• Journal of Plant Biology
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• v.30 no.1
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• pp.59-67
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• 1987

To verify allelopathic effect of tomato plants a number of labovatory experiments, seed germination and seedling growth with aqueous extracts and leachates form the tomato plants, have performed. Germination percentage of the tested species was decreased by treatment with leaf, stem and root extracts as extracting time elapses. The leaf extract more inhibits the germination of the seeds than both stem and root extracts. Leachate collected from the tomato plants decreases as much as 50% of the growths in elongation as well as dry weight of seedlings of lettuce and egg plant. It is observed that with a paired-plants grown in U tube pot the tomato roots have excreted allelochemicals to inhibit the growth of the tested species and volatile substances from the tomato plants have suppressed to dry weights of lettuce, to elongation and dry weights of grapevine planted near the tomato plants.

• Korean Journal Plant Pathology
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• v.10 no.1
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• pp.18-24
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• 1994

Multiplications and pathogenic reactions of different pepper and tomato strains of Xanthomonas campestris pv. vesicatoria were evaluated in the most upper leaves of pepper and tomato plants at different growth stages. Hypersensitive reactions were induced in mature pepper plants by inoculation with only the tomato strains but not with the pepper strains, suggesting the expression of age-related resistance in pepper plants. The age-related resistance also seems to be correlated with an apparent inability of the bacteria to multiply as extensively in mature as in young plants. No significant differences among the Korean and U. S. pepper cultivars tested were found in bacterial multiplication, irrespective of bacterial stain or plant growth stage. Korean tomato cultivars tested also were highly susceptible to either tomato or pepper strains during the development of tomato plants.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.256-262
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• 2009

The potential of. nonpathogenic Fusarium oxysporum strain Avr5, either alone or in combination with chitosan and Bion, for inducing defense reaction in tomato plants inoculated with F. oxysporum f. sp lycopersici, was studied in vitro and glasshouse conditions. Application Bion at concentration of 5, 50, 100 and $500{\mu}g$/ml, and the highest concentration of chitosan reduced in vitro growth of the pathogen. Nonpathogenic F. oxysporum Avr5 reduced the disease severity of Fusarium wilt of tomato in split plants, significantly. Bion and chitosan applied on tomato seedlings at concentration $100{\mu}g$ a.i./plant; 15, 10 and 5 days before inoculation of pathogen. All treatments significantly reduced disease severity of Fusarium wilt of tomato relative to the infected control. The biggest disease reduction and increasing tomato growth belong to combination of nonpathogenic Fusarium and Bion. Growth rate of shoot and root markedly inhibited in tomato plants in response to tomato Fusarium wilt as compared with healthy control. These results suggest that reduction in disease incidence and promotion in growth parameters in tomato plants inoculated with nonpathogenic Fusarium and sprayed with elicitors could be related to the synergistic and cooperative effect between them, which lead to the induction and regulation of disease resistance. Combination of elicitors and non-pathogenic Fusarium synergistically inhibit the growth of pathogen and provide the first experimental support to the hypothesis that such synergy can contribute to enhanced fungal resistance in tomato. This chemical could provide a new approach for suppression of tomato Fusarium wilt, but its practical use needs further investigation.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.744-746
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• 1998

Control effect of acidified nutrient solution on bacterial wilt of tomato plants was tested by examining the degree of bacterial growth inhibition and plant damage due to the acidity. Ralstonia solanacearum, the causal bacterium of bacterial wilt of tomato plants, showed 105 times population reduction when the bacterium was cultured in the acidified nutrient solution (pH 3.5∼4.0). However, fruit yields were decreased only fifteen to twenty percents. These results suggest that control of the bacterial wilt of tomato plants may be possible with supplying acidified nutrient solution.

• Research in Plant Disease
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• v.28 no.2
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• pp.108-111
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• 2022

In December 2020, stem and leaf rot symptoms in small-fruited tomato (Solanum lycopersicum) plants were observed in a farmer's vinyl greenhouse located in Pyeongtaek, Gyeonggi Province, Korea. The incidence of diseased plants in the vinyl greenhouse was 2-6%. Seven single-spore isolates of Phoma sp. were obtained from the diseased stems and leaves. All the isolates were identified as Boeremia linicola based on the cultural, morphological and molecular characteristics. Two isolates of B. linicola were tested for pathogenicity on stems and leaves of small-fruited tomato and large-fruited tomato using artificial inoculation. All the tested isolates caused stem and leaf rot symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the vinyl greenhouse investigated. This is the first report of B. linicola causing stem and leaf rot in tomato.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.151-161
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• 2021

Fusarium wilt disease of tomato plants caused by Fusarium oxysporum f.sp. lycopersici (FOL race2) is one of the most important diseases of tomatoes worldwide. In the competition between tomato and FOL, the FOL can win by overcoming the immune system of tomato plants. Resistant interaction between the FOL race2 and tomato plants is controlled by avirulence genes (AVR2) in FOL and the corresponding resistance genes (I2) in tomato plants. In this study, 7 FOL isolates (KACC) were used to test their pathogenicity, and FOL race2 was selected because it is a broad problem in Korea. The Fol40044 isolates showed the most severe pathogenicity, and the avr2 gene was also isolated and identified. Moreover, to select resistance, 20 tomato varieties were inoculated with the Fol40044, and the degree of pathogenicity was evaluated by analyzing the expression of the avr2 gene. As a result, three resistant tomato varieties (PCNUF73, PCNUF101, PCNUF113) were selected, and the expression of the avr2 gene was much lower than that of the control Heinz cultivar. This result shows that the screening assay is very efficient when the avr2 gene is used as a marker to evaluate the expression level when selecting varieties resistant to tomato wilt disease. Based on these results, it is possible to isolate the I2 gene, which exhibits resistance and molecular biological interactions with the AVR2 gene from the three tomato-resistant varieties. The I2 gene provides breeders more opportunities for Fusarium disease resistance and may contribute to our understanding of their interactions with the FOL and host plant.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.282-284
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• 1995

Grey leaf spot on tomato plants was first observed in Sedo-myeon, Puyo-kun, Chungnam province of Korea in 1994. This disease which had not been reported before in Korea exhibited different symptoms from those of other leaf spot diseases on tomato plants. The symptoms were characterized by small irregular-shaped spots on leaves at the initial stage of the infection, subsequent spread and coalescence of the spots throughout the leaves with ultimate necrosis, and abscission from the plants. When healthy tomato plants were inoculated with a conidial suspension of the fungus isolated from the lesion of a diseased plant in a field, the same characteristic symptoms as those in the field were produced. Furthermore, the same pathogen could be reisolated from the lesions formed buy the inoculation. Conidial characteristics of the pathogen were as follows; oblong shape with constricted 3 transverse septa, round-shaped base, round- or point-shaped apex, size of 45~75$\times$12.5~17.5 ${\mu}{\textrm}{m}$, and 3.5 : 1 ratio of length to width. The pathogen was identified as Stemphylium lycopersici and thus this is the first report on the occurrence of grey leaf spot disease on tomato plants caused by s. lycopersici in Korea.

• The Plant Pathology Journal
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• v.39 no.5
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• pp.466-485
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• 2023

Crop productivity can be obstructed by various biotic and abiotic stresses and thus these stresses are a threat to universal food security. The information on the use of viruses providing efficacy to plants facing growth challenges owing to stress is lacking. The role of induction of pathogen-related genes by microbes is also colossal in drought-endurance acquisition. Studies put forward the importance of viruses as sustainable means for defending plants against dual stress. A fundamental part of research focuses on a positive interplay between viruses and plants. Notably, the tomato yellow leaf curl virus (TYLCV) and tomato chlorosis virus (ToCV) possess the capacity to safeguard tomato host plants against severe drought conditions. This study aims to explore the combined effects of TYLCV, ToCV, and drought stress on two tomato cultivars, Money Maker (MK, UK) and Shalala (SH, Azerbaijan). The expression of pathogen-related four cellulose synthase gene families (CesA/Csl) which have been implicated in drought and virus resistance based on gene expression analysis, was assessed using the quantitative real-time polymerase chain reaction method. The molecular tests revealed significant upregulation of Ces-A2, Csl-D3,2, and Csl-D3,1 genes in TYLCV and ToCV-infected tomato plants. CesA/Csl genes, responsible for biosynthesis within the MK and SH tomato cultivars, play a role in defending against TYLCV and ToCV. Additionally, physiological parameters such as "relative water content," "specific leaf weight," "leaf area," and "dry biomass" were measured in dual-stressed tomatoes. Using these features, it might be possible to cultivate TYLCV-resistant plants during seasons characterized by water scarcity.

• The Korean Journal of Ecology
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• v.21 no.2
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• pp.151-156
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• 1998

the phytotoxic effects of volatile substances emitted from the tomato plant (Lycopersicon esculentum) on receptor plants such as Bidens bipinnata, Plantago asiatica, Lactuca sativa, Eragrositis ferruginea and Achyranthes japonica were investigated. Bolatile substances from the leaves inhibited seedling growth of receptor plants in the laboratory tests. The inhibition response varied with the concentration of compounds. To identify the phytotoxic compounds from tomato plant a GC/MS method was employed. Forth compounds, such as trans-2-hexeal, linalool, phenylacetaldehyde, methlsalicylic acid and tetradecanaic acid were identified from the essential oil of tomato plants. The findings suggest that the tomato plant may have allelopathic potential.

• Mycobiology
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• v.46 no.2
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• pp.147-153
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• 2018

Certain beneficial microorganisms isolated from rhizosphere soil promote plant growth and induce resistance to a wide variety of plant pathogens. We obtained 49 fungal isolates from the rhizosphere soil of paprika plants, and selected 18 of these isolates that did not inhibit tomato seed germination for further investigation. Based on a seed germination assay, we selected four isolates for further plant tests. Treatment of seeds with isolate JF27 promoted plant growth in pot tests, and suppressed bacterial speck disease caused by Pseudomonas syringae pathovar (pv.) tomato DC3000. Furthermore, expression of the pathogenesis-related 1 (PR1) gene was higher in the leaves of tomato plants grown from seeds treated with JF27; expression remained at a consistently higher level than in the control plants for 12 h after pathogen infection. The phylogenetic analysis of a partial internal transcribed spacer sequence and the b-tubulin gene identified isolate JF27 as Aspergillus terreus. Taken together, these results suggest that A. terreus JF27 has potential as a growth promoter and could be used to control bacterial speck disease by inducing resistance in tomato plants.