• 농약과학회지
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• 제19권1호
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• pp.47-53
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• 2015

딸기에는 여러 가지 병이 발생하여 경제적으로 막대한 손실을 유발하며 많은 양의 농약이 사용되고 있는 실정이다. 최근 유기농산물과 식품안전성에 관한 소비자의 관심이 증가함에 따라 화학농약 대체제에 의한 병해 방제법 개발이 다각적으로 시도되고 있다. 본 연구에서는 광범위 소독제로 사용하고 있는 NaDCC의 딸기 주요 병원균(딸기 시들음병, 딸기 탄저병, 딸기 역병 그리고 딸기 세균성모무늬병)에 대한 항균활성 및 방제효과를 검증하고, 친환경제제로의 가능성을 확인하고자 수행되었다. NaDCC는 150~300 ppm 농도로 처리했을 때 병원진균의 균사생장을 효과적으로 억제하였고, 포자 발아율도 68% 이상 경감시키는 것으로 조사되었다. NaDCC는 딸기 세균성모무늬 병원균에 대하여서도 우수한 방제효과를 나타내었는데, 포장조건에서 딸기 세균성 모무늬병의 발생을 50% 감소시키는 것으로 나타났다. 이상의 결과를 토대로 NADCC는 딸기 병 방제용 방제제 후보물질로 사용될 수 있을 것으로 생각되었다.

• 식물병연구
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• 제9권4호
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• pp.213-216
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• 2003

2002년 봄, 순천시 비닐 하우스에서 육묘중인 차나무에 세균병이 발견되었다. 초기 병반은 신엽에 작은 수침상 병반이 나타났으며 갈색반점으로 변하였다. 이 병반은 점점 커졌으며, 중륵 또는 엽맥을 따라 신장하였으며 검은색으로 변하였고, 병든 잎은 쉽게 낙엽이 되었다. 병반으로부터 10균주를 분리하여 잎에 접종한 결과 자연 병반과 동일한 병징이 나타났다. 병원세균은 염색반응, 형태적 특성, colony 패턴, 생리적, 생화학적 반응에 따라 Pseudomonas syringae pv. theae로 동정되었다. 국내에서 이 균에 의한 차나무 세균병은 아직 보고되지 않았으므로 병명을 차나무 갈색마름병(brown blight)으로 명명할 것을 제안한다.

• 원예과학기술지
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• 제19권1호
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• pp.7-11
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• 2001

1998-1999년도에 걸쳐 총 238점의 고추 유전자원에 대하여 흰가루병에 대한 저항성을 검정한 결과, Capsicum baccatum에 속하는 KC604, 605, 606, 608, C. chinense에 속하는 KC616, C. pubescens에 속하는 KC638, 640, 641, 642, 643, 644가 발병하지 않을 정도로 고도의 저항성을 나타내었으며 C. annuum에 속하는 KC47-1(PI244670), KC319-1, KC545, KC320는 경미하게 발병하여 다소 저항성으로 나타났다. KC47-1, KC319-1, KC320은 Stemphylium spp.에 의한 고추 잎점무늬병에 저항성이며, 그 중 KC 47-1은 더뎅이병(Xanthomonas campestris pv. vesicatoria)에도 저항성이어서 이들 병에 복합저항성 육성도 가능할 것으로 기대된다.

• The Plant Pathology Journal
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• 제37권3호
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• pp.215-231
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• 2021

Brown leaf spot disease caused by Nigrospora guilinensis on Phellodendron chinense occurs in a large area in Dayi County, Chengdu City, Sichuan Province, China each year. This outbreak has severely reduced the production of Chinese medicinal plants P. chinense and caused substantial economic losses. The bacterial isolate JKB05 was isolated from the healthy leaves of P. chinense, exhibited antagonistic effects against N. guilinensis and was identified as Bacillus megaterium. The following fermentation medium and conditions improved the inhibitory effect of B. megaterium JKB05 on N. guilinensis: 2% glucose, 0.1% soybean powder, 0.1% KCl, and 0.05% MgSO₄; initial concentration 6 × 10⁶ cfu/ml, and a 42-h optimal fermentation time. A composite of 0.1% nano-SiO₂ JKB05 improved the thermal stability, acid-base stability and ultraviolet resistance by 16%, 12%, and 38.9%, respectively, and nano-SiO₂ was added to the fermentation process. The best formula for the wettable powder was 35% kaolin, 4% polyethylene glycol, 8% Tween, and 2% humic acid. The following quality test results for the wettable powder were obtained: wetting time 87.0 s, suspension rate 80.33%, frequency of microbial contamination 0.08%, pH 7.2, fineness 95.8%, drying loss 1.47%, and storage stability ≥83.5%. A pot experiment revealed that the ability of JKB05 to prevent fungal infections on P. chinense increased considerably and achieved levels of control as high as 94%. The use of nanomaterials significantly improved the ability of biocontrol bacteria to control this disease.

• The Plant Pathology Journal
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• 제38권3호
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• pp.182-193
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• 2022

Turfgrass, the most widely grown ornamental crop, is severely affected by fungal pathogens including Sclerotinia homoeocarpa, Rhizoctonia solani, and Magnaporthe poae. At present, turfgrass fungal disease management predominantly relies on synthetic fungicide treatments. However, the extensive application of fungicides to the soil increases residual detection frequency, raising concerns for the environment and human health. The bacterial volatile compound, 2,3-butanediol (BDO), was found to induce plant resistance. In this study, we evaluated the disease control efficacy of a combination of stereoisomers of 2,3-BDO and commercial fungicides against turfgrass fungal diseases in both growth room and fields. In the growth room experiment, the combination of 0.9% 2R,3R-BDO (levo) soluble liquid (SL) formulation and 9% 2R,3S-BDO (meso) SL with half concentration of fungicides significantly increased the disease control efficacy against dollar spot and summer patch disease when compared to the half concentration of fungicide alone. In field experiments, the disease control efficiency of levo 0.9% and meso 9% SL, in combination with a fungicide, was confirmed against dollar spot and large patch disease. Additionally, the induction of defense-related genes involved in the salicylic acid and jasmonic acid/ethylene signaling pathways and reactive oxygen species detoxification-related genes under Clarireedia sp. infection was confirmed with levo 0.9% and meso 9% SL treatment in creeping bentgrass. Our findings suggest that 2,3-BDO isomer formulations can be combined with chemical fungicides as a new integrated tool to control Clarireedia sp. infection in turfgrass, thereby reducing the use of chemical fungicides.

• 한국축산식품학회지
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• 제34권5호
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• pp.614-621
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• 2014

This study was conducted to isolate and characterize bacteriocin-producing bacteria against Clostridium perfringens (C. perfringens) from domestic animals to determine their usefulness as probiotics. Bacteriocin-producing bacteria were isolated from pig feces by the spot-on-lawn method. A total of 1,370 bacterial stains were isolated, and six were tentatively selected after identifying the inhibitory activity against the pathogenic indicator C. perfringens KCTC 3269 and KCTC 5100. The selected strains were identified as Enterococcus faecalis (E. faecalis) by 16s rRNA sequencing. Most of the isolated bacterial strains were resistant to 0.5% bile salts for 48 h and remained viable after 2 h at pH 3.0. Some E. faecalis also showed strong inhibitory activity against Listeria monocytogenes KCTC 3569, KCTC 3586 and KCTC 3710. In the present study, we finally selected E. faecalis AP 216 and AP 45 strain based on probiotic selection criteria such as antimicrobial activity against C. perfringens and tolerance to acid and bile salts. The bacteriocins of E. faecalis AP 216 and AP 45 strains were highly thermostable, showing anticlostridial activities even after incubation at $121^{\circ}C$ for 15 min. These bacteriocin-producing bacteria and/or bacteriocins could be used in feed manufacturing as probiotics as an alternative to antibiotics in the livestock industry.

• 농약과학회지
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• 제10권3호
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• pp.230-236
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• 2006

선학초 (전초) 메탄올 조추출물이 오이 세균성모무늬병균인 Pseudomonas syringae pv. lacrymans, 토마토 풋마름병균인 Ralstonia solanacearum 및 담배세균성들불병균인 Pseudomonas syringae pv. tabaci에 대해서 항균활성을 나타내었다. 활성성분을 silica gel column 및 HPLC로 순수분리하여 LC-Mass 분석 결과 분자량 682.7을 갖는 물질로 추정 할 수 있었으며, 선학초에서 분리된 물질중 분자량 687.2를 나타내는 Agrimol A와 B를 구별하기 위하여 $^1H-NMR$, $^{13}C-NMR$ 스팩트럼 분석 결과 항균활성성분이 Agrimol B임을 확증할 수 있었다.

• Weed & Turfgrass Science
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• 제6권2호
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• pp.157-164
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• 2017

본 연구는 미생물을 이용하여 친환경적인 잔디관리를 위해 계분이나 돈분의 퇴비화 과정에서 얻어진 가축분 퇴비로부터 단백질 및 탄수화물 분해능과 잔디 갈색퍼짐병(large patch), 갈색마름병(brown patch), 그리고 동전마름병(dollar spot) 병원균에 항균활성을 보이는 미생물을 분리하기 위하여 실시하였다. 분리된 미생물은 총 68균주였고, 이들을 대상으로 단백질 분해활성, 탄수화물 분해활성 및 잔디 주요병원균에 대한 항균활성을 조사하여 활성이 높은 미생물 34균주를 선발하였다. 이 중에서 단백질과 탄수화물 분해 및 항균활성을 나타내는 균주인 ASC-14, ASC-18 및 ASC-35를 선발하였다. 이들 선발 균주를 대상으로 16s rRNA 유전자 분석 결과 ASC-14와 ASC-18은 B. amyloliquefaciens로 확인되었고, 반면에 ASC-35는 B. subtilis 세균으로 최종 동정되었다.

• The Plant Pathology Journal
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• 제29권3호
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• pp.294-304
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• 2013

To improve the integrated pest management (IPM) of hot pepper, field study was conducted in Hwasung from 2010 to 2012 and an IPM system was developed to help growers decide when to apply pesticides to control anthracnose, tobacco budworm, Phytophthora blight, bacterial wilt, and bacterial leaf spot. The three field treatments consisted of IPM sprays following the forecast model advisory, a periodic spray at 7-to-10-day intervals, and no spray (control). The number of annual pesticide applications for the IPM treatment ranged from six to eight, whereas the plots subjected to the periodic treatment received pesticide 11 or 12 times annually for three years. Compared to the former strategy, our improved IPM strategy features more intense pest management, with frequent spraying for anthracnose and mixed spraying for tobacco budworm or Phytophthora blight. The incidences for no pesticide control in 2010, 2011, and 2012 were 91, 97.6, and 41.4%, respectively. Conversely, the incidences for the IPM treatment for those years were 7.6, 62.6, and 2%, and the yields from IPM-treated plots were 48.6 kg, 12.1 kg, and 48.8 kg. The incidence and yield in the IPM-treated plots were almost the same as those of the periodic treatment except in 2011, in which no unnecessary sprays were given, meaning that the IPM control was quite successful. From reviewing eight years of field work, sophisticated forecasts that optimize pesticide spray timing reveal that reliance on pesticides can be reduced without compromising yield. Eco-friendly strategies can be implemented in the pest management of hot pepper.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1605-1613
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• 2010

Twenty-nine P. polymyxa strains isolated from rhizospheres of various crops were clustered into five genotypic groups on the basis of BOX-PCR analysis. The characteristics of several plant growth-promoting factors among the isolates revealed the distinct attributes in each allocated group. Under gnotobiotic conditions, inoculation of pepper roots with P. polymyxa isolates significantly increased the biomass in 17 of total 29 treated plants with untreated plants. Experiments on induced systemic resistance (ISR) against bacterial spot pathogen Xanthomonas axonopodis pv. vesicatoria in pepper by P. polymyxa strains were conducted and only one isolate (KNUC265) was selected. Further studies into ISR mediation by the KNUC265 strain against the soft-rot pathogen Erwinia carotovora subsp. carotovora in tobacco demonstrated that the tobacco seedlings exposed to either bacterial volatiles or diffusible metabolites exhibited a reduction in disease severity. In conclusion, ISR and plant growth promotion triggered by P. polymyxa isolates were systemically investigated on pepper for the first time. The P. polymyxa KNUC265 strain, which elicited both ISR and plant growth promotion, could be potentially used in improving the yield of pepper and possibly of other crops.