• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.487-490
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• 2006

Because of consumer rejection of chemical pesticides and the appearance of microorganisms that are resistant to fungicides, we tried to discover biopesticides. Of 13 microorganisms isolated from Shrimp-jeotkal, a Bacillus sp. showed strong activity against tomato late blight caused by Phytophthora infestans. Its activity was tested both in vivo and in vitro. The identification of the strain was carried out based on 16S rDNA analysis and the morphology by scanning electron microscopy.

• 한국자원식물학회지
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• 제21권4호
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• pp.260-264
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• 2008

고추 형질전환체 $T_1$ 및 $T_2$세대의 유묘에 역병균을 접종한 결과 유주포자 $10^3$개/mL에서 접종 5일후 역병 발병율은 $T_1-1$계통 4.0%, $T_1-2$ 10.0%이었으며, 접종 12일후는 $T_1-1$ 계통 52.0%, $T_1-2$ 계통 64.0%로 대비종인 '금탑'과 '수비초' 100%에 비해 발병율이 떨어져 유주포자 $10^3$개/mL에서는 형질전환체의 저항성 계통선발이 가능하였다. 획득된 역병 저항성 형질전환체를 영양고추시험장의 역병 상습포장에서 재배한 결과 생육, 개화소요일수, 과특성 등은 계통간에 다소 차이가 있었으나, 과실모양은 수비초와 매우 유사하였다. 포장에서의 역병의 발생은 계통간에 차이가 많았으며, $T_2-1-6$ 계통과 $T_2-4-9$ 계통은 시판종인 금탑에 비해 약 30%정도 적었다. 포장에서 선발된 형질전환체는 세대의 진전을 통한 저항성의 고정이 필요한 것으로 판단된다. 이상의 결과로 본 연구에서 확립된 형질전환 시스템으로 고추의 역병저항성 형질전환체의 육성이 가능할 것으로 생각된다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.128.1-128
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• 2003

A leaf blight disease was found on Fatsia japonica plants growing in the first author's apartment garden in May, 2003. Major symptoms were leaf blight and petiole rot. A species of Phytophthora was isolated from the lesions. The isolate readily produced sporangia and sex organs on V8 juice agar plates. Sporangia were papillate, ovoid to subspherical and caducous with a pedicel. Sporangia were 33.6-38.4 ${\times}$ 33.6$\mu\textrm{m}$ with 1/b ratio approximately 1.14, papillae 4-5$\mu\textrm{m}$ high, pedicels also 4-5$\mu\textrm{m}$ long. Oogonia were spherical, 28.8$\mu\textrm{m}$ in diameter. Antheridia were globose, 14.4$\mu\textrm{m}$ in diameter and mating with oogonia paragynously. Mycelia grew best at 30$^{\circ}C$ and did not grow at 35$^{\circ}C$ or above, and at 5$^{\circ}C$. The morphological characteristics conformed to P. cactorum (Leb. And Cohn) Schroeter.

• The Plant Pathology Journal
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• 제15권4호
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• pp.217-222
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• 1999

Treatment with antagonistic rhizobactera Burkholderia cepacia strain N9523 or an inducer of resistance DL-$\beta$-amino-n-butyric acid (BABA) effectively inhibited Phytophthora capsici infection on pepper plants in artificially infested pots. Treatment with BABA alone at $1,000\mu\textrm{g}$/ml or together with B. cepacia in combination induced a strong protection from the Phytophthora disease in the greenhouse. In artificially infested field, protection of pepper plants against the Phytophthora epidemic by BABA treatment was maintained at a considerable level. In contrast, soil drench with the antagonist B. cepacia alone, or in combination with BABA did not suppress the Phytophthora epidemic in the field. Mortality of pepper plants caused by P. capsici infection was significantly reduced by treatment with the antagonist Pseudomonas aeruginosa strain 950923-29 and BABA (12-29% plants diseased) relative to the untreated control (41-91% plants diseased) in the naturally infested field. Treatment with the antagonist Ps. aeruginosa strain 950923-29 and BABA also resulted in high levels of protection against Phytophthora blight in pepper plants. In the plastic filmhouse test, the average percentage of plants diseased was significantly low relative to the naturally infested field. Treatment with the antagonist Ps. aeruginosa strain 950923-29 and BABA in combination was most effective in suppressing the Phytophthora disease in field and plastic filmhouse.

• Applied Biological Chemistry
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• 제50권3호
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• pp.192-197
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• 2007

고추역병균(Phytophthora capsici)에 대한 N-phenylbenzenesulfonamide 및 N-phenyl-2-thienylsulfonamide 유도체(1-37)들의 살균활성에 관한 3차원적인 정량적 구조와 활성과의 관계(3DQSARs)들을 비교 분자장 분석(CoMFA)과 비교분자 유사성 지수분석(CoMSIA) 방법으로 각각 검토하였다. CoMFA(2) 모델($r^2_{cv.}(q^2)$ = 0.692 및 $r^2_{ncv.}$= 0.965)이 CoMSIA(2) 모델($r^2_{cv.}(q^2)$ =0.796 및 $r^2_{ncv.}$= 0.958)보다 상관성과 예측성이 양호하였다. 최적의 CoMFA(2) 모델에 따른 살균활성은 분자의 입체장과 정전기장에 의존적이었다. 또한, CoMFA(2) 모델의 등고도 분석 결과로부터 살균활성의 63%가 입체적으로 큰 S-phenyl 고리의 meta-치환기($R_1$) 그리고 나머지 살균활성의 32.9%가 양하전을 띄는 N-phenyl 고리의 $R_4$-치환기와 S-phenyl 고리의 para-치환기($R_1$)에 기인하는것으로 예측되었으며 이 같은 사실에 기초하여 일련의 고활성 화합물, $R_1$ = 3-decyl 치환체 ($pred.pI_50$ = 5.88) 등이 예측되었다.

• The Plant Pathology Journal
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• 제20권3호
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• pp.177-183
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• 2004

Phenylacetic acid (PAA) was evaluated for in vitro anti-oomycete activity and in vivo control efficacy against Phytophthora capsici. Microscopic observation revealed that the high level of anti-oomycete activity of PAA (10 $\mu\textrm{g}$/ml) against P. capsici is mainly due to the lytic effect on zoospores. Zoospore lysis began in the presence of 5 u$\mu\textrm{g}$/ml of PAA and most of the zoospores were collapsed at 10 $\mu\textrm{g}$/ml. PAA showed inhibitory activity against the zoospore germination and hyphal growth of P. capsici at the concentration of 50 $\mu\textrm{g}$/ml. In the glasshouse, the protective effect of PAA against Phytophthora blight was high on pepper plants when treated just before inoculation with P. capsici. In the artificially infested field, protection of pepper plants against the Phyto-phthora epidemic was achieved at a considerable level by PAA treatment.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.86-86
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• 2003

Phytophthora capsici is a pathogen on several economically important crops including pepper. In pepper growing areas in Korea, Phytophthora blight caused by p. capsici has been considered as the most serious problem in pepper production. The Oomycete attacks the roots, stems, leaves and fruits of the plant. To understand the molecular mechanisms involved in the disease development, the genes expressed doting pepper p. capsici interaction were explored by analyzing expressed sequence tags (ESTs). A complementary DNA (cDNA) library was constructed from total RNA extracted from pepper leaves challenged with p. capsici for 3 days resulting in early stage of symptom development. The comprehensive analysis on the single pass sequencing of over 4000 randomly selected cDNA clones with contig assembly, unique gene extraction, sequence comparison, and functional categorizing will be presented with an emphasis on the genes involved in plant defense and pathogenicity during disease development of the pepper Phytophthora blight.

• The Plant Pathology Journal
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• 제22권4호
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• pp.309-313
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• 2006

Phytophthora blight(PB), caused by Phytophthora drechsleri f. sp. cajani is the third potentially important disease of pigeonpea in the Deccan Plateau(DP) of India after wilt and sterility mosaic. In the rainy-season of 2005, an outbreak of PB was seen throughout DP. To quantify the incidence and spread of the disease, a systematic survey was conducted in the major pigeonpea growing regions of DP during the crop season 2005. Attempts were made to determine the effect of cropping systems on the PB development and identify resistant cultivars, if any, grown by farmers and on research farms. Widespread incidence of PB was recorded on improved, and or local cultivars grown in different intercropping systems. Majority of improved cultivars grown at research farms were found susceptible to PB(>10% disease incidence). Pigeonpea intercropped with groundnut, black gram and coriander had less disease incidence(${\leq}10%$). Three wilt and SM resistant pigeonpea cultivars KPL 96053, ICPL 99044, and ICPL 93179 were found resistant(<10%) to PB as well. However, their resistance to PB needs confirmation under optimum disease development environments.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.77-81
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• 1996

During the screening for the antifungal compounds against Phytophthora capsici causing phytophthora blight of red pepper, we isolated a strong active compound, bafilomycin $C_1$, produced by strain 3D3. The producing organism was identified as Streptomyces sp. based on taxonomic studies. The antifungal compound was purified from culture broth by HP-20 column chromatography, ethylacetate extraction, silica gel column chromatography and HPLC, and was identified as bafilomycin $C_1$ by color reaction, UV and $^{1}H$-NMR spectral data analysis. Bafilomycin $C_1$ showed strong antifungal activity against various phytopathogenic fungi.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1994년도 Proceedings of International Symposium on BIOLOGICAL CONTROL OF PLANT DISEASES Korean Society of Plant Pathology
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• pp.50-61
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• 1994

Biological control of important fungal diseases such as Phytophthora blight of red pepper, gary mold rot of vegetables, and powdery mildew of many crops was attempted using an antagonistic bacterium, Bacillus sp. AC-1 in greenhouses and fields. The antagonistic bacterium isolated from the rhizosphere soils of healthy red pepper plant was very effective in the inhibition of mycelial growth of plant pathogenic fungi in vitro including Phytophthora capsici, Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea, Valsa mali, Fusarium oxysporum, Pythium ultimum, Alternari mali, Helminthosporium oryzae, and Colletotrichum gloeosporioides. Culture filtrate of antagonistic Bacillus sp. AC-1 applied to pot soils infested with Phytophthora capsici suppressed the disease occurrence better than metalaxyl application did until 37 days after treatment in greenhouse tests. Treatments of the bacterial suspension on red pepper plants also reduced the incidence of Phytophthora blight in greenhouse tests. In farmers' commercial production fields, however, the controlling efficacy of the antagonistic bacteria was variable depending on field locations. Gray mold rot of chinese chives and lettuce caused by Botrytis cinerea was also controlled effectively in field tests by the application of Bacillus sp. AC-1 with control values of 79.7% and 72.8%, respectively. Spraying of the bacterial suspension inhibited development of powdery mildew of many crops such as cucumber, tobacco, melon, and rose effectively in greenhouse and field tests. The control efficacy of the bacterial suspension was almost same as that of Fenarimol used as a chemical standard. Further experiments for developing a commercial product from the antagonistic bacteria and for elucidating antagonistic mechanism against plant pathogenic fungi are in progress.