• The Korean Journal of Mycology
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• v.14 no.2
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• pp.109-119
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• 1986

The correlations between environmental influences on microorganisms in soil and its effects on disease development in ginseng field were studied to obtain some useful data for increasing ginseng production and effective preventive measures against the root rot caused by soil-borne pathogens. The diseased replanted ginseng fields were selected as the diseased field and the healthy plot in first planted field selected as control in three major Korean ginseng producing areas such as Kumsan, Goesan and Poonggi. The physicochemical characteristics of the soil were analyzed and microorganisms susceptible for root rot of ginseng, such as Fusarium spp. and general fungi were investigated for their population density in various soil conditions. Correlations between soil microbial populations and environmental factors were investigated. The numbers of Fusarium spp. propagules were abundant in fall in both soil conditions. The numbers of Fusarium spp. were 1.9 to 2.6 times higher in replanted field than first planted field except Goesan area. Relative ratio of Fusarium spp. to total fungi propagules in replanted field was 1.6 times higher in replanted field than first planted field indicating higher numbers of Fusarium spp. distributed in replanted field of soil. The numbers of propagules of total fungi were increased in June and July and there was no sensitive variation according to the temperature. There was no significant difference in vertical distributions of total fungi according to soil depth, while the total fungi were abundant in the surface layer and $10{\sim}15\;cm$ layer. The contents of organic matter and phosphate in healthy field were somewhat high, and phosphate/organic matter ratio and Mg contents were high in diseased field. All of the soils showed a weak acidic pH of 4.5 to 5.7. Soil moisture contents were increased during winter season, but did not show any significant changes during the growing periods, showing 24.6% in healthy field and 19.5% in diseased field respectively. Soil temperature was the highest in July and August and the lowest in January and February.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.315.2-315
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• 1995

No Abstract, See Full Text

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.531-535
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• 1998

This study was conducted to test the effect of chitosan, grape fruit seed extracts(GFSE) and sodium hypochloride gas on the control of mycotoxin producing pathogens occurred kin postharvest grains. Among the treatments, sodium hypochloride gas showed the highest control effect on wheat, soybean and corn see maintained in natural conditions after postharvest and GFSE had a little control effect, but chitosan treatment had no effect. Sodium hypochloride gas exhibited the strongest control effect on the major mycotoxin producing pathogens such as Penicillium spp. Aspergillus spp. and Fusarium spp., whereas GFSE had a little control effect. Sodium hypochloride gas appeared to be effective when the grains were treated with this gas more than 24 hours.

• Journal of Ginseng Research
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• v.26 no.3
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• pp.151-158
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• 2002

Ginseng (Panax quinquefolius L.) has become one of the most valuable herb crops grown in North America. However, traditional cropping practices are favourable to disease and significant losses due to root disease are common, despite frequent use of fungicides. Seedlots are often contaminated with pathogens, however, little is known about the causes of seed decay and the role of seed pathogens as incitants of root rots. It was shown that both Fusarium spp. and Cylindrocarpon destructans were able to rot seeds and that C. destructans was more virulent than Fusarium spp. on seedling roots. A modified rose bengal agar MRBA) medium (1 g KH$_2$PO$_4$; 0.5 g MgSO$_4$; 50 mg rose bengal; 10 g dextrose; 5 g Bacto peptone; 15 g Bacto agar; 30 mg streptomycin sulfate; 250 mg ampicillin; 10 mg rifampicin; 500mg pentachloronitrobenzene; 500 mg dicloran; and 1 L distilled water) was superior to potato dextrose agar in detecting C. destuctans in diseased roots. Isolation of C. destructans from diseased seedlings arising from seeds sown in replant soil supported the hypothesis that this pathogen is a cause of ginseng replant failure in North America.

• Mycobiology
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• v.43 no.3
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• pp.343-346
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• 2015

In 2006~2010, leaf spot symptoms, that is, small, yellow spots that turned into dark brown-to-black lesions surrounded by a yellow halo, were observed on Cymbidium spp. in Gongju, Taean, and Gapyeong in Korea. A Fusarium species was continuously isolated from symptomatic leaves; in pathogenicity testing, isolates caused leaf spot symptoms consisting of sunken, dark brown lesions similar to the original ones. The causal pathogen was identified as Fusarium subglutinans based on morphological and translation elongation factor 1-alpha sequence analyses. This is the first report of F. subglutinans as the cause of leaf spot disease in Cymbidium spp. in Korea.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.85-92
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• 2012

To elucidate the mycotoxin production of Penicillium, Aspergillus and Fusarium spp. isolated from round bale silage, TLC analysis of culture filtrates were conducted. Mycotoxin citrin and patulin were detected from culture filtrates of Penicillium paneum. Aflatoxin was detected from culture filtrates of Aspergillus flavus. Gliotoxin are known to produce by A. fumigatus was not detected. Mycotoxins produces by Fusarium spp., Fumonisin, zearalenone and deoxynivalenol was not detected in the culture filtrates of Fusarium proliferatum.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.25-25
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• 2014

Three species of Fusarium, F. fujikuroi, F. verticillioides and F. proliferatum, are known to be associated with bakanae disease of rice [1, 2]. F. fujikuroi infects rice flowers and survive in endosperm and embryo of the seeds. Infected seed is an important source of primary inoculum of pathogens [3]. Seeds of rice (Oryza sativa cv. Boramchan) collected from bakanae-infected field were found to be 96% infected with Fusarium sp., 52% with F. fujikuroi, 42% with F. verticillioides, and 12% with F. proliferatum as determined by incubation method and species-specific PCR assays. F. fujikuroi was detected at lemma/palea, endosperm and embryo whereas F. verticillioides and F. proliferatum were recovered only from lemma/palea by means of component plating test. Seed disinfection methods have been developed to control bakanae disease and prochloraz has been most widely used for rice seeds. Two chemicals formulated with prochloraz (PC 1) and prochloraz + hexaconazole (PC 2) that inhibit biosynthesis of ergosterol strongly reduced the incidence of Fusarium spp. on selective media to 4.7% and 2.0%, respectively. Disease symptoms of rice seedlings in nursery soil were alleviated by chemical treatment; seedlings with elongated leaves or wide angle between leaf and stem were strikingly reduced from 15.6 to 3.2% (PC 1) and 0 (PC 2), stem rots were reduced from 56.9 to 26.2% (PC 1) and 32.1% (PC 2), and normal seedling increased from 0.4 to 13.3% (PC 2). Prochloraz has some disadvantages and risks such as the occurrence of tolerant pathogens [4] and effects on the sterol synthesis in animals and humans [5]. For these reasons, it is necessary to develop new disinfection method that do not induce fungal tolerance and are safe to humans and animals. Chlorine dioxide ($ClO_2$), that is less toxic, produces no harmful byproducts, and has high oxidizing power, has been reported to be effective at disinfection of several phytopathogenic fungi including Colletotrichum spp. and Alternaria spp. [6]. Gaseous $ClO_2$ applied to rice seeds at a concentration of 20 ppm strongly suppressed mycelial growth of Fusarium fujikuroi, F. verticillioides and F. proliferatum. The incidence of Fusarium spp. in dry seed with 8.7% seed moisture content (SMC) tended to decrease as the concentration of $ClO_2$ increased from 20 to 40 ppm. Applying 40 ppm $ClO_2$ at 90% relative humidity, incidence was reduced to 5.3% and resulted in significant reduction of disease symptoms on MS media. In nursery soil, stem rot was reduced from 56.9 to 15.4% and the number of normal seedlings increased from 0.4 to 25.5%. With water-soaked seeds (33.1% SMC) holding moisture in the endosperm and embryo, the effectiveness of disinfection using $ClO_2$ increased, even when treated with only 20 ppm for four hours. This suggests that moisture was a key element for action of $ClO_2$. Removal of the palea and lemma from seeds significantly decreased the incidence of Fusarium spp. to 3.0%. Seed germination appeared to decrease slightly by water-soaking at $30^{\circ}C$ because of increased SMC and by physical damage of embryos from hulling. These results indicate that the use of gaseous $ClO_2$ was effective as a means to disinfect rice seeds infected with Fusarium spp. and that moisture around the pathogens in the seed was an important factor for the action of $ClO_2$. Further investigations should be conducted to ascertain the best conditions for complete disinfection of Fusarium spp. that infect deep site of rice seeds.

• Korean Journal of Organic Agriculture
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• v.29 no.4
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• pp.561-574
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• 2021

This study was conducted to evaluate the control efficacy of the organic farming materials (OFMs) on tuber rot of Gastrodia elata caused by Fusarium spp. The antifungal activities in vitro as well as the suppressive effect of 15 OFMs on the spore germination and germ tube growth by inoculating spore suspension on immature tubers in vivo were investigated. 7 OFMs inhibited the mycelial growth of Fusarium spp. and 7 of them were microbial agents. In the screening using immature tubers, 3 OFMs were very effective with control efficacy value of 70%. Among them, sulfur provided suppressive effect on both mycelial growth and spore germination against tuber rot of G. elata. Finally, 3 OFMs were selected to test the protective and curative effects, and all chosen OFMs significantly suppressed disease incidence when applied in the preventive action, in comparison with the curative action. Especially, sulfur and Bacillus subtilis gave excellent protective control efficacy with control values of 93.2% and 86.9%, respectively, whereas its curative control effect was relatively low (73.3%, 60.2%). On the other hand, the preventive and curative effects of citronella + paraffin oil + ethyl alcohol were 73.3% and 67.0%, respectively. This study suggests that tuber rot of G. elata can be controlled by some OFMs in the rain shelter greenhouse under continuous cultivation condition and protective treatment is more important and efficient.

• Food Science and Preservation
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• v.24 no.6
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• pp.857-864
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• 2017

To establish good storage practices for hulled barley against mycotoxin contamination, we measured occurrence of fungi and mycotoxin in hulled barley grains under various storage conditions. Hulled barley grains collected from two places were stored in five different warehouses: 1) two without temperature control, 2) one with temperature controlled at $12^{\circ}C$, 3) a chamber set at $15^{\circ}C/65%$ relative humidity, and 4) one seed storage set at $10^{\circ}C$. The samples were stored for six month with temperature and relative humidity monitored regularly. Every stored samples were retrieved after 0, 1, 3, and 6 month to investigate fungal and mycotoxin contamination. From the stored grains, Fusarium, Epicoccum, Alternaria, and Drechslera spp. were frequently detected. In the warehouses without temperature control, Fusarium and Alternaria spp. constantly decreased, whereas Drechslera spp. increased along with storage period. In the other warehouses with temperature controlled, Fusarium spp. decreased slowly and more than 2.5 log CFU/g of Fusarium spp. were detected after 6 month storage. The level of nivalenol was maintained during 0-3 month but increased after 6 month storage. There was no difference in the nivalenol levels between the warehouses. Therefore reducing storage period less than 6 months could be more effective to control nivalenol contamination in hulled barley grains.

• Journal of environmental and Sanitary engineering
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• v.20 no.2 s.56
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• pp.29-32
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• 2005

We just carried out this study in order to obtain an appropriate information of the population of toxigenic fungi in crude drugs in seoul. Results of fungal examination on twenty-three kinds crude drugs were described in this report. In 21 crude drugs, colonies of fungi were possible to identify into 7 genera. Predominant genera of fungi in crude drugs were Aspergillus spp. $(14,\;46.6\%)$, Scopulariospsis spp. $(7,\;23.3\%)$, Penicillium spp., Rhizopus spp., Fusarium spp $(2,\;6.6\%,\;respectively)$ and Phoma sp., Chaetomium sp. $(1,\; 3.3\%,\;respectively)$. Mycotoxin producing fungi like Aspergillus spp., Penicillum spp., and Fusarium spp. were 18 colonies$(60\%)$, totally.