• Applied Biological Chemistry
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• v.51 no.1
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• pp.38-43
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• 2008

3D-QSARs on the fungicidal activity with N-phenylbenzenesulfonamide and N-phenyl-2-thienylsul-fonamide analogues (1-34) against Fusarium wilt (Fusarium oxysporum) were discussed quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) methods, respectively. Generally, the CoMFA models have better predictability and fitness than the CoMSIA models. The fungicidal activities, according to the information of the optimized CoMF A 2 model $(r^2\;_{cv.}=0.523\;&\;r^2\;_{ncv.}=0.956)$, were dependent on the electrostatic field of the N-phenylbenzenesulfonamide analogues. Therefore, from the results of graphical analyses on the contour maps with the optimized CoMFA 2 model, it is expected that the characters of $R_4-substituents$ on the N-phenyl ring as steric and positive charge favor will contribute to the fungicidal activity against Fusarium wilt.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.41-46
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• 1996

본 실험은 이병 딸기의 조직에서 분리 동정된 시들음병균(Fusarium oxysporum f. sp. fragariae) 균주들의 유？거 변이를 random amplified polymorphic DNA(RAPD) marker들을 이용하여 조사하였다. 총 24개의 딸기 시들음병 균주들의 DNA를 주형으로 하여 16개의 random 10-mer primer들을 사용하여 증폭시킨 결과 총 231개의 marker들을 이용하여 유전적 변이를 조사해 본 결과 크게 RAPD I과 RAPD II의 2개 그룹으로 나눌 수 있었다. RAPD I그룹에 속하는 균주는 VCG A에 속하는 Y1, K1, K2, K3, K4, N2, N3, N4-1, N6-1, N6-2, N8, N9, N10, M1-2-1 균주, VCG B에 속하는 M4-1 균주 그리고 VCG C에 속하는 N1, Y2 균주들이었고, RAPD II그룹에는 VCG B에 속하는 M1-1, M2-2-1, M2-4-2, M3-2, M3-3-2 균주와 VCG D에 속하는 N1 1 균주가 속하였다. 이들 2그룹 간에는 31%의 유사성이 있었다.

• Research in Plant Disease
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• v.26 no.2
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• pp.79-87
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• 2020

Fusarium wilt caused by Fusarium oxysporum f. sp. fragariae (Fof) is the most important diseases of a strawberry field in Korea. We surveyed phylogenetic analysis, pathogenicity test, and fungicide response about Fof isolates isolated from Korea. Twenty-seven isolates of F. oxysporum isolated from strawberry plants were conducted in this study. Specific amplification by Fof specific primer was confirmed in all 26 isolates except Fo080701 isolate. The nuclear ribosomal intergenic spacer region and the translation elongation factor EF-lα gene sequences of isolates revealed three main lineages. Most of all isolates were contained DNA lineage group 1, but 2 and 3 group was shown only one and three isolates, respectively. All isolates were shown in pathogenicity with cv. Seolhyang. The EC₅₀ mean values of prochloraz ranged 0.02-0.1 ㎍/ml except for Fo080701 and effectively inhibited mycelial growth at low concentrations. The EC₅₀ value of metconazole was also 0.04-0.22 ㎍/ml, showing a similar inhibitory effect to that of prochloraz. The EC₅₀ value of pyraclostrobin was 0.23-168.01 ㎍/ml, which was different according to the strain. In the field trial, boscalid+fludioxonil, fluxapyroxad+pyraclostrobin, and prochloraz manganese were selected as the effective fungicides for controlling Fusarium wilt.

• 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.

• 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.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.48-52
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• 2011

This study was conducted to establish the efficient screening system for resistant radish to Fusarium oxysporum f. sp. raphani. Five radish cultivars ('Myoungsan', 'Chungdu', 'Jangsaeng', 'Hannongyeorm', and 'Chungsukungjung') showing different degree of resistance to the fungus were selected. And the development of Fusarium wilt of the cultivars according to several conditions such as root wounding, dipping period of roots in spore suspension, inoculum concentration, and incubation temperature to develop the disease was tested. In distinguishing the resistance degree of the radish cultivars to the disease, non-cut roots were more effective than cut roots. And occurrence of Fusarium wilt of the radish plants increased in the proportion to increase of root-dipping period and spore concentration of the fungus. Thus, optimum conditions to differentiate susceptible and resistant cultivars to the disease were root-dipping period of 0.5 hour and spore concentration of $1{\times}10^7\;conidia{\cdot}mL^{-1}$. Disease severity of Fusarium wilt on the cultivars was changed with incubation temperature and the radish seedlings incubated at $25^{\circ}C$ represented the most difference of resistance and susceptibility to Fusarium wilt. From the above results, we suggest that the efficient screening method for resistant radish to Fusarium oxysporum f. sp. raphani would be to dip non-cut roots of fourteen-day-old radish seedlings in spore suspension of $1{\times}10^7\;conidia{\cdot}mL^{-1}$ for 0.5 hour and to transplant the inoculated plants to plastic pots with fertilized soil, and then to incubate the radish plants at a temperature of $25^{\circ}C$ for development of Fusarium wilt.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.323-332
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• 2024

Circulating hydroponic cultivation has the advantage of reducing soil and water pollution problems caused by discharge of fertilizer components because the nutrient solution is reused. However, cyclic hydroponic cultivation has a low biological buffering capacity and can cause outbreaks of infectious root pathogens. Therefore, it is necessary to develop technologies or disinfection systems to control them. This study used dielectric barrier discharge plasma, which generates various persistent oxidants, to treat Fusarium oxysporum f. sp., a pathogen that causes wilt disease. Batch and intermittent continuous inactivation experiments were conducted, and the results showed that the total residual oxidant was persistent in intermittent plasma treatment at intervals of 2-3 days, and F. oxysporum was treated efficiently. Intermittent plasma treatment did not inhibit the growth of tomatoes.

• Research in Plant Disease
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• v.17 no.1
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• pp.32-37
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• 2011

Field experiments were conducted to evaluate the effectiveness of soil solarization at the Nonsan Strawberry Experiment Station, Korea in 2006 and 2008. In in vitro tests, exposure times to achieve an $LD_{100}$ of Fusarium oxysporum f. sp. fragariae were 6.6 days and 5.1 days at $45^{\circ}C$ and $50^{\circ}C$, respectively. A 100% lethal temperature was $46.7{\pm}0.1^{\circ}C$ for the same fungus. For field trials, solarization was conducted during the summer season using polyethylene mulch in a plastic house. The organic matter+calcium cyanamide+solarization treatment increased pH, organic matter, and calcium content compared to those before treatment in soil analysis, but no effect had an urea+solarization treatment. The temperatures at 10 cm depth were different in each treatment and the highest temperature was recorded from July 30 to August 10. The average temperature in organic matter+calcium cyanamide+solarization treatment at 10 cm depth was $3{\sim}4^{\circ}C$ higher than that in all the other treatments. All solarization treatments reduced the soil population of F. oxysporum f. sp. fragariae at 100% in 2008 relative to the non-treated control. All solarization treatments reduced Fusarium wilt incidence to 0% in 2006 and 2008. The effect of organic matter+calcium cyanamide+solarization against F. oxysporum f. sp. fragariae indicates that there may be future alternatives to traditional solarization for disease control as well as reducing the time needed.

• Korean journal of applied entomology
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• v.1
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• pp.3-10
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• 1962

1) The purpose of the present study is to investigate the effects of culture filtrates of Fusarium oxysporum f. vasinfectum which is known to produce fusaric acid (wilt toxin) on the germination of sesame seeds and the growth of sesame seedlings. 2) Culture filtrates of Fusarium oxysporum 1. vasinfectum used in this study strongly or weakly inhibited the germination and bring about necrosis accompanying black discoloration of sesame seeds. 3) Varietal difference of sesame in the germination response on the culture filtrates of Fnsarium oxysporum f. vasinfectum is not shown in this study. 4) This study reveals that differential five strains of Fnsarium oxysoprum f. vasinfectum used in this study differ greatly in the toxicity of culture filtrates inhibiting the germination of sesame seeds. 5) In the seedling bed added with culture filtrates of Fnsarium oxysporum f. vasinfectum, the growth of shoot as well as root system of sesame seedlings are notably inhibited and necrotic black discoloration appear on both shoot and root system. But in the seedling beds added with weaker concentration of culture filtrates $/(10\%)$ the growth of shoot is slightly promoted. 6) In culture of sesame seedlings with Knop's solution containing 1 to 3 per cent culture filtrates, the growth of shoot as well as root system are slightly retarded" and till the time of development of the third leaves the whole stem and leaf petiole tissue are weakened so that they become thread like accompanying brown discoloration, interveinal light brown area appear in the second leaves, and the third leaves curl from both sides towards the middle with necrotic brown discoloration, especially symptoms of injury on the third leaves are nearly similar that of the leaves of wilted sesame in the field. 7) A pararell relationship is not found between toxicity of culture filtrates and pathogenicity of five differential strains of Fnsarium oxysporum f. vasinfectum used in this study.

• 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.