• The Plant Pathology Journal
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• v.25 no.3
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• pp.263-269
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• 2009

Bacterial wilt, Fusarium wilt and Foot rot caused by Ralstonia solanacearum, Fusarium oxysporum, and Phytophthora capsici respectively, continue to be severe problems to tomato, potato and black pepper growers in Vietnam. Three bio-products, Bacillus vallismortis EXTN-1 (EXTN-1), Bacillus sp. and Paenibacillus sp. (ESSC) and Bacillus substilis (MFMF) were examined in greenhouse bioassay for the ability to reduce bacterial wilt, fusarium wilt and foot rot disease severity. While these bio-products significantly reduced disease severities, EXTN-1 was the most effective, providing a mean level of disease reduction 80.0 to 90.0% against bacterial wilt, fusarium wilt and foot rot diseases under greenhouse conditions. ESSC and MFMF also significantly reduced fusarium wilt, bacterial wilt and foot rot severity under greenhouse conditions. Bio-product, EXTN-1 with the greatest efficacy under greenhouse condition was tested for the ability to reduce bacterial wilt, fusarium wilt and foot rot under field condition at Song Phuong and Thuong Tin locations in Ha Tay province, Vietnam. Under field condition, EXTN-1 provided a mean level of disease reduction more than 45.0% against all three diseases compared to water treated control. Besides, EXTN-1 treatment increased the yield in tomato fruits 17.3% than water treated control plants.

• Mycobiology
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• v.31 no.3
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• pp.179-182
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• 2003

A total of 187 endophytic fungi were isolated from 11 plant species, which were collected from 11 locations in Korea. Their antifungal activities were screened in vivo by antifungal bioassays after they were cultured in potato dextrose broth and rice solid media. Antifungal activity against plant pathogenic fungi such as Magnaporthe grisea(rice blast), Corticium sasaki(rice sheath blight), Botrytis cinerea(tomato gray mold), Phytophthora infestans(tomato late blight), Puccinia recondita(wheat leaf rust), and Blumeria graminis f. sp. hordei(barley powdery mildew) was determined in vivo by observing the inhibition of plant disease development. Twenty(11.7%) endophytic fungi fermentation broths were able to control, by more than 90%, at least one of the six plant diseases tested. Among 187 liquid broths, the F0010 strain isolated from Abies holophylla had the most potent disease control activity; it showed control values of more than 90% against five plant diseases, except for tomato late blight. On the other hand, fourteen(7.5%) solid culture extracts exhibited potent disease control values of more than 90% against one of six plant diseases. The screening results of this study strongly suggested that metabolites of plant endophytic fungi could be good potential sources for screening programs of bioactive natural products.

• Journal of Veterinary Science
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• v.22 no.1
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• pp.13.1-13.14
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• 2021

African swine fever (ASF) is one of the most complex infectious swine diseases and the greatest concern to the pig industry owing to its high mortality and no effective vaccines available to prevent the disease. Since the first outbreak of ASF in pig farms, ASF has been identified in 14 pig farms in four cities/counties in South Korea. The outbreak was resolved in a short period because of the immediate control measures and cooperative efforts. This paper reviews the ASF outbreak and the experience of successfully stopping ASF in pig farms in South Korea through active responses to prevent the spread of ASF. In addition, suitable changes to build a sustainable pig production system and collaborative efforts to overcome the dangerous animal disease, such as ASF, are discussed.

• Korean Journal of Veterinary Research
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• v.60 no.2
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• pp.85-88
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• 2020

A 12-month-old domestic rabbit died suddenly without specific clinical signs. Gross examination revealed irregular yellowish hepatic nodules with pus in the submandibular muscles, lungs, uterus, and small intestines. Histopathological examination of the liver showed granulomatous inflammation with acid-fast-positive bacteria. Mycobacterium bovis SB1040 was identified by polymerase chain reaction and spoligotyping, and Pasteurella multocida was isolated from the multiple lesions. This report demonstrates the pathological features of rare bovine tuberculosis (bTB) in a domestic rabbit, the first case in the Republic of Korea. To ensure public safety, we recommend routine monitoring of rabbits to control the incidence of bTB.

• The Plant Pathology Journal
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• v.25 no.4
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• pp.352-360
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• 2009

The potential of three plants extracts, to protect potato plants against bacterial wilt caused by Ralstonia solanacearum was determined under greenhouse and field conditions. All soil drenching treatments of aqueous plant extracts of Hibsicus sabdariffa, Punica granatum and Eucalyptus globulus significantly reduced the disease severity compared with inoculated control. Although the applications of all three plant extracts resulted in similar reductions of disease severity in field up 63.23 to 68.39%, treatment of E. globulus leaf extract was found greater in restricting the symptom development than other the two plant extracts in the greenhouse. More than 94% reduction in the bacterial wilt symptom was observed in potato plants. All tested plant extracts were effective in inhibiting the growth of bacterial pathogen, not only in vitro, but also in stem of potato plants as compared with the inoculated control Potato plants treated with extract of H. sabdariffa reduced bacterial growth more effectively than treatment with P. granatum and E. globulus. Activity of defence-related enzymes, including peroxidase, polyphenoloxidase and phenylalanine ammonia lyase, were significantly increased in plants treated with the plant extracts compared to the control during the experimental period. In general, the higher enzymes activities were determined in both inoculated and non-inoculated treated potato plants after 8 days from plant extracts treatment. These results suggested that these plant extracts may be play an important role in controlling the potato bacterial wilt disease, through they have antimicrobial activity and induction of systemic resistance in potato plants.

• The Plant Pathology Journal
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• v.29 no.2
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• pp.136-143
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• 2013

Microbial communities that are associated with plant roots are highly diverse and harbor tens of thousands of species. This so-called microbiome controls plant health through several mechanisms including the suppression of infectious diseases, which is especially prominent in disease suppressive soils. The mechanisms implicated in disease suppression include competition for nutrients, antibiosis, and induced systemic resistance (ISR). For many biological control agents ISR has been recognized as the mechanism that at least partly explains disease suppression. Implications of ISR on recruitment and functioning of the rhizosphere microbiome are discussed.

• Research in Plant Disease
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• v.9 no.2
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• pp.72-78
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• 2003

Eight fungicides including prochloraz, tebuconazole, benomyl, mancozeb, thiophanate-methyl, azoxystrobin, and fluazinam were examined for their control effects on Fusarium bulb and root rot of oriental orchid, Cymbidium goeringii. Among the chemicals, prochloraz and tebuconazole were the most effective on suppression of the causal pathogen, F. oxysporum in vitro and on control of the disease in vivo. Prochloraz and tebuconazole inhibited mycelial growth of the fungi 95~100% at 10ppm a.i. and microconidial germination 75~100% at 100ppm a.i. Prochloraz and tebuconazole showed 80~92% and 84~88% protective control value on the disease, respectively. However, curative effects on infected orchid were relatively low. Other chemicals showed no or lower than 20% curative and 50% protective control value. Results indicated that prochloraz and tebuconazole can be used for the control of the Fusarium bulb and root rot of oriental orchids. However, the chemicals need to be applied prior to the disease development to achieve successful control efficacy.

• Korean Journal of Veterinary Research
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• v.58 no.3
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• pp.125-129
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• 2018

We investigated the prevalence of canine brucellosis in companion and stray dogs between March 2015 and December 2016 and determined the disease characteristics based on the geographic distribution, sex and age of the dogs in South Korea. We conducted a large-scale survey using serological and bacteriological tests. Samples were collected from 2,394 dogs (1,825 companions and 569 strays). Thirty (1.3%) samples were positive for Brucella canis antibodies including 16 (0.9%) from companion dogs and 14 (2.5%) from stray dogs. Two (1.0%) of the 196 samples cultured from the stray dogs were positive. When compared with male dogs, the female companion and stray dogs had a significantly higher prevalence of brucellosis. Moreover, the prevalence of canine brucellosis was significantly higher in stray dogs older than 6 years and the prevalence of the disease in companion dogs was highest in Incheon (2.1%) and Jeolla (2.1%) provinces. Stray dogs from the Daejeon metropolitan area had the highest prevalence of brucellosis (7.9%). National control measures for canine brucellosis have not previously been implemented. Our findings suggest that appropriate screening tests and control measures are necessary to improve the health of dogs and to protect public health in Korea, particularly with the rapid growth of the companion animal industry.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.199-204
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• 2009

Three plant growth-promoting yeasts and two rhizobacteria were tested for controlling tomato wilt caused by Fusarium oxysporum f. sp. lycopersici under green-house and field conditions. Under greenhouse and field conditions, all treatments were significantly reduced disease severity of tomato wilt relative to the infected control. The highest disease reductions in pots (75.0, 67.4%) and field (52.5, 42.4%) were achieved by Azospirillum brasilense and Bacillus subtilis compared to infected control. Under field condition all treatments produced the highest tomato yield compared to the control plants inoculated with the pathogen.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.278-282
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• 2006

Bacillus vallismortis EXTN-1, a biocontrol agent in cucumber, tomato and potato was tested in rice pathosystem against rice fungal pathogens viz. Magnaporthe grisea, Rhizoctonia solani and Cochliobolus miyabeanus. Apart from increasing the yield in the bacterized plants (11.6-12.6% over control), the study showed that EXTN1 is effective in bringing about disease suppression against all the tested fungal pathogens. EXTN-l treatment resulted in 52.11% reduction in rice blast, 83.02% reduction in sheath blight and 11.54% decrease in brown spot symptoms. As the strain is proven as an inducer for systemic resistance based on PR gene expression in Arabidopsis and tobacco models, it is supposed that a similar mechanism works in rice, bringing about disease suppression. The strain could be used as a potent biocontrol and growth-promoting agent in rice cropping system.