• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.330-337
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• 1995

Forty-six isolates of Fusarium oxysporum collected from infected tomato plants and soils in greenhouses in Sedo, Chungnam and Angang, Kyeongbuk and 8 isolates of F. oxysporum f. sp. lycopersici from Japan and USA were used to determine vegetative compatibility groups (VCGs). Vegetative comaptibility was assessed on the basis of heterokaryon formation among nitrate nonutilizing mutants. All Korean isolates of F. oxysporum f. sp. lycopersici used in this study belonged to the same type of VCG (003) regardless of their geographic origin, cultivar and race, but they were incompatible with the foreign isolates of VCG 0030, 0031, 0032 and 0033. Based on the results, the Korean isolates of F. oxysporum f. sp. lycopersici were classified as a new VCG 003.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.324-329
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• 1995

Severe Fusarium wilt of tomato was observed in greenhouses in Sedo, chungnam and Sandae, Kyeongbuk from march to May 1993. Among the 20 isolates of Fusarium oxysporum isolated from wilted tomato plants and their rhisoplane or rhizosphere, 18 isolates were pathogenic to tomato. All of the pathogenic isolates were identified as F. oxysporum f. sp. lycopersici; they were pathogenic only to tomato and not pathogenic to red pepper, potato and egg-plant. The isolates of F. oxysporum f. sp. lycopersici used in this study could be divided into 2 races according to their pathogenicity to eight differential varieties of tomato. Of 10 isolates tested, 6 were classified as race 1, while 4, as race 2.

• Mycobiology
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• v.36 no.4
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• pp.242-248
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• 2008

The present study was undertaken to explore the inhibitory effect of cyanobacterial extracts of Nostoc commune FA-103 against the tomato-wilt pathogen, Fusarium oxysporum f. sp. lycopersici. In an optimal medium, cell growth, antifungal activity, and antifungal compound production could be increased 2.7-fold, 4.1-fold, and 13.4-fold, respectively. A crude algal extract had a similar effect as mancozeb at the recommended dose, both in laboratory and pot tests. In vitro and in vivo fungal growth, spore sporulation and fungal infection of wilt pathogen in tomato seeds were significantly inhibited by cyanobacterial extracts. Nostoc commune FA-103 extracts have potential for the suppression of Fusarium oxysporum f. sp. lycopersici.

• Journal of Environmental Science International
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• v.28 no.5
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• pp.495-502
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• 2019

This study was conducted to investigated the possibility of inactivating wilt germs (Fusarium oxysporum f. sp. radicis lycopersici) using Dielectric Barrier Discharge (DBD) plasma in a hydroponic system. Recirculating hydroponic cultivation system for inactivation was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic and DBD plasma reactor. Two experiments were conducted: batch and intermittent continuous process. The effect of plasma treatment on Total Residual Oxidants (TRO) concentration change, Fusarium inactivation and growth of lettuce were investigated. In the batch experiment, most of the Fusarium was inactivated at a TRO concentration of 0.15 mg/L or more at four-day intervals. There was no change in lettuce growth after two times of plasma treatment for one week. The intermittent continuous experiment consisted of 30-minute, 60-minute, and 90-minute plasma treatment in 2 day intervals and 30-minute treatment a one-day; most of the Fusarium was inactivated only by treatment for 30-minute every two days. However, if inactivation under $10^1CFU/mL$ is required, it will be necessary to treat for 60 minutes in 2 day intervals. The plasma treatment caused no damage to the lettuce, except the 30 min plasma treatment ay the one-day interval. It was considered that the residual TRO concentration was higher than that of the other treatments.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.290-294
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• 2001

Forty(40) isolates of Fusarium oxysporum isolated from wilting tomato plants at Buyeo of Korea in 1997 were inoculated to four tomato cultivars (Ponderosa, Okitsu 3, Walter, and Zuiken) to examine pathogenic reactions. Isolation rates of F. oxysporum f. sp. lycopersici (FOL) races 1 and 2, and F. oxysporum f. sp. radicis-lycopersici(FORL) were 3.5%, 24.5%, and 57.5%, respectively. Mycelial growth on potato-dextrose agar at different temperature for the three pathogens was $26^{\circ}$. In the pathogenicity tests, however, the range of optimum temperature for disease development for FORL was between 15 and $20^{\circ}$, while that for races 1 and 2 of FOL were specifically pathogenic to tomato only. This suggests that host ranges of FORL and FOL differ significantly.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.362-368
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• 1997

Five formae speciales of Fusarium oxysporum in Korea were examined using RFLP analysis to find the possibility for classification and analyze genetic variations. DNAs from F. oxysporum f. sp. lycopersici, cucumerinum, fragariae, garlic and sesami were used with three recombinant probes such as pFC46, pFC52 and pFC57. Distinct differences among five formae speciales of this fungus were detected in RFLP band patterns based on southern hybridization of genomic DNA using each recombinant clone, which was a repetitive copy probe. Strains belong to four formae speciales could be very stable in genetic variation except f. sp. sesami which has more variation than the others based on the RFLP analysis. They formed their own cluster which has high similarity within the same formae specialis resulted from the UPGMA analysis for genetic relationship analysis and each cluster represented its own formae specialis. The method using three recombinant DNA probes could be a good tool for classification of formae speciales in F. oxysporum.

• Korean Journal of Organic Agriculture
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• v.28 no.1
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• pp.95-108
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• 2020

To develop an environment-friendly fungicide for controlling tomato wilt diseases, antifungal active substance was isolated Rheum australe D. Don roots against Fusarium oxysporum f. sp. lycopersici, a pathogen of tomato wilt, in this study. Methanol extract obtained from Rheum australe roots was successively fractionated with hexane, chloroform, ethyl acetate, butanol and water. The ethyl acetate fraction, which showed the highest antifungal activity, was separated by column chromatography, and 60 subfractions were obtained. The 60 subfractions were anlayzed for antifungal activities by bioassay. The active compound was identified as 5-[(E)-2- (3-hydroxy-4-methoxyphenyl)ethenyl]benzene-1,3-diol (rhapontigenin) by NMR and GC-MS analysis. As a result of testing antifungal activity of rhapontigenin against Fusarium oxysporum, EC₅₀ of rhapontigenin was showed strong antifungal activity at 7.48 mg/L. Therefore, this study showed that the Rheum australe roots extract can be a potential candidate which is a environment-friendly fungicide against Fusarium oxysporum.

• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.202-208
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• 1997

In this study, we evaluated the use of RAPD method to discriminate among strains of Fusarium species including F. oxysporum and f. sp. of F. oxysporum. As a result of the amplication, fifteen primers showed total 180 bands ranging from 0.2 to 3 Kb. Among those 180 bands, 126 polymorphic bands were used for bionominal matrix code (0, 1), and UPGMA dendrogram analysis. Fusarium oxysporum isolate 355 showed high similarity with F. oxysporum isolate 358 at 0.9603. Fusarium roseum isolate 87 and F. oxysporum isolate 358, F. o. f. sp. lycopersici isolate 69 and F. o. f. sp. melongena 68 showed low similarity of 0.3809. Fusarium oxysporum isolate 361 and F. o. f. sp. raphani isolate 218 showed similarity of 0.8730, F. oxysoprum isolate 354 and unidentified Fusarium sp. isolate 228 showed similarity matrix of 0.7936, and F. roseum isolate 87 and F. o. f. sp. raphani isolate 57 showed similarity matrix of 0.5873.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.214-220
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• 2005

Vegetative compatibility groups (VCGs) of Fusarium oxysporum f. sp. radicis-lycopersici isolates collected from tomatoes in Korea were analyzed to determine the genetic characteristics and compared to those of foreign isolates. In comparison of VCG specificity with foreign VCG subgroup testers, Korean isolates were revealed to be VCG 0094 and to be similar to those of Israel and Florida, USA having a 'Universal' property. Results of this study will contribute the effective control of disease through precise estimation of fungal damage, the prediction of new pathogenic isolates appearance, and the movement of foreign pathogens.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.112-118
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• 1999

Strains of Fusarium oxysporum f. sp. lycopersici isolated from Korea, Japan and U.S.A. were used for electrophoretic karyotype (EK) analysis. Chromosome separations on FastLane agarose gels (FMC BioProducts, Rockland, ME), called pulsed field gel electrophoresis (PFGE), were performed by CHEF-DRII apparatus (Bio-Rad Laboratories, Melville, NY) using TAE as a running buffer. To obtain optimal condition for separation of chromosome sized DNAs, variable running conditions such as field strengths, swithching intervals, and running time were applied in CHEF gel electrophoresis. We were able to resolve 9 to 11 chromosome sized DNAs ranging in size from 0.76 to 6.41 Mb in isolates from Korea and estimate that the total genome size was ranging from 35.29 to 38.92 Mb. Distinct differences in length range and genome size exist among isolates from different countries. Isolates from Japan and U.S.A. were resolved 9 to 11 chromosome sized DNAs ranging in size from 1.24 to 6.85 Mb and estimated that the total genome size was ranging from 35.32 to 43.87 Mb. Isolates from variable provinces in Korea had the same or similar chromosomal polymorphism and showed different chromosomal DNA patterns compared to isolates from the other countries.