• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.195-199
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• 2009

To select antifungal surfactants, control efficacy of various nonionic and anionic surfactants on cucumber powdery mildew was evaluated under greenhouse conditions. Among 14 surfactants, pentaetylene glycol monododecyl ether ($C_{12}E_5$), mixture of heptaethylene glycol monodecyl ether and heptaethylene monododecyl ether, and heptaethylene glycol mono-9-octadecenyl ether effectively reduced the development of powdery mildew on cucumber plants. Among the surfactants, $C_{12}E_5$ gave the best control efficacy on the disease and did not show phytotoxic response in cucumber plants. Whereas, fenarimol at a recommended rate (31.3 mg/L) showed less control activity than the surfactant (1,000 mg/L). In addition, mixtures of the surfactant and DBEDC, a protective fungicide, showed high control efficacies against powdery mildews of cucumber and strawberry by additive effect in greenhouse tests.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.339-345
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• 2002

Antifungal substances were isolated from solid cultures of Fusarium equiseti FO-68 obtained from arrowhead and Fusarium sp. FO-510 obtained from egg plant, and then their antifungal activities were investigated against plant pathogenic fungi in vitro and in vivo. An antifungal substance was purifed from rice solid cultures of F. equiseti FO-68 and identified as equisetin. In addition, two antibiotic substances were isolated from solid cultures of Fusarium sp. FO-510 and their chemical structures were determined to be zearalenone and 8'-hydroxyzearalenone. in vitro, equisetin and zearalenone inhibited mycelial growth of most of the plant pathogenic fungi tested, whereas 8'-hydroxyzearalenone hardly inhibited fungal growth. In vitro, equisetin effectively controlled the development of tomato gray mold and tomato late blight. Zearalenone exhibited in vivo antifungal activity against rice blast, rice sheath blight, tomato gray mold, and tomato late blight. However, 8'-hydroxyzearale-none did not control the development of plant diseases except tomato gray mold. This is the first report on the antifungal activities of equisetin, zearalenone, and 8'-hydroxyzearalenone.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.18 no.1
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• pp.213-225
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• 1988

This study was to compare the quality of image by different screen and film combinations. Using the sensitometer measured the speed and average gradient of blue sensitive films and orthochromatic films. The films was combined with rare earth screen LR, LM, LF and conventional screen OM, OH, XOR, OKa and exposed the step wedge to impulse 2, 3, 4, 6, 10, 15, 24,3 8, 60 and measured the density. The following results were obtained: 1. The density of film and film-screen combinations showed significant difference, then in film-screen combinations was significantly different by the screens than films. 2. The speed of blue sensitive films was little different, the TMG of orthochromatic films produced high speed, and the AX film was high average gradient. 3. The relative speed of film-screen combinations showed significant difference, and was high in the OKa of the conventional screens and in the LR of the rare earth screens, especially that of LR screen in the combination with blue sensitive films was high. 4. The average gradient of film-screen combinations showed no significant difference, and was high in the OKa screen and LR/OG combination, and that of OKa/AX combination was highest. 5. The latitude of film-screen combinations showed significant difference by screens, and was high in the LM screen in combination with blue sensitive films and in the OM screen in combination with orthochromatic films. 6. The subject contrast of film-screen combinations showed significant difference by screen, and was high in the LR screen in combination with blue sensitive AX film and orthochromatic TMG film.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.74-78
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• 2001

Two Bacterial strains 1-C and 51-C capable of utilizing aniline as a sole source of carbon and energy were isolated from river waters. Both strains were identified as Pseudomonas rhodesiae based on their physiological and biochemical characteristics and 16S rRNA gene sequence. The strains were able to grow on the mineral salt media containing aniline at concentrations up to 6,000 ${\mu}g/mL$. Pseudomonas rhodesiae 51-C completely degraded aniline in a mineral salt medium containing 300 ${\mu}g/mL$ of aniline as a sole carbon and energy source within 16 hours. The optimum pH and temperature for its growth and aniline degradation were 7.0 and $30^{\circ}C{\sim}35^{\circ}C$, respectively. This is the first report of aniline degradation by P. rhodesiae strains.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.165-171
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• 2006

A new 3-amino-1,3-thiazoline chemical library was synthesized through parallel synthetic technology and in vivo antifungal activity of the compounds were investigated against the typical 6 plant diseases (100 ppm). The characteristic feature of these derivatives was that both a benzyl moiety in C-2 imino and an amino group in C-3 of 2-imino-1,3-thiazoline scaffold were substituted in the molecule respectively. Some compounds showed antifungal activity with selectivity against tomato late blight and rice blast. The fungitoxicity would be attributed to 3,4-dichlorophenyl moiety of the benzyl group.

• The Korean Journal of Pesticide Science
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• v.11 no.1
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• pp.1-7
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• 2007

We have developed an efficient synthesis of 2(5H)-furanones using the microwave-promoted Suzuki-Miyaura coupling reaction and evaluated their fungicidal activities against six fungal pathogens in vivo. In addition, 2-cyclopentenones or 2-cyclohexenones possessing one or two additional methylene groups instead of the oxygen in the 2(5H)-furanone skeleton were also prepared by using the similar method. As the results of in vivo fungicidal screening against 6 plant diseases, a few derivatives displayed specific fungicidal activities against rice blast and tomato late blast. Further studies toward the optimization of the chemical structures are necessary for the development of novel fungicides with high potency.

• Research in Plant Disease
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• v.8 no.2
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• pp.124-130
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• 2002

In 1998, a pathogen isolated from infected onions was identified as Aspergillus niger. At 3$0^{\circ}C$, A. niger AnYD-1 showed the best mycelial growth, spore germination, and high pathogenicity to onions. In spite of the weak inhibitory effect of flusilazole and hexaconazole on the mycelial growth on PDA, they showed the specific inhibitory activity against the formation of spores in the vapour phase. With flusilazole and hexaconazole, the effects of the solvent, the applied concentration and the incubating temperature on the activities inhibiting the spore formation were confirmed. Their inhibitory effect on the spore formation in vapour phase was excellent by solving them with dimethylsulfoxide and dimethylformamide among tested solvents, and applying them at high temperature such as 30~35$^{\circ}C$.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.177-182
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• 1999

A fungal infection assay between normal and transgenic potato harboring chitinase gene in cultivar Belchip was investigated. In the first stage of experiment, seven transgenic lines having 12cm tall were tested for their resistance against potato late blight pathogen Phytophthora infestans by infection with the zoospores, artificially, Susceptibility to potato late blight infection could be classified into three types based on the rate. In terms of resistance to the disease, two lines were higher, two lines were more suppressive, and three lines were similar as compared with the control. In the following experiment, only 2 risistant lines and 1 suppressed line were used to confirm the resistance again. The results of both experiments were similar. Furthermore, two highly resistant transgenic lines grown in field exhibited a higher resistance than control under the conditions of natural ocurrence of the fungal disease.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.359-366
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• 2006

The protective effect of kresoxim-methyl was investigated on 6 important plant diseases, and the vapour effect of it did on barley and cucumber powdery mildews, respectively. With 2.0 ${\mu}g\;mL^{-1}$ of kresoxim-methyl, its high activities against wheat leaf rust and barley powdery mildew were showed such as 92 and 100%, while activities were very low against rice sheath blight, tomato gray mold, and tomato late blight. In vapour phase control activity of kresoxim-methyl against barley powdery mildew was positively correlated with the applied concentrations, except for azoxystrobin and metominostrobin. With 200 ${\mu}g\;L^{-1}$, its control value was 71.9%. When 1000 ${\mu}g\;m^{-3}$ of kresoxim-methyl in vapour phase was applied on 4 plants of cucumber in a vinyl chamber, 51.1% of control value on kresoxim-methyl-treated cucumber was showed 7 days after the application.

• The Korean Journal of Pesticide Science
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• v.6 no.3
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• pp.202-208
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• 2002

A phytotoxin was purified by repeated chromatography from liquid cultures of Fusarium oxysporum BG isolated from barnyardgrass. Its chemical structure was determined to be dehydrofusaric acid by mass and NMR spectral analyses. The substance showed a potent phytotoxic activity against growth of duckweed with a $EC_{50}$ value of $1.5{\mu}g/ml$. It also inhibited the root growth of barnyard millet, cress, barnyard grass, and rice cultivar 'Dongjin'. However, it had no inhibitory activity against seed germination of barnyard millet and cress, and the shoot growth of the four plant species.