• The Korean Journal of Mycology
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• v.24 no.1 s.76
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• pp.56-66
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• 1996

Ecological variations of Arbuscular mycorrhizal (AM) fungi were determined from the soils collected from different sites of the polluted and unpolluted areas related to the soil pollutions. Average 24.5 spores $(per\;20g)^{-1}$ soil of AM fungal spore were counted from the 32 sites of soils collected from On-san (polluted), whereas average 4.1 spores $(per\;20g)^{-1}$ soil from the 18 sites of those from Mt. Kwanak (polluted); Average 23.6 spores $(per\;20g)^{-1}$ soil of AM fungal spore were also counted from the 30 sites of soils collected from Chung-mu (unpolluted), whereas average 15.8 spores $(per\;20g)^{-1}$ soil from the 14 sites of those from Mt. Chungwang (unpolluted).The spores of AM fungi were the species of Glomus, Gigaspora, Acaulospora and Scutellospora. Among the above four genera, the species of Glomus were observed to be more abundant than the other genera in the soils collected from On-san, Chung-mu and Mt. Chungwang whereas the species of Gigaspora in those from Mt. Kwan-ak. The parameters of soils measured showed some variations between the polluted and unpolluted areas; 12.9 to 16.4% in the soil moisture, 5.6 to 8.3% in the organic matter and 4.3 to 5.7 at soil pH (polluted to unpolluted areas, respectively). The soils collected, thereby, appeared to be more strongly acidic and also lower in the contents of soil moisture or organic matter at the polluted area than unpolluted area. Based on the ecological criteria, the species richness or species diversity had significant differences (p<0.05) between polluted and unpolluted area. The spore density of genus Glomus or Gigaspora was significantly different (p<0.05) among the soils of three different plant vegetations (conifer plants, broad leaf plants, and grass plants). Also, there were significant differences (p<0.05) in the species evenness or species diversity among the soils referring to three different plant vegetations. There was a direct relationship $(r^2=0.38)$ between soil moisture and organic matter measured from 94 soil samples. Since there was a direct relationship $(r^2=0.22)$ between organic matter and total spores, it seems to be likely to presume that mycorrhizal spores can be increased in proportion to enhanced organic matters in soils. The species richness or species diversity was inclined to increase in proportion to enhanced soil pH and total spores in soils.

• The Korean Journal of Mycology
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• v.8 no.3
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• pp.159-166
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• 1980

Aspergillus niger van Tieghem was cultured by the method of submerged and synchronized culture for the study of differentiation. Acid-phenol soluble cell proteins of the fungus were extracted from four stages during development. Those acid-phenol soluble proteins were separated by polyacrylamide gel electrophoresis to determine the protein patterns. A new protein band was observed from the pre-sporulation body, color density of the stained protein bands in four tubes differed according to the differentiation stages. The number of protein bands in 10% gels varied from 18 to 16, 17, and 19 according to the course of spore germination stage, conidiophore stage, phialide maturation stage and sporulation stage.

• KSBB Journal
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• v.28 no.6
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• pp.400-407
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• 2013

The growth characteristics and production of color pigments by Monascus strains were investigated during liquid culture, and production of monacolin K in red mold rice was carried out by solid state fermentation. Four different Monascus ruber strains were cultured in potato dextrose yeast extract broth (PDYB) media at $25^{\circ}C$ for 15 days. The high producing strain for red pigment was not corresponded to the strain for yellow pigment. Production of red pigment was high in the strain causing the fast pH change in culture broth. Production of monacolin K in red mold rice by solid state fermentation was influenced by a combination of wet cell weight and spore density in inoculum by liquid culture. Most strains showed the high production of monacolin K in red mold rice, when submerged fermentation was carried out for 5 days as inoculum for solid state fermentation. These results suggest that submerged fermentation period of inoculum have an effect on the production of monacolin K in red mold rice by solid state fermentation, and monacolin K in red mold rice could be increased by controlling the condition of submerged fermentation for inoculum.

• The Plant Pathology Journal
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• v.32 no.6
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• pp.508-518
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• 2016

Early blight of tomato caused by Alternaria solani, is responsible for severe yield losses in tomato. The conidia survive on soil surface and old dry lower leaves of the plant and spread when suitable climatic conditions are available. Macroclimatic study reveals that highest inoculum concentration of Alternaria spores appeared in May 2012 to 2013 and lowest concentration during January 2012 to 2013. High night temperature positively correlated and significantly (P < 0.01) involved in conidial spore dispersal and low relative humidity (RH) displayed significant (P < 0.05) but negative correlation with conidial dispersal. The objective of the study was to modify microclimatic conditions of tomato crop canopy which may hamper conidial dispersal and reduce disease severity. We evaluated effect of marigold intercropping and plastic mulching singly and in consortia on A. solani conidial density, tomato leaf damage and microclimatic parameters as compar to tomato alone (T). Tomato-marigold intercropping-plastic mulching treatment (T + M + P) showed 35-39% reduction in disease intensity as compared to tomato alone. When intercropped with tomato, marigold served as barrier to conidial movement and plastic mulching prevented evapotranspiration and reduced the canopy RH that resulted in less germination of A. solani spores. Marigold intercropping and plastic mulching served successfully as physical barrier against conidial dissemination to diminish significantly the tomato foliar damage produced by A. solani.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.48-48
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• 2014

Arbuscular Mycorrhizal Fungi(AMF) is widespread symbiont forming mutualistic relationship with plant root in terrestrial forest in ecosystem. They provide improved absorption of nutrient and water, and enhance the resistance against plant pathogen or polluted soil, therefore AM fungi are important for survival and maintaining of individual or community of plant. For last decade, many studies about the functional variation of AM fungi on host plant growth response were showed that different geographic isolates, even same species, have different effect on host plant. However, little was known about functional variation of AM fungal isolates originated single population, which provide important insight about intraspecific diversity of AMF and their role in forest ecosystem. In this study, four AM fungal isolates of Rhizophagus clarus were cultured in vitro using transformed carrot (Daucus carota) root and they showed the difference between isolates in ontogenic characteristics such as spore density and hyphal length. The plant growth response by mycorrhizas were measured also. After 20 weeks from inoculation of these isolates to host plants, dry weight, Root:Shoot ratio, colonization rates and N, P concentration of host plant showed host plant was affected differently by AM fungal isolates. This results suggest that AM fungi have high diversity in their functionality in intraspecific level, even in same population.

• Analytical Science and Technology
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• v.26 no.4
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• pp.262-267
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• 2013

Gravitational field-flow fractionation (GrFFF) is a separation technique that utilizes earth's gravity as the external field. GrFFF is a convenient tool for the size and/or density-based separation of micron-sized particles of various origins. In this study, GrFFF was employed for size-based separation of oyster mushroom spores. Oyster mushroom spores have smooth surface and are of cylindrical to narrow kidney-shapes with 5 to 12 im in longer dimension and 3 to 4 im in shorter dimension, as was confirmed by optical microscope (OM). GrFFF conditions were optimized for separation and characterization of spores by varying the channel flow rate from 0.5 to 1 mL/min. During the GrFFF elution of the spores, 3 fractions were collected to confirm the growth of oyster mushroom spore. The collected fractions were incubated for 30 days in water to examine the influence of the size on the growth of the spores. Results suggested that the oyster mushroom spores collected at the middle part of the GrFFF fractogram grew faster than those collected at the beginning or at the end of the fractogram.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.1-5
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• 2010

Enterocytozoon bieneusi, a microsporidian species, has emerged as an opportunistic pathogen in AIDS patients. This organism has also been identified in a wide range of animals, and the zoonotic potential of human infections is of particular interest. This study revealed that this organism was found with relatively high prevalence in feces of asymptomatic cattle in Korea. Fecal specimens were obtained from a total of 1,720 cattle in a slaughterhouse located in Chungnam province, Daejeon city and Chonbuk province. After removal of fecal debris by sieving and density gradient centrifugation, samples were examined by microscopic examination and then nested polymerase chain reaction (PCR). Microscopic examination with the modified trichrome staining for the fecal specimens revealed 194 (11.28%) positive calves for microsporidia spore. PCR using the specific primer for E. bieneusi revealed 79 (4.59%) positive calves. The infection ratio of microsporidia was higher in March than other season.

• The Korean Journal of Mycology
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• v.10 no.2
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• pp.57-65
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• 1982

Highly phosphorylated nucleotides were investigated to assure whether the eucaryotic Aspergillus niger produce these substances or not during the differentiation. Investigation was extended to see how organic phosphate interacts with inorganic polyphosphate during development, and high molecular weight RNA-polyphosphate complex was detected in 2.6% polyacrylamide gel by electrophoresis. Guanosine tetraphosphate was found in vesicle and phialide forming mycelia and spore forming body by PEI cellulose TLC. It is revealed that guanosine tetraphosphate is a common substance for spore formation in eucaryotic microorganisms as well as in procaryotic. Especially, prior to sporulation, protein bound RNA and protein bound phosphate may occur as a result of reorganization of cellular materials. The evidence was obtained by the fact of differential increase of optical density ratio between the samples from different developmental stages of this fungus. In 2.6% polyacrylamide gel which was run to electrophoresis, high molecular weight RNA (mostly rRNA) was found to couple and to make RNA-polyphosphate complex. The complex was examined with enzymes and radioactive isotope of $^{32}P$. (enzymic test was not reported here.) RNA-polyphosphate complex might be another sort of highly phosphorylated nucleotide or rRNA beside guanosine-tetraphosphate.

• Research in Plant Disease
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• v.29 no.1
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• pp.11-22
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• 2023

Resazurin-based microtiter assay was used to evaluate the inhibitory effect of fungicides on the respiration of Colletotrichum acutatum s. lat. 20JDS8 sensitive and 20CDJ6 resistant to strobilurin fungicides. The spores of C. acutatum s. lat. 20JDS8 were inoculated into potato dextrose broth (PDB) at densities of 1x10⁴, 1x10⁵ and 1x10⁶ spores/ml, respectively. The relative fluorescence unit (RFU) of all treatments inoculated at each spore density started to rise after 12 hr of incubation, and were 1,965.5, 5,412.5, and 10,061.0, respectively, after 24 hr of incubation. To evaluate the inhibitory effect of fungicide on the respiration of the pathogen, the spores of the pathogen were inoculated into the PDB and treated with the fungicides 0, 6, 12, and 24 hr after incubation, respectively. After keeping the pathogen culturing for another 24 hr, PrestoBlue reagent was treated into the PDB culturing the pathogen. The RFU of each treatment was examined 1 hr after the reagent was treated. When dithianon, isopyrazam, pyraclostrobin, and fluazinam were treated at high concentrations in the stages of spores (immediately after inoculation [0 hr]), spore germination (after incubation for 6 hr), and hyphal growth (after incubation for 12 hr), the respiration of pathogens was inhibited by 90-100%. When the fungicides were treated after culturing the pathogen for 24 hr, the respiratory inhibitory effects were greatly reduced. With pyraclostrobin-resistant C. acutatum s. lat. 20CDJ6, azxoystrobin, trifloxystrobin and kresoxim-methyl, which have the same mode of action, had very little or no respiratory inhibitory effect in all growth stages of pathogens. Based on the above results, it was thought that the resazurin-based microtiter assay could quickly and accurately evaluate the inhibitory efficacy of the fungicides that inhibited respiration.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.225-233
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• 1991

This study was conducted to evaluate the potential of indigenous vesicular-arbuscular mycorrhizal fungi(VAMF) in the rhizosphere soil of horticultural crops grown under greenhouse and open-field condition, in the southern area of Kores. Soil samples collected from the rhizosphere of some sellected horticultural crops, such as cucumber, hot pepper, lettuca, tomato and eggplant grown under greenhouse or open-field condition. All tested crops are considered as mycorrhizal plants. The infection rate of horticultural crops investigated ranged from 38% to 70%, hot pepper and eggplant grown under greenhouse condition showed the highest infection being 66.0% and 70.0%, respectively. Spore densities were from 4.8 to 20.0g-1 on dried soil basis. Spore densities of VAMF in the rhizosphere soils under greenhouse condition were higher than that of open-field conditions. The highest distribution of spores in diameter ranged from $75{\mu}m$ to $106{\mu}m$ in the rhizosphere soil of lettuce, cucumber and tomato while those in hot pepper and eggplant ranged from $75{\mu}m$ to $250{\mu}m$. Glomus sp.-type spores predominated in the slightly acid soil(pH 6.3), while Acaulospora sp.-type spores greatly predominated in the very strongly acid field(pH 4.9).