• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.360-368
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• 1997

Shepherd's purse (Capsella bursa-pastoris) is one of the minor but important vegetable in Korea. The present study records 4 fungal diseases of this plant occurring under natural condition for the first time in Korea. They are white rust caused by Albugo candida, downy mildew by Peronospora parasitica, leaf spot by Pseudocercosporella capsellae, and powdery mildew by Erysiphe cichoracearum of these, white rust and downy mildew were most common causing severe damages and should be managed for the development of greenhouse cultivation of this plant.

• Korean Journal Plant Pathology
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• v.3 no.1
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• pp.43-53
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• 1987

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.3 no.11
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• pp.47-48
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• 1982

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.540-549
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• 2016

Plant residues serve as substrates for the proliferation and overwintering of plant pathogenic fungi in soil. Effects of the biocontrol fungus Trichoderma harzianum on the colonization of wheat straw by the plant pathogenic fungus Fusarium solani were investigated under different soil moisture regimes (-50 vs. -500 kPa) in non-sterile soil. T. harzianum ThzID1-M3 and/or F. solani were added along with wheat straw to non-sterile soils. ThzID1-M3, other Trichoderma species, and F. solani were monitored for a 21-day period using quantitative PCR. ThzID1-M3 reduced the colonization of F. solani on wheat straw (p < 0.05) under both moisture regimes, and F. solani reduced the colonization by ThzID1-M3 and other Trichoderma species (p < 0.05), thus suggesting competitive inhibition between ThzID1-M3 and F. solani. Colonization by ThzID1-M3 and generic Trichoderma was improved in the wet soil (p < 0.05), but colonization by F. solani did not differ between the two moisture conditions. Thus, the inhibitory effect of ThzID1-M3 was greater in the wet soil (p < 0.05). The growth competition between ThzID1-M3 and F. solani to colonize plant debris suggests that the biocontrol fungus T. harzianum may reduce the potential of the plant pathogen, F. solani, to survive and proliferate on crops.

• Korean journal of applied entomology
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• v.14 no.1 s.22
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• pp.1-5
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• 1975

The study has been carried out for the development of an inoculation method in screening resistant varieties and/or lines to bacterial leaf blight of rice with special consideration on plant ages and inoculum concentrations. A higher incidence of the disease was found on younger plants than on the older ones when the plants were inoculated with the same concentration of inoculum by clipping method under the same circumstances. Applications of extremly high concentration of inoculum resulted the death of younger seedlings from all varieties within short period after inoculation, and the inoculum that was lower than optimum concentration failed in distinguishing varietal characteristics in regard of resistance. The proper inoculum size for the screening of resistance among the varieties and/or lines depended on the age of plants. The optimum concentration of inoculum for the plant age of 14, 37, 48 and 58days was $10^6,\;10^7,\;10^7-10^{-9}\;and\; 10^9 cells/ml.,$ respectively.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.201-209
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• 2006

Antifungal activities of 43 different plant oils were evaluated against different phytopathogenic fungi. Thyme oil showed highest antifungal activity among the tested oils. The major of thyme oil were found to be thymol, carvacrol, bomeol, p-cymene and linalool. Thymol and carvacrol were found to be responsible for thyme's antifungal activity. The spore germination assay was conducted on Alternaria mail and Botrytis cinerea. Thymol and carvacrol strongly inhibited spore germination in the fungi test. In addition, thymol and carvacrol showed a curative effectiveness to gray mold disease on cucumber crop. The antifungal activities of alkylphenol and alkylaniline compounds, which has similar molecular structure to that of thymol or cavacrol, were also tested. It was found that alkylphenol compounds also show higher inhibition to spore germination. Thus, thymol, carvacrol and alkylphenol compounds can be used an potent antifungal agents.

• Korean Journal of Organic Agriculture
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• v.7 no.1
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• pp.137-146
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• 1998

Various rhizobacteria was isolated, and was bacterialized into the substrates to clarify the plant growth promoting effects of rhizobacteria on the early growth of red peper seedlings. Total 125 bacterial isolates were primarily isolated and purified from the soils in greenhouse. And four strains were finally screened, based on the antifungal activities against Fusarium sp., Pythium sp. and Rhizoctonia sp. of red pepper plants. The strongest antifungal strain RB 109 has a antagonistic activity against Fusarium sp., Pythium sp. and Rhizoctonia sp. in terms of 66.0%, 65.0% and 66.1%. Early growth of red pepper seedlings was promoted, when cultured solution of rhizobacteria RB 109 was bacterialized into the substrates. Antifungal rhizobacteria RB 109 was identified as Pseudomonas sp. related strains, which has a similarity of 82% to the Pseudomonas sp.

• Research in Plant Disease
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• v.23 no.1
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• pp.42-48
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• 2017

Chlorella is one of the microorganisms which can live autotrophically by their own photosynthesis. It was previously revealed that pre-treatment of Chlorella fusca caused a suppression of appressorium formation on the cucumber leaves after inoculation with Colletothrichum orbiculare. In this study, the ultrastructures of C. orbiculare on the cucumber leaves pretreated with C. fusca were observed using both scanning electron microscope (SEM) and transmission electron microscope (TEM). The SEM images revealed that most fungal conidia and hyphae were attached with lots of C. fusca cells. Also, the conidia could germinate but not form appressorium, which is necessary to penetrate into host tissue. These observations suggested that C. fusca adjoined to the fungus may play a role in suppression of the appressorium formation. On the other hand, the observations of TEM showed no remarkable cytological differences on the ultrastructures of the intracellular hyphae between in the pre-treated and untreated leaves. It seemed that the fungus could grow in the pre-treated plant tissues as in the untreated one. Based on these observations, it is suggested that the suppression of appressorium on the leaf surfaces by the C. fusca cells may be a main cause of the reduction of the anthracnose disease.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.103-107
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• 2016

To establish a rapid and accurate detection of Phytophthora pinifolia, which is a quarantine pathogenic fungus in Korea, a species-specific primer was developed based on the ras-related protein (Ypt1) gene. Species-specific primer based on the DNA sequences of Ypt1 gene amplified 193 bp polymerase chain reaction (PCR) product for P. pinifolia. The primer pair yielded the predicted PCR product size exactly in testing with target pathogen DNAs, but not from the other 10 species of Phytophthora and 14 species of other phytopathogenic fungi. The primer pair also showed only the species-specific amplification curve on realtime PCR on target pathogen DNA. The detection sensitivity of real time PCR using species-specific primer pair was 10 to 100 times higher than conventional PCR, with 1 to $10pg/{\mu}L$.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.162-166
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• 2002

Two bithiazole-type antibiotics were isolated from the culture broth of a Myxococcus species which isolated from the marine sediment off the coast of Cheju Island, Korea. The structures of these metabolites were determined as KR025 and melithiazole F, previously reported bithiazoles, using combined spectroscopic methods. Both compounds showed an antifungal activity. In in vivo tests, these compounds exhibited potent controlling activities against tomato late blight, wheat leaf rust, and barley powdery mildew with control values more than 80% at a concentraton of 20 $\mu\textrm{g}$/ml.