• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.45-51
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• 1991

There had been no reports of Trichophyton tonsurans infection in Korea yet. We have much chances to import the organism through international travels and exchanges. But we, Korean, have no experiences to observe T. tonsurans. Author tried mycological studies with T. tonsurans isolated in New Orleans, USA. The results are as follows : Gross findings of T. tonsurans showed that fine granular surface with light yellow hue or white color and groving in the central area on the front side and mahogany brown color on the reverse side. On the urease test, various reddish discoloration was noted. Microscopic findings showed that septated hyphae, macroconidia, chlamydoconidia and microcondia. Macroconidia were 3-5 septated, smooth-surfaced, and were found more frequently in the whitish colony. Microconidia were characteristic in their arrangement and shape ; round or oval shaped microconidia laterally to hyphae, some were match-head like terminal swelling. Hair perforation test showed positive results in 16 strains among 19 tested strains. All these findings are similar to T. rubrum and T. menatgrophytes, the most frequent isolates of dermatophytes in Korea. And we have to pay an attention to diffentiate carefully.

• The Korean Journal of Mycology
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• v.22 no.1
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• pp.50-61
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• 1994

From soil samples, 380 antagonistic microorgnisms were isolated. Among the isolates, 42 strains had mycelia growing inhibition ability against Fusariun solani, ginseng root rot causing pathogen. Isolates CHA 1 and S-PFHR 6 were proposed as antagonists for this study and they were identified as Promicromonospora sp. and Pseudomonas pseudoalcaligenes respectively. As an antagonism against hyphae of F. solani in dual culture test, CHA 1 and S-PFHR 6 inhibited linear growing, caused abnormal branching, and the membrane projection which formed by cell wall destruction. The secondary metabolites contained in the culture filtrates which prepared from PD broth and Nutrient broth inhibited the spore germination to 14.3%. The culture filtrate of S-PFHR 6 which prepared by a little amount of soil extract addition to nutrient rich medium had more strongly. inhibited the spore germination and spore germination decreased to less than 4.0% in it. The soil used in this study had fungistasis and the germination rate of macroconidia and chlamydospore of F.solani was 19.4% and 17.7% respectively. The steam sterilized soil lost fungistasis and germination rate of conidia increased to more than 97.9%. The soils amended with the propagule of CHA 1 and S-PFHR 6 increased fungistasis and the germination rate of macroconidia decreased to 14.7% and 11.7% respectively in each treatments. But the soil ammended with glucose and asparagine annulled fungistatic ability and the germination rate of macroconidia increased to more than 48.0%. As an antagonistic activity of the secondary metabolites of two antagonistic isolates in soil, the germination rate of macroconidia of F. solani was 9.3% in the soil amended with the culture filtrate of CHA 1 but the culture filtrate of S-PFHR 6 had no such activity. In the soil which treated with antagonist propagule or culture filtrate, the chlamydospore germination rate was lower than that in natural soil. The addition of glucose and asparagine to antagonist propagule treated soil did not enhanced the chlamydospore germination.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.664-667
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• 1998

Leaf spot of Cymbidium hybrida caused by Fusarium sp. was observed at major cultivating areas including Seosan and Cheonan of Korea from 1996 to 1998. The major symptoms of the disease were small brown to black spots, 1∼2 mm I diameter, with yellow halo. Based on the mycological characteristics, Fusarium sp. isolated from the lesions was identified as Fusarium proliferatum. Macroconidia were slender, falcate to almost straight, usually 3 to 5 septate and thin walled. Microconidia were formed in chains from polyphialides, clavate or oval, usually 1-celled with flattened base. Chlamydospores were absent. The fungus showed pathogenicity to Cymbidium hybrida.

• Korean Journal Plant Pathology
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• v.10 no.1
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• pp.64-67
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• 1994

Crown rot was found find tomatoes growing on a rockwool culture system in a glasshouse at Dongkwangyang in 1992. The disease occurred on the stem of 'Trust' tomato plants with 3~4 cluster of flowers. Infected plants showed stem girdling and necrosis at or slightly above the rockwool line. Internal tissues of crown and stem including cortex, vascular bundle, and pith became decayed resulting in a chocolate-brown discoloration extending no more than 10~15 cm above the crown. Diseased tomato plants with the similar symptoms were found at Ansung and Taejon where tomatoes were grown on either rockwool or soil in plastic greenhouses. The size of macroconidia of Fusarium isolated from a diseased plant was 26.0~41.6$\times$2.9~4.7${\mu}{\textrm}{m}$, and microconidia were formed on short monophialide and the size was 3.6~12.5$\times$2.9~3.6 ${\mu}{\textrm}{m}$. Morphological characteristics and inoculation tests indicated that the causal organism of the disease was Fusarium oxysporum.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.191-196
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• 2005

Fusarium head blight (FHB) is a severe disease problem that affects the quality and yield of barley grain. The evaluation of FHB resistance is difficult because environmental conditions greatly influence FHB infection and development. The objectives of this study were to: 1) establish an efficient screening method for selecting resistant barley to FHB, 2) compare FHB severity between the cut-spike method and pot-plant method for development of mass screening, and 3) estimate FHB resistance for barley germplasms. Barley cultivars and lines were evaluated for reaction to FHB in controlled-greenhouse condition. Spikes were spray-inoculated with a suspension $(5.0\times10^5\;macroconidia\;mL^{-1})$ of Fusarium graminearum SCK-O4 strain, and then kept in a greenhouse at $18-25^{\circ}C$ with $80-100\%$ relative humidity. Inoculation were employed at 3 different heading growth stages (heading date, three days after heading, and five days after heading). The inoculation was performed in 2 consecutive days in order to avoid escapes. The inoculated plants were maintained in the greenhouse at 4 different free moisture periods (1, 3, 5, and 7 days). The percentage of FHB severity was scored from 0 to 9 according to the rate of infected kernels per spike, and three spikes were evaluated per replication with 3 replicates. There were significant differences of FHB severity depending on the different free moisture periods, but not by the inoculation at different heading stages. The optimum evaluation point of FHB severity in the greenhouse condition was on the 7th day under free moisture condition after inoculation at the heading date. Infection level in cut-spike method highly correlated with that in pot-plant method. This suggested that cut-spike method is useful in evaluating of FHB resistance in barley. Six cultivars, such as Jinkwang, Buheung, Atahualpha 92, Chevron-b, Gobernadora-d, and MNBrite-c, were selected as resistant varieties to FHB. Correlation coefficient for the FHB severity evaluated by the pot-plant method between two seasons was 0.794, indicating the stability and accuracy of the screening method.

• Research in Plant Disease
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• v.12 no.3
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• pp.178-184
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• 2006

The 18 isolates of soybean red crown rot pathogen(Calonectria ilicicola) were isolated from infected soybean plants showing chlorosis symptom and red perithecia sign in 2002 and 2003 season in Korea. The morphological characteristics of the typical isolate SC03-15, such as macroconidia and macrovesicles in anamorph as well as perithecia, asci and ascospores in teleomorph, were observed from red crown rot pathogens. The perithecia were red-brown globose to ovoid, and $357.9(312.5{\sim}391.5.7){\mu}m$ high and $474.3(419{\sim}535){\mu}m$ diameter. Asci were hyaline and clavate and included 8 ascospores, which were straight to slightly curved, 1(-3)-septate, and $36.9(31.1{\sim}49.4){\times}5.2(4.5{\sim}6.1){\mu}m$. Macroconidia in anamorph were cylindrical, hyaline and in size $73.2(68.1{\sim}77.6){\times}5.8(4.9{\sim}6.8){\mu}m$. Further identification process was performed through molecular method, such as a phylogenetic analysis by rDNA sequencing of ITS and $\beta$-tubuline genes of all isolates tested in this study. All isolates were identified as Calonectria ilicicola by DNA sequencing of ITS and $\beta$-tubuline genes, and morphological characteristics.

• Korean journal of applied entomology
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• v.22 no.3 s.56
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• pp.203-207
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• 1983

Biological, physical and chemical characteristics of suppressive and conducive soils to ginseng root rot were investigated. Population of antagonistic microorganisms to Fusarium solani was much higher in suppressive soils than in conducive soils, whereas the numbers of Fusarium species were smaller in suppressive soils. Mycelial growth and chlamydospore formation of Fusarium solani were inhibited in suppressive soils. In the water extract of suppressive soils, lysis of germination tube and macroconidia of F. solani was occurred by antagonistic microorganisms at 4 hours after treatment. There were no significant differences in physical and chemical characteristics between supressive soils and conducive soils to ginseng root rot, however, clay content of suppressive soils was a little higher than that of conductive soils.

• Korean journal of applied entomology
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• v.19 no.4 s.45
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• pp.228-233
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• 1980

The infection rate of soybean black root rot disease caused by Calonectria crotalariae was about $14\%$. The isolated fungi from the infected soybean roots and stems were Calonectria crotalariae, Fusarium solani, F. roseum, Phomopsis sojae, Pythium aphanidermatum, Rhizoctonia solani and Macrophomina sp. Among them, C. crotalariae was the most virulent pathogen under the laboratory conditions. Mycelial growth and microsclerotial formation were good on PSA containing 1000cc of water, 100g of potato and 20g of sugar. Mycelial growth, sporulation and microsclerotial formation were good on sterilized root. Perithecial formation was better in the dark condition than in the light. Survival of macroconidia was not available between $0\~25\%$ soil water content. Microsclerotia and mycelium in infected plant debris were survived for 4 months at to $8\%\;50\%$ soil water content. The plant height, when inoculated with $1.2\%$ inoculum density, reached approximately half of uninoculated plants. Disease severity was much higher at nonsterilized soil than completely sterilized soil. It was determined that the host range of this pathogen includes soybean, peanut, green bean and red bean.

• Journal of Veterinary Clinics
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• v.11 no.1
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• pp.343-346
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• 1994

Microsporum gypseum was identified as the prime cause of dermatitis in two young horses who were housed in unhygienic stables. The lesions were mainly distributed on the thorax, abdomen and rump. The diagnosis was established on the direct demonstration of dermatophyte in the cutaneous lesions and isolation of the fungus in pure and heavy growth from the infected hairs and skin scales on mycological medium at 3$0^{\circ}C$. Microscopoc morphology of the isolate in 'PHOL' stain many macroconidia and few microconidia. Epidemoilogical investigation revealed the prevalence of M. gypseum in the soil of stables. Mycological examination is highly imperative to distinguish the disease from other dermatological disorders. This apperas to be the first report of equine dermatitis due to M. gypseum in Westenn India.

• Biomedical Science Letters
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• v.25 no.4
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• pp.367-371
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• 2019

In this study, the author observed the fungal characteristics of T. verrucosum which is commonly known as the cattle ringworm fungus in the farms of Hoengseong, Gangwon-do. After isolating 20 strains of T. verrucosum from cattle, they were cultured on SDA, PDA media and the fungal characteristics were concluded through visual observation of the colonies, microscopic findings, hair perforation test and urease test. The size of the colonies cultured on SDA media at 37 C was on an average 5 mm at 1 week, 33 mm at 2 weeks, 42 mm at 3 weeks and 58 mm after 4 weeks. Observing the characteristics of the colonies, 17 strains of T. album showing central bold radial folds, 2 strains of T. ochraceum having l throughout the colonies and 1 strain of T. discoides with rapid growth rate and gray-white cotton patterns were found. On microscopic observations of the cultured colonies on SDA, PDA media, macroconidia and microconidia were not found in T. verrucosum and hyphae and chlamydospore were only seen in T. album types. Out of 20 strains of T. verrucosum, hair perforation test was positive on only 3 strains and urease test was positive on all of the 20 strains.