• Research in Plant Disease
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• v.12 no.3
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• pp.290-293
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• 2006

A fruit rot of sweet persimmon(Diospyros kaki cv. 'Fuyu') that infected with blue mold was found during the storage and transport in Jinju Gyeongnam Province, Korea. Fruit surfaces that infected with the fungus were formed water soaked lesion at first then gradually colonized with the fungus and formed mycelial mats. From the point of infection, fruits become sunken and mostly ruptured. The pathogenic fungus was isolated from infected fruits and cultured on potato dextrose agar. The colonies of the pathogenic fungi were white at frist then became greyish green on malt extract agar. Conidia were ellipsoidal and $2.6{\sim}3.8{\times}2.4{\sim}3.8{\mu}m$ in size. Phialides were ampulliform, verticilate of 3-7, $8.0{\sim}9.2{\times}2.0{\sim}3.0{\mu}m$ in size. Metulae were verticils of 2-4, smooth, $9.0{\sim}12.6{\times}3.0{\sim}4.6{\mu}m$ in size. Ramuli were groups 1-3, smooth, $11.0{\sim}17.6{\times}2.3{\sim}3.0{\mu}m$ in size. Rami were groups 1-2, $7.5{\sim}32.6{\times}2.6{\sim}4.2{\mu}m$ in size. Stipes were septate, smooth, thin walled, $56{\sim}302{\times}2.8{\sim}4.0{\mu}m$ in size. Penicilli were mostly quaterverticillate. Based on the cultural and mycological characteristics as well as pathogenicity test on host plants, the fungus was identified as Penicillium expansum. This is the first report on the blue mold of sweet persimmon(Diospyros kaki) caused by P. expansum in Korea.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.187-197
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• 1987

Bacteria and fungi antagonistic to Fusarium oxysporum f. sp. cucumerinum Owen were effectively isolated with each of modified Triple Layer Agar (TLA) technique from rhizosphere soil where cucumber had been grown healthily in plastic film house. Three predominant bacterial isolates selected were identified as Pseudomonas fluorescens, and P. putida, Serratia sp. and three fungal isolates were Gliocladium sp. Trichoderma harzianum, and T. viride. Antagonistic bacteria inhibited $26-45\%$ of germination and $41-56\%$ of germ tube elongation of microconidia of F. oxysporum f. sp. cucumerinum on Water Agar (WA). P. fluorescens was the strongest inhibitor. Several my co parasitisms were observed on dual culture of WA between antagonistic fungi and F. oxysporum f. sp. cucumerinum such as coiling, penetration, overgrowing, and lysis. Mycelial lysis of the pathogen was the most severe at pH 4.6, followed by 3.6, 5.6 and 6.6 of the medium in decreasing order. At pH 6.6, mycelia of the pathogen were not conspicuously damaged, however, the antagonistic fungi formed abundant chlamydospores especially Gliocladium sp. T. harzianum revealed the most excellent antagonism in vitro.

• Research in Plant Disease
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• v.21 no.3
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• pp.208-214
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• 2015

To develop an effective biopesticide to control pepper anthracnose disease, an isolate which showed strong inhibitory effect on the mycelial growth and conidial germination of Colletotrichum acutatum was selected among the antagonistic bacterial isolates collected from pepper grown soil. The bacterial isolate was identified as Bacillus sp. KBC1004 using 16S rRNA sequence analysis. The liquid culture of KBC1004 was freeze-dried and formulated as a wettable powder(WP). The wettable powder form of KBC1004 required at least 24 hours to activate and to inhibit the conidial germination of C. acutatum. In vitro bioassay using the detached green pepper fruits, biocontrol activity of the WP was not recognizable in simultaneous inoculation, but significant disease suppression was observed pre-treatment (24 hr) of the WP before pathogen inoculation. In field experiment, 4 times foliar applications of the 1/500 diluted wettable powder from the end of June showed great control efficacy similar to that of the chemical fungicide application. These results suggest that the formulated WP product could be an alternative mean to control of pepper anthracnose disease in environmentally friendly farming practices.

• Journal of Mushroom
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• v.13 no.3
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• pp.233-236
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• 2015

This report is the result of devising a method for utilizing the device of the load cell to maintain a constant water content of the medium every day to prepare a cultural substrates with the mixer for growing mushrooms bottle cultivation. A load cell was device under the medium mixer. It is developed when the device reaches the weight calculated as amount of substrate bottled and number of the bottle, it is automatically terminated by water injection. In addition, measuring the water content of each medium and the total weight of the medium reaches the target moisture content were calculated by using the program Cheong et al. (2015). Enter the total weight of the medium on the display unit of the load cell, when starting the water supply to reach the weight-based mixing media, the water supply is stopped. This method can improve the convenience by reducing the user's trouble in repeated work medium prepared by automating water supply. The suitable moisture content of the mixed medium for some kind of mushroom can be improved by the composition accuracy. And mycelial culture period, primordial period, mushroom growing period is maintained even of the medium can be produced stably. Therefore, it is possible to achieve a stable management of the mushroom farm according to mushroom quality and quantity stable throughout the year.

• Korean Journal of Medicinal Crop Science
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• v.24 no.5
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• pp.360-369
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• 2016

Background: Cylindrocarpon destructans (Zins) Scholten is an important pathogenic fungus that causes ginseng root rot in many ginseng growing areas in China. Although C. destructans have been studied worldwide, research on its chemotaxis towards ginseng (Panax ginseng C. A. Meyer) root exudates in the rhizosphere remains limited. Methods and Results: In this study, we collected ginseng root exudates with three different polarities from three-year-old ginseng roots, and performed chemotaxis and spore germination assays to investigate the ability of these exudates to induce the response in C. destructans. The results showed that, compared with other conditions, when C. destructans cultivated at $20^{\circ}C$ and a pH of 6 exhibited a strong positive chemotactic response toward $2mg/{\ell}$ aqueous phase, $20mg/{\ell}$ butanol phase, and $0.2mg/{\ell}$ petroleum ether from ginseng root exudates, the chemotactic moving indexes were 0.1581, 0.1638 and 0.1441, respectively. In addition, the spore germination rate with optimal chemotactic parameters were 48%, 53%, and 41% in the aqueous phase, butanol phase and petroleum ether groups, respectiviely, which were significantly higher than that in the control group (23%) (p < 0.05). The mycelial growth rate with optimal chemotactic parameters increased with culture time, and the maximum growth rates in the aqueous phase, butanol phase and petroleum ether groups were 0.425, 0.406 and 0.364 respectively, on the 4th day. The optimal chemotactic parameters were $39.73mg/50mg/{\ell}$, $48.93mg/50mg/{\ell}$, and $31.43mg/50mg/{\ell}$, in aqueous phase, butanol phase and petroleum ether respectively, from ginseng root exudates, compared with $5.5mg/50mg/{\ell}$, in the control group. Conclusions: The present study revealed that certain ginseng root exudates containing chemical attractants act as nutritional sources or signals for C. destructans and support its colonization of ginseng roots.

• The Korean Journal of Mycology
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• v.13 no.3
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• pp.149-156
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• 1985

The study was carried out to find effects of the saponins that were extracted from red ginseng on the growth of, aflatoxins production by, and protein patterns of Aspergillus flavus NRRL 3357. A. flavus with $10^6$ conidia as grown at $30^{\circ}C$ for seven days on the enriched medium. Mycelial growth and pH changes of medium which cultured the mold, were similar to those of the control group. However, aflatoxin which produced by the mold was less than that of the control in all concentration of the saponin. To be more specific, 0.3 % of the saponin inhibited production of aflatoxin $B_1$ and $G_1$ to the extent of 31.6 and 21% of the control. The protein peaks of A. flavus at the fourth day of the culture were shown high intensity near the level of 14,300 daltons. However, the mold which cultured in the medium containing the saponin showed low intensity of protein than that of the control group on all molecular weight.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.96-103
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• 2009

For the control of pathogenic microorganisms, Bacillus spp. were isolated from diseased pepper fruits in Korea. Among them, Bacillus sp. IUB158-03 showed high inhibitory effect on mycelial growth and spore germination of C. gloeosporioides and Botrytis cinerea. The strain was identified as B. amyloliquefaciens IUB158-03 based on its physiological, biochemical characteristics and Microlog analysis. The highest level of antifungal substances by B. amyloliquefaciens IUB158-03 were obtained when the bacterium was cultured in medium containing 2% soluble starch, 3% yeast extract, 0.5% tryptone, 0.5% $NH_4H_2PO_4$, and 1% NaCl (pH 6.0) at $25^{\circ}C$ for 72 hrs. The antifungal substances were purified by butanol extraction, silica gel column chromatography, preparative thin layer chromatography, and high performance liquid chromatography. The purified antifungal substance was confirmed $R_f$ 0.27 by TLC. This substance exhibited antifungal activity against Fusarium solani, Rhizoctonia solani, Botrytis cineria, Alternata alternaria of plant pathogenic fungi and Trichophyton mentagrophytes, Epidermophyton floccosum, Cryptococcus neoformans of human pathogenic fungi.

• Journal of Mushroom
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• v.6 no.3_4
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• pp.121-125
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• 2008

A first, we made white strain 'S line' adaptable to elevated temperature after collected brown strains were characterized with culture characterization on temperature and their monokaryons isolated at the high temperature were crossed with white strain. These S line monokaryons were crossed again with other monokaryons derived from a commercial white. As a result of successive crossing, finally a new variety 'Baengno' was developed. The optimum temperature of mycelial growth was $25^{\circ}C$ but it needed to adjust to $18{\sim}20^{\circ}C$ when incubated at the bottle cultivation. It brought incubation period shortening as 21 days saved 2~3 days when compared with other white varieties. The optimum temperatures of fruiting body initiation and development were almost same to others like as $14^{\circ}C$ and $7^{\circ}C$, respectively. Fruiting body of 'Baengno' was pure white even developed from crossing with brown strains. 'Baengno' was a good variety with high quality and high productivity characterized as quite even budding habit, long stipes and hemi-spherical pilei. This variety needed more air ventilation and had to be adjusted its cultivation environment for the good cultivation.

• Korean journal of applied entomology
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• v.27 no.3
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• pp.149-158
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• 1988

Nematophagous fungi were successfully isolated by baited plating, centrifugation technique of soil, and direct isolation from naturally ingested nematodes. Predominant seven fungi isolated were identified as Artheobotrys arthroboteyides, A.conoides, A. oligospora, Dactylella lobata, Fusatium oxysporum, Monacrosporium ellopsoporum and Harposporium anguillu-lae. Of these, six fungi were tested for cultural characteristics except. H, anguillulae, extre-mely fastidious fungus in artificial media. Among 14 media tested in this experiment, Corn-meal Agar (CMA) and Oatmeal Agar (OMA) were the most suitable media for growing all six nematophagous fungi. Weakly saprophytic M. ellipsospoyum also grew vigoroualy on these two media. The radial growth, dry weight and sporulation of the fungi tested were quite diverse depending on the culture media. D. lobata revealed good growth and abundantly sporulated on Glucoes Peptone Agar (GPA). Although over-all growth of F, oxysporum was not satisfactory on Sucrose Nitrate Agar (SNA), the sporulation was best on this medium. Optimum conditious for mycelial growth and sporulation of nematophagous fungi ranged pH 5-8 and 20-$30^{\circ}C$ on SNA. D. lobata and F, oxysporum grew vigorously and most profusely sporulated on all media tested. They turned out an most promising biocontrol agents for their aggressive growth and sporulation over the ranges of temperature and pH ranges.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.112-118
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• 2006

To select efficient entomopathogenic fungal strains of Lecanicillium for the biocontrol of aphid, Myzus persicae, conidial suspension ($1{\times}10\;conidia/ml$) was sprayed onto a detached Chinese cabbage leaf in a petri dish with a dampened filter paper that had 20 nymphs of aphid. Lecancillium strain 4078 and 6543 were the best strains for the biocontrol of aphid at high temperature of $30^{\circ}C$ and low relative humidity (RH) of 85%, respectively. The cumulative mortality of strain 4078 at $30^{\circ}C$ after 3 days was 100% and that of strain 6543 was 90% at 85% RH after 5 days. Strain 4078 also exhibited almost 100% germination ratio of conidia and high rate of mycelial growth at the broad temperature-range of $15{\sim}25^{\circ}C$. The strain 4078 and 6543 were all identified as Lecanicillium species based on the DNA sequences (accession no.: EF026004 and EF026005, respectively) of the ITS regions of the fungi. Excellent production of aerial conidia of strain 6543 was accomplished by using steamed polished rice as the solid culture medium.