Pinar del Río, Cuba. Four treatments were established: control (seedlings without inoculations), seedlings + T. viride, seedlings + neem and seedlings + T. viride + nim, distributed in a completely random design, under conditions of trays and substrate based on Ferralitic Yellowish soil (70%), peat (20%) and rice husk (10%). Biostimulant activity of T. viride «cepa Ts-3» was found on the fresh root mass of the seedlings of tomato cv. ‘Ulises’; while the application of the aqueous extract of neem seeds negatively affected the growth and vegetative development of this cultivar, with a reduction of more than 40% of the fresh and dry biomass, although its inhibitory effect decreased in seedlings inoculated with T. viride «cepa Ts-3». The multivariate analysis allowed to differentiate the seedlings treated only with extract from those obtained in the other treatments and showed the possibility of combining the use of the agroecological alternatives evaluated.

Biostimulants in the development of tomato and collard greens seedlings

The success of crop yields begins with the use of quality seedlings. Crops from vigorous plants respond better to phytosanitary treatments and management techniques, resulting in economic returns and better use of inputs. The objective of this study was to evaluate NPK fertilizer rates and rates of an NPK + auxin biostimulant on the effects over agronomic features of Collard Greens and salad tomato seedlings. The research consisted of two experiments in randomized block, with four replications each. Both experiments were in factorial scheme 2 x 4, consisting of the combination of two nutrient sources (NPK fertilizer 9-45-11 and biostimulant composed of NPK 9-45-11 + 400 mg kg -1 of auxin IAA), and four rates, being then 50; 100; 150 and 200% of the recommended rate of biostimulant for tomato and 50; 75; 100 and 125% of the recommended rate for Collard Greens. The biostimulant favored the development of tomato seedlings, since it provides greater root dry mass accumulation and didn’t promote seedling shedding, as it occurred in the application of NPK fertilizers. On the other hand, the Collard Greens seedlings didn’t distinguish by the presence of auxin in the biostimulant, developing greater seedlings heights with NPK application. Concentrations of 50-200% of the recommended biostimulant fertilizer didn’t interfere on root length, diameter and root dry mass of Collard Greens.

Production of tomato seedlings using seeds pelleted with Natrum muriaticum and submitted to saline stress

The development and yield of plants is directly related to the effects of salinity. There are several reports in scientific studies of significant reduction in the growth and production of tomato in soils with high electrical conductivity. The correction or recovery of salinized soils, although technically possible, is a slow and very expensive process, making it necessary to develop new technologies. The objective of this study is to evaluate the production of tomato (Solanum lycopersicon L.) seedlings using seeds pelleted with a homeopathic preparation of Natrum muriaticum (Nat-m) submitted to saline stress. The treatments consisted of the pelletization of tomato seeds with six dynamizations of Nat-m (3cH, 5cH, 7cH, 9cH, 11cH and 13cH). Coated or uncoated seeds (controls) were placed in phenolic foam blocks, kept in plastic trays previously moistened with 50 mM NaCl saline solution (2.922 g.L-1 of NaCl, electrical conductivity = 4.5 dSm-1) and nutrient solution (0.15 dS.m-1) at half the ionic strength, containing 4, 1, 2, 1, 0.5 and 0.5 mmol.L-1 of N, P, K, Ca, Mg and S, and 17.5, 9.5, 10.5, 2, 0.45 and 0.35 mmol.L-1 of Fe, Mn, Zn, Cu and Mo, respectively. The variables evaluated were germination percentage, germination speed index, shoot length, leaf area, number of leaves, root volume, root dry matter, and shoot dry matter. The treatments pelleted seeds/talc Nat-m 5cH and pelleted seeds/talc Nat-m 7cH increased all variables evaluated. They differed statistically from the controls, with a positive response for the development of tomato seedlings under disequilibrium conditions.

Comparative Genomic and Physiological Analyses of a Superoxide Dismutase Mimetic (SODm-123) for Its Ability to Respond to Oxidative Stress in Tomato Plants.

Superoxide dismutases (SODs) are a group of enzymes that have a crucial role in controlling oxidative stress in plants. Here, we synthesized an environmentally friendly SOD mimic, SODm-123, from L-aspartic acid and manganese oxide. SODm-123 showed similar enzymatic activity to Mn-SOD. To gain insights into the role of SODm-123 in oxidative stress tolerance, a series of experiments were conducted to assess the physiological and molecular responses of tomato plants when treated with SODm-123. The results showed that the levels of O2-• and H2O2 in tomato cells were affected by SODm-123 treatment, indicating that SODm-123 can control oxidative stress like Mn-SOD. The results also exhibited that SODm-123 increased the contents of photosynthetic pigments. However, it was noted that SODm-123 resulted in a reduction in the content of soluble sugar and MDA. These results indicate that SODm-123 promoted the efficiency of photosynthesis by regulating the content of H2O2. To further investigate the role of SODm-123 in controlling oxidative stress, a transcriptome analysis was used to identify differentially expressed genes (DEGs) associated with SODm-123 treatment. The results indicated that SODm-123 treatment resulted in 341 differentially expressed genes (DEGs) in treated tomato leaves at 96 h after treatment. Kyoto encyclopedia of genes and genomes (KEGG) revealed that DEGs were involved in pathways such as photosynthetic pigment biosynthesis, ABC transporters, sugar metabolism, and MAPK signaling, which further confirmed a positive role of SODm-123 in improving stress tolerance in plants. Overall, the results of this study suggest that SODm-123 promotes the growth and development of tomato seedlings and therefore can be used as a potential growth-promoting agent for plants.

Antioxidant potential and iodine accumulation in tomato (Solanum lycopersicum L.) seedlings as the effect of the application of three different iodobenzoates

Abstract Iodine (I) has a beneficial effect on plant growth, development and antioxidant activity. The study aimed to compare iodine uptake after the application of iodobenzoates (2-iodobenzoic acid (2-IBeA), 4-iodobenzoic acid (4-IBeA) and 2,3,5-triiodobenzoic acid (2,3,5-triIBeA)) as well as potassium iodide (KI) to tomato seedlings. One of the main tasks was to evaluate how the tested compounds applied in different concentrations (5, 10, 25 and 50 μM) affect the growth and antioxidative potential of tomato seedlings. Negative effect on growth and development of tomato seedlings was noted for 4-IBeA applied in 10–50 μM I concentrations. The 2,3,5-triIBeA application affected shoot deformation. All tested iodine compounds increased iodine level in leaves and roots of tomato seedlings. Iodine after KI application was accumulated mainly in leaves, while after iodobenzoates treatment in roots of tomato seedlings, which is probably related to their weaker transport to the upper parts of the plant. Tested compounds variously modified the content of ascorbic and dehydroascorbic acids in tomato leaves depending on applied concentration. KI treatment improved ascorbate peroxidase activity, but all iodobenzoates decreased APX and catalase activity in leaves. 4-IBeA (5 μM I) and 2,3,5-triIBeA (25 and 50 μM I) increased guaiacol peroxidase activity in leaves. It can be concluded that mechanisms responsible for plant oxidative metabolism were variously affected by the iodine compounds and its concentration in the nutrient solution.

The effect of vermicomposts on tomato productivity in the conditions of Yakutia

The article presents the research results of the effect of vermicompost based on horse and cattle manure on the productivity of tomatoes in Yakutia. The conducted experiments have established that only half of the manure (50%) is converted into biohumus from all processed raw materials. Fertilizing with the obtained vermicompost helps to improve the properties of greenhouse soil mixtures. It was found that fertilizers help to optimize the physical properties of soils, while increasing the microbiological activity in the soil. The vermicompost derived from horse manure in the composition of greenhouse fertile soils contributed to better development of tomato seedlings. When fertilizing with the vermicompost the best development of seedlings up to 10-30% is noted. Further increase of biofertilizers application inhibits the development of plants, reducing their biometric indicators. The experiment also studied the effect of increasing doses of vermicompost from 100 to 500 g / plant when applied locally. The efficiency of the lowest application dose of vermicompost 100 g / plant (6.2 kg / m2), which corresponds to increasing tomato productivity by 8.8%. Further increase in the rate of biofertilizers does not give a significant increase in productivity. Thus, it justifies the vermicompost application for the enrichment of the greenhouse soil and increasing tomato productivity in conditions of Yakutia.