• The Korean Journal of Mycology
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• v.16 no.3
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• pp.157-161
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• 1988

The vegetative nuclear divisions in hyphae and chromosome numbers were studied with the aid of Giemsa-HCl techniques from 10 strains of Fusarium oxysporum. The entire nuclear division process occurred within an intact nuclear envelope like other fungus. The results confirmed that 2 strains(F. oxysporum S Hongchun D2, F. oxysporum S Jinyang 4) were n=4; 3 strains(F. oxysporum f. sp. lini KFCC 32585, F. oxysporum f. sp. melongenae KFCC 34743 and F. oxysporum f. sp. raphani) n=5; 2 strains(F. oxysporum f. sp. vasinfectum, and F. oxysporum f. sp. mori KFCC 34742) n=6; 3 strains(F. oxysporum f. sp. cucumerium, F. oxysporum f. sp.niveum, and F. oxysporum f. sp. pisi) n=7.

• The Korean Journal of Mycology
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• v.17 no.2
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• pp.76-81
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• 1989

The mitotic nuclear divisions in hyphae and chromosome number in 10 strains of Fusarium oxysporum were studies with the aid of Giemsa-HCl techniques. The chromosome number of fungi was ranged from 4 to 8. Of the 10 strains (F. oxysporum f. sp. lycoperici, F. oxysporum Kangnung D2) are n=4; two (F. oxysporum Sachun3, F. oxysporum S Kohung D2) n=5; five (F. oxysporum S Kohung 3, F. oxysporum CS Hongchun D16, F. oxysporum S Bosung 5, F. oxysporum SSunchun4 and F. oxysporum S Haenam 4) n=7 and one (F. oxysporum from the Australia) are n=8. These results along with my previous papers indicate that the basic chromosome number of the F. oxysporum may be n=4 and may have been evolutionary modification within this fugal group through diploidy and aneuploidy. As additional strains are studied, the chromosome number should help to reveal steps possible phylogenetic relationship within the group as well as more clearly defining taxonomic group and variation factors.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.288-300
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• 1994

Fusarium oxysporum was isolated most frequently, followed by F. moniliforme, and F. solani from infected asparagus plants grown in the field. In pathogenicity tests both with seedlings and plantlets, F. moniliforme showed higher virulence than Fusarium oxysporum did in general. Fusarium moniliforme showed more consistent virulence on both seedlings and plantlets than F. oxysporum did. Fusarium oxysporum showed higher virulence on plantlets than on seedlings. Fusarium solani showed very weak or no sign of virulence on seedlings and plantlets, respectively, in both tests. In protection tests with plantlets, most protection of asparagus against virulent fusarial infections occurred when challenge isolates were inoculated five or seven days after inoculation of protective fusarial species. Avirulent F. oxysporum was a more effective protective agent against infection of F. moniliforme than it was against F. oxysporum. Fusarium solani was more effective against infection of F. oxysporum than it was against F. moniliforme.

• 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.

• 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.

• Research in Plant Disease
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• v.30 no.1
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• pp.26-33
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• 2024

In 2023, symptoms like damping-off disease were observed in 74 paprika growing in greenhouses in Cheorwon-gun, Gangwon-do, Korea. In this study, we tried to find the cause of the damping-off disease outbreak. We collected symptomatic seedlings and observed the typical crescent-shaped conidia of Fusarium oxysporum by microscope. To confirm the presence of F. oxysporum in the samples, polymerase chain reaction was performed using primers specific for F. oxysporum; the resulting sequence showed 99.11% identity with F. oxysporum. To confirm the pathogenicity of the F. oxysporum (CW) isolated from the samples, healthy paprika plants were inoculated with F. oxysporum CW and damping-off symptoms were observed 2 weeks later. To investigate whether the damping-off disease outbreak in Cheorwon-gun was caused by F. oxysporum-contaminated seeds, 100 paprika seeds were disinfected and placed in Murashige and Skoog medium. Typical pink F. oxysporum hyphae were found only in control non-disinfected seeds. An 18S rRNA-based and a TEF genebased phylogenetic analysis showed that the F. oxysporum CW isolate was not grouped with a F. oxysporum isolate reported from Cheorwon-gun in 2019. This study is the first report that an outbreak of damping-off disease in paprika in Cheorwon-gun, Gangwon-do, Korea, was caused by contamination of F. oxysporum seeds.

• Korean Journal Plant Pathology
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• v.3 no.1
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• pp.8-12
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• 1987

Fusarium oxysporum, F. moniliforme, F. solani, F. equiseti, F. semitectum, and F. sporotrichioides were detected from seeds, roots and cultivated soil of Phaseolous vidissimus collected from Kyung-gi Provincial Rural Development Administration. The rate of seedling desease incidence was $60\%$ by testing of seed germination using a large petri-dish. According to the blotter method, F. moniliforme showed $7\%$ infection at seed-coat and $2\%$ at cotyledon and embryo. Their pathogenicities of F. moniliforme, F. semitectum, F. equiseti, and F. sporotrichioides isolated from seeds were recognized on seedlings by water-agar test tube methods. F. oxysporum and F. solani isolated from infected-roots had their pathogenicity by water-agar test tube method but were weakly pathogenic by soil treatment method. Their pathogenicities of F. oxysporum. F. solani and F. uiseti isolated from cultivated-soil were recognized by water-agar test tube method. These F. oxysporum and equiseti isolates had their pathogenicities but F. solani was weakly pathogenic by soil treatment method.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.264-270
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• 2004

Fusarium oxysporum f. sp. fragariae is a fungal pathogen causing strawberry wilt disease. The random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphisms (RFLPs) of intergenic spacer (IGS) region of rDNA were used to identify genetic variation among 22 F. oxysporum f. sp. fragariae isolates. All isolates could be distinguished from each other by RAPD analysis and RFLP of 2.6 kb amplified with primer CNS1 and CNL12 for IGS region of rDNA. Cluster analysis using UPGMA showed eight distinct clusters based on the banding patterns obtained from RAPD and rDNA RFLP. These results indicate that F. oxysporum f. sp. fragariae isolates are genetically distinct from each other, There was a high level genetic variation among F. oxysporum f. sp. fragariae.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.626-632
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• 2013

In the course of a developing screening method for resistant radish to Fusarium oxysporum f. sp. raphani, we found that the fungus produces phytotoxic compound against Raphanus sativus. The culture filtrate of F. oxysporum f. sp. raphani KR1 represented the strongest phytotoxicity when the fungus was incubated in the malt extract broth with 150 rpm at $25^{\circ}C$ for 14 days. Under bioassay-guided purification, we isolated a substance from liquid culture of F. oxysporum f. sp. raphani KR1, with phytotoxic effect against R. sativus. The compound was identified as fusaric acid by mass and nuclear magnetic resonance spectral analyses. Phytotoxicity of the compound against cruciferous vegetable crops, including radish, cabbage, and broccoli, was investigated. Fusaric acid represented phytotoxicity on radish seedlings by concentration dependant manner. And the phytotoxin demonstrated strong phytotoxicity on the resistant cultivars as well as susceptible cultivars of radish to F. oxysporum f. sp. raphani. In addition, fusaric acid isolated from the fungus also showed a potent phytotoxic efficacy against non-host Brassicaceae crops of the fungus such as cabbage and broccoli. The results demonstrate that fusaric acid produced by F. oxysporum f. sp. raphani is non-host-specific toxin and for screening of resistant radish to the fungal pathogen, spore suspension of the fungus without the phytotoxin has to be used.

• 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.