Parts Of Tomato Plants Research Articles

Biostimulant and antagonistic potential of endophytic fungi against fusarium wilt pathogen of tomato Fusarium oxysporum f. sp. lycopersici

Endophytic fungal-based biopesticides are sustainable and ecologically-friendly biocontrol agents of several pests and diseases. However, their potential in managing tomato fusarium wilt disease (FWD) remains unexploited. This study therefore evaluated effectiveness of nine fungal isolates against tomato fusarium wilt pathogen, Fusarium oxysporum f. sp. lycopersici (FOL) in vitro using dual culture and co-culture assays. The efficacy of three potent endophytes that inhibited the pathogen in vitro was assessed against FWD incidence, severity, and ability to enhance growth and yield of tomatoes in planta. The ability of endophytically-colonized tomato (Solanum lycopersicum L.) plants to systemically defend themselves upon exposure to FOL were also assessed through defence genes expression using qPCR. In vitro assays showed that endophytes inhibited and suppressed FOL mycelial growth better than entomopathogenic fungi (EPF). Endophytes Trichoderma asperellum M2RT4, Hypocrea lixii F3ST1, Trichoderma harzianum KF2R41, and Trichoderma atroviride ICIPE 710 had the highest (68.84–99.61%) suppression and FOL radial growth inhibition rates compared to EPF which exhibited lowest (27.05–40.63%) inhibition rates. Endophytes T. asperellum M2RT4, H. lixii F3ST1 and T. harzianum KF2R41 colonized all tomato plant parts. During the in planta experiment, endophytically-colonized and FOL-infected tomato plants showed significant reduction of FWD incidence and severity compared to non-inoculated plants. In addition, these endophytes contributed to improved growth promotion parameters and yield. Moreover, there was significantly higher expression of tomato defence genes in T. asperellum M2RT4 colonized than in un-inoculated tomato plants. These findings demonstrated that H. lixii F3ST1 and T. asperellum M2RT4 are effective biocontrol agents against FWD and could sustainably mitigate tomato yield losses associated with fusarium wilt.

Zoophytophagous predator sex pheromone and visual cues of opposing reflectance spectra lure predator and invasive prey.

In sub-Saharan Africa, the invasive South American leafminer Phthorimaea absoluta is the most damaging tomato pest. Females of the pest can reproduce both sexually and through parthenogenesis and lay their eggs on all tomato plant parts. The mirid predator Nesidiocoris tenuis, a biological control agent for the pest, is also a tomato pest when prey population is low. To date, however, no study has developed an eco-friendly solution that targets both the predator and its host in a tomato farming system. To develop a bio-based management system for both pest and predator based on the combined use of sexual communication in the predator and visual cues. We collected volatiles from both sexes of the Kenyan population of the predator N. tenuis and identified candidate sex pheromone components by coupled gas chromatography-mass spectrometry (GC-MS). We used electrophysiological assays to identify antennally-active odorants in the volatiles, followed by field trials with different pheromone-baited colored traps to validate the responses of both predator and prey. Thereafter, we compared the reflectance spectra of the colored traps with those of different tomato plant tissues. Our results reveal an interplay between different sensory cues which in the predator-prey interaction may favor the predator. Antennae of both sexes of predator and prey detect the predator sex pheromone identified as 1-octanol and hexyl hexanoate. Unexpectedly, our field experiments led to the discovery of a lure for P. absoluta females, which were lured distinctly into a pheromone-baited trap whose reflectance spectrum mimicked that of ripe tomato fruit (long wavelength), an egg-laying site for females. Contrastingly, N. tenuis males were lured into baited white trap (short wavelength) when the predator is actively searching for prey. Our results demonstrate the novel use of a predator sex pheromone and different visual cues to assess complex trophic interactions on tomatoes.

Fermented botanical fertilizer controls bacterial wilt of tomatoes caused by Ralstonia pseudosolanacearum.

This study demonstrates the effect of fermented botanical product (FBP) on Ralstonia pseudosolanacearum-induced bacterial wilt disease and unravels its action mechanism. Soaking with diluted FBP solutions (0.1%-0.5%) significantly suppressed bacterial wilt in tomato plants, and FBP-treated tomato plants grew well against R. pseudosolanacearum infection. Growth assays showed that FBP had no antibacterial effect but promoted R. pseudosolanacearum growth. In contrast, few or no R. pseudosolanacearum cells were detected in aerial parts of tomato plants grown in FBP-soaked soil. Subsequent infection assays using the chemotaxis-deficient mutant (ΔcheA) or the root-dip inoculation method revealed that FBP does not affect pathogen migration to plant roots during infection. Moreover, FBP-pretreated tomato plants exhibited reduced bacterial wilt in the absence of FBP. These findings suggest that the plant, but not the pathogen, could be affected by FBP, resulting in an induced resistance against R. pseudosolanacearum, leading to a suppressive effect on bacterial wilt.

3D data-augmentation methods for semantic segmentation of tomato plant parts.

3D semantic segmentation of plant point clouds is an important step towards automatic plant phenotyping and crop modeling. Since traditional hand-designed methods for point-cloud processing face challenges in generalisation, current methods are based on deep neural network that learn to perform the 3D segmentation based on training data. However, these methods require a large annotated training set to perform well. Especially for 3D semantic segmentation, the collection of training data is highly labour intensitive and time consuming. Data augmentation has been shown to improve training on small training sets. However, it is unclear which data-augmentation methods are effective for 3D plant-part segmentation. In the proposed work, five novel data-augmentation methods (global cropping, brightness adjustment, leaf translation, leaf rotation, and leaf crossover) were proposed and compared to five existing methods (online down sampling, global jittering, global scaling, global rotation, and global translation). The methods were applied to PointNet++ for 3D semantic segmentation of the point clouds of three cultivars of tomato plants (Merlice, Brioso, and Gardener Delight). The point clouds were segmented into soil base, stick, stemwork, and other bio-structures. Among the data augmentation methods being proposed in this paper, leaf crossover indicated the most promising result which outperformed the existing ones. Leaf rotation (around Z axis), leaf translation, and cropping also performed well on the 3D tomato plant point clouds, which outperformed most of the existing work apart from global jittering. The proposed 3D data augmentation approaches significantly improve the overfitting caused by the limited training data. The improved plant-part segmentation further enables a more accurate reconstruction of the plant architecture.

Accumulation and metabolism of pyroxasulfone in tomato seedlings

Pyroxasulfone (PYS) is an isoxazole herbicide favored for its high activity. However, the metabolic mechanism of PYS in tomato plants and the response mechanism of tomato to PYS are still lacking. In this study, it was found that tomato seedlings had a strong ability to absorb and translocate PYS from roots to shoots. The highest accumulation of PYS was in the apex tissue of the tomato shoots. Using UPLC-MS/MS, five metabolites of PYS were detected and identified in tomato plants, and their relative contents in different parts of tomato plants varied greatly. The serine conjugate, DMIT [5, 5-dimethyl-4, 5-dihydroisoxazole-3-thiol (DMIT)] &Ser, was the most abundant metabolites of PYS in tomato plants. In tomato plants, the conjugation of thiol-containing metabolic intermediates of PYS to serine may mimic the cystathionine β-synthase-catalyzed condensation of serine and homocysteine (in the pathway sly00260 sourced from KEGG database). This study ground breakingly proposed that serine may play an important role in plant metabolism of PYS and fluensulfone (whose molecular structure is similar to PYS). PYS and atrazine (whose toxicity profile is similar to PYS but not conjugate with serine) produced different regulatory outcomes for endogenous compounds in the pathway sly00260. Differential metabolites in tomato leaves exposed to PYS compared with the control, including amino acids, phosphates, and flavonoids, may play important roles in tomato response to PYS stress. This study provides inspiration for the biotransformation of sulfonyl-containing pesticides, antibiotics and other compounds in plants.

UPTAKE AND DISTRIBUTION OF RADIOSTRONTIUM IN TOMATO TREATED WITH ARBUSCULAR MYCORRHIZAL FUNGI.

Arbuscular mycorrhizal fungi (AMF) were inoculated into the root system of edible tomato plants to investigate their effect on the uptake and distribution of strontium radionuclide in the tissues of plants grown under laboratory conditions. The experiments were carried out in a sterile mixture of topsoil and sand, where in one series of experiments contaminated soil with 85Sr was used. Seeds were inoculated with a mixture of AMF at sowing, the second, control series was without application of AMF. Determination of radioactivity in soil and in different parts of tomato plants was carried out by gamma-spectrometric measurement. The obtained results and statistical analysis indicated a significant association between AMF inoculation of plants and the change in the distribution of 85Sr. The presence of AMF reduced the translocation of 85Sr from the root system to the aerial parts of tomato plants.

First Report of Xanthomonas euvesicatoria Causing Bacterial Spot Disease in Tomato in Blue Nile State, Sudan

Bacterial spot caused by Xanthomonas vesicatoria is considered to be a major constraint of tomato production all over the world in particular warmer and humid parts.A disease disorder was reported in autumn season 2015within the Blue Nile State in Sudanaffecting all aerial parts of tomato plant. Symptomatic tomato leaves were collected and sent toPlant Pathology Laboratory, Faculty of Agriculture, University of Khartoum. An investigation on whether a phytopathogen was associated with symptoms of bacterial spots damage on tomato was conducted.The pathogen wasisolated and characterized morphologically, biochemically and at molecular level. The bacterium wasidentified as Xanthomonaseuvesicatoria and confirmed by PCR and sequence analysis of the 16S RNA gene (GenBankAccession Nos MH047248, MH051263 and MG686236).The disease incidence was remarkably high in ALrosserisand Aldamazein which recorded 49.27 and 52.17%, respectively, while the disease severity was 28.28 and 30.32%, respectively. To our knowledge, this is the first report of Xanthomonaseuvesicatoria causing bacterial spot disease in tomato in Sudan.

Role of Na+ transporters HKT1;1 and HKT1;2 in tomato salt tolerance. I. Function loss of cheesmaniae alleles in roots and aerial parts

We analyzed the physiological impact of function loss on cheesmaniae alleles at the HKT1;1 and HKT1;2 loci in the roots and aerial parts of tomato plants in order to determine the relative contributions of each locus in the different tissues to plant Na+/K+ homeostasis and subsequently to tomato salt tolerance. We generated different reciprocal rootstock/scion combinations with non-silenced, single RNAi-silenced lines for ScHKT1;1 and ScHKT1;2, as well as a silenced line at both loci from a near isogenic line (NIL14), homozygous for the Solanum cheesmaniae haplotype containing both HKT1 loci and subjected to salinity under natural greenhouse conditions. Our results show that salt treatment reduced vegetative growth and altered the Na+/K+ ratio in leaves and flowers; negatively affecting fruit production, particularly in graft combinations containing single silenced ScHKT1;2- and double silenced ScHKT1;1/ScHKT1;2 lines when used as scion. We concluded that the removal of Na+ from the xylem by ScHKT1;2 in the aerial part of the plant can have an even greater impact than that on Na+ homeostasis at the root level under saline conditions. Also, ScHKT1;1 function loss in rootstock greatly reduced the Na+/K+ ratio in leaf and flower tissues, minimized yield loss under salinity. Our results suggest that, in addition to xylem Na+ unloading, ScHKT1;2 could also be involved in Na+ uploading into the phloem, thus promoting Na+ recirculation from aerial parts to the roots. This recirculation of Na+ to the roots through the phloem could be further favoured by ScHKT1;1 silencing at these roots.

Synthesis of urea slow-release fertilizer using a novel starch-g-poly(styrene-co-butylacrylate) nanocomposite latex and its impact on a model crop production in greenhouse

Herein, an innovative slow-release fertilizers (SRFs) were developed using a bio-based and waterborne polymeric coating containing starch-g-poly(styrene-co-butylacrylate) latex reinforced with natural char nanoparticles (NCNPs). Several SRF samples were prepared via coating the urea granules with the latex formulations containing different amounts of NCNPs, and their urea release rates were evaluated. The results showed that the presence of NCNPs nano-filler and decreasing the temperature could prolong the urea release time. The performances of the SRF samples were compared to urea granules and a commercial latex coating (SBR, poly(styrene-co-butyl acrylate)) on tomato production in the greenhouse. The results confirmed that NCNPs in coating formulation played an important role in improving plant growth and reducing N-release rate. The efficiencies of all the synthesized SRF samples were higher than the SBR-coated urea confirming the key-role of starch in the coating formulations. In sample containing 1 w% NCNPS (F13), total nitrogen percentage and nitrate content in the aerial parts of tomato plants were increased (21.1%) and decreased (42.1%) compared to the pristine urea, respectively. Particularly, application of F13 formulation could enhance the nitrogen use efficiency (NUE), nitrogen agronomic efficiency (NAE), and nitrogen apparent recovery fraction (NRF), 68.3%, 49.9%, and 29.7%, compared to the urea granules, respectively.

Antimicrobial properties of tomato leaves, stems, and fruit and their relationship to chemical composition

BackgroundWe previously reported that the tomato glycoalkaloid tomatine inhibited the growth of Trichomonas vaginalis strain G3, Tritrichomonas foetus strain D1, and Tritrichomonas foetus-like strain C1 that cause disease in humans and farm and domesticated animals. The increasing prevalence of antibiotic resistance requires development of new tools to enhance or replace medicinal antibiotics.MethodsWild tomato plants were harvested and divided into leaves, stems, and fruit of different colors: green, yellow, and red. Samples were freeze dried and ground with a handheld mill. The resulting powders were evaluated for their potential anti-microbial effects on protozoan parasites, bacteria, and fungi. A concentration of 0.02% (w/v) was used for the inhibition of protozoan parasites. A high concentration of 10% (w/v) solution was tested for bacteria and fungi as an initial screen to evaluate potential anti-microbial activity and results using this high concentration limits its clinical relevance.ResultsNatural powders derived from various parts of tomato plants were all effective in inhibiting the growth of the three trichomonads to varying degrees. Test samples from leaves, stems, and immature ‘green’ tomato peels and fruit, all containing tomatine, were more effective as an inhibitor of the D1 strain than those prepared from yellow and red tomato peels which lack tomatine. Chlorogenic acid and quercetin glycosides were present in all parts of the plant and fruit, while caffeic acid was only found in the fruit peels. Any correlation between plant components and inhibition of the G3 and C1 strains was not apparent, although all the powders were variably effective. Tomato leaf was the most effective powder in all strains, and was also the highest in tomatine. S. enterica showed a minor susceptibility while B. cereus and C. albicans fungi both showed a significant growth inhibition with some of the test powders. The powders inhibited growth of the pathogens without affecting beneficial lactobacilli found in the normal flora of the vagina.ConclusionsThe results suggest that powders prepared from tomato leaves, stems, and green tomato peels and to a lesser extent from peels from yellow and red tomatoes offer potential multiple health benefits against infections caused by pathogenic protozoa, bacteria, and fungi, without affecting beneficial lactobacilli that also reside in the normal flora of the vagina.

English

The current research was conducted to investigate the alterations in the mineral status in the leaves of tomato plants against early blight (EB) caused by Alternaria solani. Six tomato varieties; viz. Riograndae, Roma and Basket (resistant) and T-88572, BHN-961 and BHN-1021(susceptible) were inoculated with a blend of five isolates of Alternaria solani, collected from different regions of Faisalabad District. These six varieties for mineral profiling were selected after two years screening from twenty-five varieties of tomatoes under field conditions. These varieties were sown in pots and artificial inoculation was performed to develop disease in inoculated type of tomato plants while distilled water was applied on un-inoculated type of plants. Newly infected leaves from upper, middle and lower parts of tomato plants from resistant and susceptible groups were used to prepare sample for mineral analysis at p ≤ 0.05 and variation in mineral profiling of resistant and susceptible groups of tomato plants was determined through Nested Structured Design. Significant variation was observed in inoculated (3.12, 0.48 %, 1.17, 0.14, 0.42, 0.21, 0.69 and 1.49 ppm and un-inoculated type (8.67, 1.61%, 10.45, 0.22, 1.75, 1.98, 3.09 and 3.39 ppm) while resistant group expressed 6.59, 1.19%, 8.13, 1.973, 1.69, 1.26, 1.36, 2.43 and 2.87ppm and susceptible group exhibited 5.19, 0.91%, 5.69, 1.693, 1.24, 0.91,0.83, 1.35 and 2.22 ppm with respect to NPK, Ca, Mg, Na, Zn, Iron and copper. Resistant variety, Riograndae expressed maximum amount while T-88572 exhibited minimum amount of all mineral contents. Alterations in the mineral profiling in leaves of tomato plants can be used by researchers as biochemical markers for identification and development of resistant source against early blight of tomato and for the development of ecofriendly management strategy towards A. solani.

Türkiye’de Domates Seralarında Kurşuni Küf (Botrytis cinerea) Hastalığının Boscalid ve Pyraclostrobin’e Karşı Fungisit Dayanıklılığının Değerlendirilmesi

Botrytis cinerea, a polyphagous pathogen, can infect all of the aboveground parts of tomato plants and cause significant yield and quality losses. Fungicides are commonly used for the control of this pathogen. Currently, resistance to fungicides, which provide the effective and fast control of pathogens, is an important problem. In this study, resistance of B. cinerea isolates obtained from tomato greenhouses in Antalya province against Signum® (boscalid + pyraclostrobin) and Cantus® (boscalid) fungicides were evaluated under in vitro conditions. Mycelium growth tests conducted with different fungicide concentrations and EC50 values were calculated. While EC50 values of isolates sensitive to boscalid varied between 0.7 and 8.6 μg/ml, EC50 values of isolates sensitive to boscalid + pyraclostrobin were found to be between 0.1 and 1.9 μg/ml. Conidial germination tests were carried out in a 2% water agar (WA) medium. It was determined that isolates 61, 69, 72, and 81 were resistant to both fungicides, while isolates 57 and 97 were sensitive to boscalid and resistant to boscalid + pyraclostrobin. It has been determined that 20% of the isolates were resistant to both fungicides. Isolates resistant to boscalid but sensitive to boscalid+pyraclostrobin were not found. With this current in vitro study, the first data on the resistance formation against boscalid and boscalid + pyraclostrobin active ingredients in B. cinerea populations in Antalya province were presented. There is a need to develop integrated control programs that can be used in the control of the pathogen.

Molecular identification of <i>Helicoverpa armigera</i> (Hubner) associated with tomatoes (<i>Solanum lycopersicum L.</i>) in Ogun State

The tomato fruit worm Helicoverpa armigera is a key polyphagous agricultural pest with a worldwide distribution. Apart from tomatoes, H. armigera also infests cotton, maize, chickpea and pigeon-pea. Its larvae affect almost all the aerial parts of tomato plants from the vegetative stage to the fruit maturation stage. Due to its high mobility, it causes a huge damage on crops and, as such, early detection of H. armigera from different agro-ecosystems is crucial for implementing control measures. Herein, we used a molecular marker approach to identify Helicoverpa spp. collected from twelve different locations in Ogun State. The H. armigera larvae used for the molecular identification were collected on tomato fruits from the 12 different locations from three agro-ecological zones in Ogun State. Genomic DNA of Helicoverpa was extracted and its purity was checked using Nanodrop spectrophotometer. Cytochrome Oxidase-I (CO-I) region of the DNA was subjected to Polymerase Chain Reaction (PCR) amplification. The PCR amplification of the CO-I gene after gel electrophoresis of PCR products of H. armigera showed a similar banding pattern at 700 base pairs which confirmed the insect as H. armigera.
 Keywords: Helicoverpa armigera, Deoxyribonucleic acid, Cytochrome Oxidase-I, Polymerase Chain Reaction, Electrophoresis.

Occurrence of heavy metals and pesticide residues in tomato crop: a threat to public health

The presence of heavy metals and pesticide residues in higher concentrations in irrigation water and crops are two major concerns in developing and underdeveloped countries. The assessment and monitoring of these environmental contaminants in fruit and vegetables are vital for effective management and consumers’ health. In the current study, the presence of heavy metals and pesticides in irrigation water (sewage and tube well), soil, and tomato crop (grown on these water sources and sprayed with different pesticides in various locations of Peshawar city) was determined. Sewage water exhibited a significantly (p > 0.05) higher pH, total dissolved solid (TDS), and electrical conductivity (EC) when compared with the optimum limits as recommended by the World Health Organization (WHO). In addition, the concentrations of heavy metals, i.e., Cd, Pb, Ni, Cu, Zn, and Fe, were also significantly (p > 0.05) higher in this source. Furthermore, the analysis of sewage irrigated soil and various parts of tomato plants grown on this soil revealed a higher concentration of heavy metals compared with the standard limit set by WHO. Similarly, the levels of pesticide residues of chlorpyrifos and emamectin were significantly (p > 0.05) higher in tomato fruits and leaves and soil samples when compared with the standard limits set by the European Union. The current study provides first ever insight into the presence and levels of toxic heavy metals and pesticide residues in tomato crops grown on sewage water in Peshawar city for the effective monitoring and management of these health hazards.

Effect of Irrigation Water Containing Iodine on Plant Physiological Processes and Elemental Concentrations of Cabbage (Brassica oleracea L. var. capitata L.) and Tomato (Solanum lycopersicum L.) Cultivated in Different Soils

Iodine uptake and translocation was studied in cabbage and tomato cultivated on different soil types (sand, sandy silt, silt) by applying irrigation water containing iodine at concentrations of 0.1 and 0.5 mg/L. Iodine treatment at the concentrations applied did not significantly influence the photosynthetic efficiency and chlorophyll concentration of cabbage and tomato leaves. The growth of cabbage leaves cultivated on sand and sandy silt soil with iodine treatment was slightly stimulated, while, on silt soil, it remained unchanged; for tomato plant parts, independent of the soil-type, the dry mass values remained constant. It can be concluded that iodine treatment had no negative effect on the physiological characteristic of cabbage and tomato plants. Applying 0.5 mg/L in the irrigation water, the highest biofortification with iodine was achieved in plants cultivated in sandy soil and the iodine concentration calculated in the dry matter amounted to 10 and 3.6 mg/kg in the leaves and fruits of cabbage and tomato, respectively. Considering the iodine and moisture content of cabbage leaves and tomato fruits, the consumption of 100 g of fresh vegetable would cover about 80% and 15% of the recommended iodine intake, respectively. The presence of iodine resulted in a reduction in Fe and P concentrations in tomato fruits independent of the soil-type; however, the concentration of Mg, Cu, Mn, Zn, and B remained practically unchanged. However, for cabbage, no similar trend for Fe and P was observed.

Effect of Trichoderma harzianum on morpho-physiological parameters and metal uptake of tomato plants

In this study we have investigated the effect of T. harzianum on growth, content of chlorophyll and epidermal flavonols and metal distribution in tomato plants. Trichoderma strain, isolated from the A horizon (5-30 cm) of agricultural soil used in organic production, was applied near the root in the sixth leaf development phase of tomato. Tomato plants were grown in a growth cabinet up to the stage of 10 leaves. Content of chlorophyll (Chl), epidermal flavonols (Flav) and antocyanins (Ant) were measured in vivo non-destructively. The concentration of Cd, Co, Cu, Cr, Fe, Mn, Ni, Se, and Zn was measured in different parts of tomato plants by ICP-OES method. Results have shown that Trichoderma application positively affected growth of tomato plants, and significantly decreased nitrogen balance index. In Trichoderma treated plants the contents of Cr and Ni were significantly reduced in roots, while content of Cd tended to decrease in all plant parts, significantly in roots. Presented results indicate that investigated isolate is worthwhile testing for plant growth promotion in field conditions, taking in account different supply of macro and micronutrients.

Changes in Secondary Metabolites and Free Amino Acid Content in Tomato with <i>Lamiaceae</i> Herbs Companion Planting

The present experiment was conducted to evaluate the influence of Lamiaceae herbs companion planting on growth and secondary metabolites changes in tomato plants. Furthermore, the free amino acid changes in tomato due to companion planting were also evaluated using tomato-basil companionship as a model. Four-week-old seedlings of tomato were grown in a pot containing autoclaved commercial soil with basil, peppermint and hyssop as a companion plant separately in different density. Four weeks after companion planting, tomato plants under 1:1 companionship with the herbs showed significant increase in dry weights of shoots compared to control. Higher density of the herbs on the other hand expressed a growth suppression on tomato possibly due to nutrient competition. By the LC-MS analysis, shikimic acid and apigenin were identified as the major secondary compounds found in tomato plants and 1:1 companionship with basil seemed to have a positive influence on their content in tomato shoots. On the other hand, in case of peppermint and hyssop, the increase was observed in all parts of tomato plants. In addition, promotion in several free amino acid contents was also observed in tomato plants with basil companion planting compared to control. Thus, tomato plants grown with herb companion planting in 1:1 ratio seems to have a positive impact on growth of tomato. This positive influence might be related to the increase in some secondary metabolites and changes in the free amino acids observed in this study.

Sewage sludge land application: Balancing act between agronomic benefits and environmental concerns

Land disposal of sewage sludge has become an attractive practice worldwide. However, ubiquitous presence of toxic metals raises environmental and public health concerns regarding subsequent plant uptake. This study was intended to determine the suitability of sewage sludge application under hot environmental condition using tomato crop. A greenhouse experiment was conducted to investigate various levels of heavy metals as well as potential health risks associated with the consumption of tomato fruit grown in sludge amended soil. Plant samples were collected on four different growth stages: beginning of the experiment before planting, twice during growing period, and at the end of the experiment (post-harvest). Samples were analyzed for commonly occurring heavy metal contaminants (Cd, Cr, Cu, Pb and Zn). In this study, we did not observe consistent relationship between metal concentrations in tomato plant and various sludge ratio. Heavy metal levels were consistently greater in roots than other parts of tomato plant, followed by stem. The most salient finding from our study was that Cd and Pb, two very important metals because of their solubility and subsequent mobility, were not detectable in tomato fruits under any of the sludge treatments, compared to other parts of tomato plants. The trend in transfer factors (TF) followed the sequence Zn > Cu > Cr > Cd for roots and Zn > Cu > Cr for fruits, suggesting the risk of heavy metal TF to tomato fruits is minimal. It can be inferred from these results that potential risk may be greater through consumption of leafy vegetables and tuber crops.

Antimicrobial Activity of Various Parts of Tomato Plants Varied with Different Solvent Extracts.

The antimicrobial activity of acetone, hexane, dichloromethane, and methanol extracts from leaves, stems, immature green fruits, and red fruits of tomato plants was examined against six phytopathogens. The minimum inhibitory concentration (MIC) of the acetonic extracts from these four plant parts was lower than that of the other solvents. Among the acetonic extracts, tomato leaves had a lower MIC than the other tomato parts. The acetonic extract from tomato leaves was therefore selected as a source of antimicrobial substances. The acetonic extract from tomato leaves inhibited mycelial growth of Fusarium oxysporum f. sp. lycopersici, Glomerella cingulata, and Rhizoctonia solani. Mycelial growth of R. solani treated with acetone extract from leaves showed more susceptibility than the other phytopathogens. Using 0.31 mg/ml of the acetonic extract from leaves, mycelial growth of R. solani on days 1, 2, and 3 decreased by 50.0, 52.1, and 64.0%, respectively, compared with acetone solvent treatment. The antimicrobial compounds effective against R. solani were identified as linolenic acid and caffeic acid by bioautography and GC-MS. These two compounds were used to treat six phytopathogens to confirm their antimicrobial activities. Linolenic acid inhibited mycelial growth of R. solani, while caffeic acid showed only slight antimicrobial activity. Results indicated that we propose extracts from tomato leaves which included antimicrobial compounds may provide a new lead in the pursuit of new biological sources of agrochemical candidates.

Comparison of Rhodanese Activity and Distribution in Tomato (Solanum lycopersicum Mill.) Plant Parts and its Physicochemical Characterization

Tomato (Solanum lycopersicum Mill.) which belongs to the family Solanaceae is one of the most important vegetable grown and consumed worldwide. Rhodanese activity distribution in the stem, leaf, green unripe fruit, yellow ripening fruit, and red ripe fruit tomato plant parts of tomato plant were compared. The yellow ripening fruit had the highest activity followed by the leaf then the stem then green unripe fruit, while the least activity was shown by the red ripe fruit. The activity difference between the red ripe fruit and those of the stem, leaf and yellow ripening fruit was statistically significant. Also, the activity difference between yellow ripening fruit and red ripe fruit was statistically significant. The purified rhodanese from the almond nuts had a specific activity of 4.45 RU/mg with yield of 0.2%. A Km value of 46.34 mM with Vmax 2.10 RU/ml/min were obtained from KCN while a Km value of 26.34 mM with Vmax of 1.52 RU/ml/min was obtained from N