• 한국식물병리학회지
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• 제14권4호
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• pp.345-349
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• 1998

Fifty isolates of myxobacteria were isolated from soils from several areas in Korea during 1996-1997 and bioactivity against plant pathogenic fungi of these isolates was examined. A myxobacterial isolate KR025 showed good antifungal activities against Pyricularia oryzae, Cryphonectria parasitica, Colletotrichum lagenarium, and C. gloeosporioides but did not against Rhizoctonia solani, Fusarium oxysporum and Pythium ultimum. The bacterium was identified as Myxococcus fulvus based on morphological and physiological characteristics. Antifungal substances were extracted from culture broth and bacterial cell of Myxococcus fulvus KR025 by ethyl acetate. Antifungal substance of Myxothiazole (100 ${\mu}{\textrm}{m}$/ml) produced by Myxococcus fulvus KR 025 controlled 97.0% rice blast, tomato late blight, wheat leaf rust, and barley powdery mildew and showed 45.0 and 82.6% disease control of rice sheath blight and cucumber gray model, respectively.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.204-208
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• 2002

A Streptomyces sp. isolated from a soil sample collected in Taejeon, Korea has previously been found to produce two new polyene antibiotics. The two new antibiotics were named "16-methyloxazolomycin (antibacterial)" and "tetrin C (antifungal)", and their chemical structures are presented elsewhere [10, 11]. In the current study, chemotaxonomy, numerical taxonomy, and ISP methods were all employed for the taxonomic study. The spore chains were spirales and the spore surface was smooth. The spore mass was a gray series and no melanin pigment was produced. On the basis of the morphological and physiological properties, the microorganism was identified to be Streptomyces erumpens, belonging to the gray series of category IV, as defined by Bergey′s Manual. Tetrin C at the concentration of 20 ${\mu}g$/ml demonstrated a potent in vivo (pot test) preventive effect against rice blast, rice sheath blight, cucumber gray mold, wheat powdery mildew, and barley leaf rust.

• The Plant Pathology Journal
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• 제26권3호
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• pp.280-285
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• 2010

In the course of a searching natural antifungal compounds from plant sources, we found that the methanol extract ($3,000\;{\mu}g/ml$) of Malus domestica fruits had potential of control against rice blast (Magnaporthe grisea) and tomato late blight (Phytophthora infestans). Under bioassay-guided purification, we isolated phloretin, a phenolic compound, with in vivo antifungal activity against M. grisea. By 1-day protective application of phloretin ($500\;{\mu}g/ml$), the compound strongly inhibited the disease development of M. grisea and P. infestans on rice and tomato seedlings, respectively. And red pepper anthracnose caused by Colletotrichum coccodes also was moderately suppressed. However, rice sheath blight (Rhizoctonia solani AG1), and barley powdery mildew (Blumeria graminis f. sp. hordei) were hardly controlled. In addition, the compound showed in vitro antifungal activity against some plant pathogenic fungi including Phytophthora capsici, Alternaria panax, Sclerotinia sclerotiorum, R. solani AG4, and M. grisea. This is the first report on the antifungal activity of phloretin against plant pathogenic fungi.

• 한국약용작물학회지
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• 제5권3호
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• pp.206-210
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• 1997

6월 하순부터 1개월 간격으로 작약의 잎과 줄기에 인위적 고사를 유도하여 지상부 고사가 뿌리의 발달, 수량, 상품성에 미치는 영향을 구명코자 시험한 결과는 다음과 같다. 1. 작약의 잎과 줄기를 고사시키는 주 병원균은 점무늬병균, 녹병균, 흰가루병균, 검은무늬병균, 탄저병균, 갈색점무늬병원균이었다. 2. 점무늬병과 흰가루병은 4월 하순에서 5월 중순경에 발병되었고, 녹병은 6월 상 순부터 발생되어 시일이 경과할수록 발생율이 증가하였다. 3. 작약 지상부의 고사는 5월 하순부터 시작되어 8월 하순경에는 50% 이상의 고사율을 보였다. 4. 수량은 정상주에 비해 6월 하순 및 7월 하순 고사가 $31{\sim}35%$ 감수되었고, 8월 하순과 9월 하순 고사가 $7{\sim}12%$의 감수를 보였다. 5. 직경 10mm이상 상품성이 있는 뿌리수는 6월과 7월 고사가 8월이후 고사에 비해 적었고 주성분 Paeoniflorin 함량은 조기에 고사된 작약 뿌리 가 오히려 높았다.

• Mycobiology
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• 제41권4호
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• pp.234-242
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• 2013

A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activity against pathogenic fungi by dual culture method. The isolate CNU114001 was identified as Bacillus amyloliquefaciens by morphological observation and molecular data analysis, including 16SrDNA and gyraseA (gyrA) gene sequences. Antifungal substances of the isolate were extracted and purified by silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography. The heat and UV ray stable compound was identified as iturin, a lipopeptide (LP). The isolate CNU114001 showed broad spectrum activity against 12 phytopathogenic fungi by dual culture method. The semi purified compound significantly inhibits the mycelial growth of pathogenic fungi (Alternaria panax, Botrytis cinera, Colletotrichum orbiculare, Penicillium digitatum, Pyricularia grisea and Sclerotinia sclerotiorum) at 200 ppm concentration. Spore germ tube elongation of Botrytis cinerea was inhibited by culture filtrate of the isolate. Crude antifungal substance showed antagonistic activity against cucumber scleotiorum rot in laboratory, and showed antagonistic activity against tomato gray mold, cucumber, and pumpkin powdery mildew in greenhouse condition.

• 한국균학회지
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• 제21권2호
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• pp.120-126
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• 1993

Microsphaera속(屬) 흰가루병균(病菌) 중에서 아시아의 극동지방(極東地方)에서만 채집(採集)되는 M. akebiae, M. picrasmae, 그리고 M. schizandrae 등 3종(種)을 각각 으름, 소태나무 그리고 오미자에서 채집(採集)하여 이들이 갖는 무성세대(無性世代)의 형태적(形態的) 분류특성(分類特性)을 검경(檢鏡)하였다. 그 결과, 지금까지 잘못 알려진 형태적(形態的) 특성(特性)을 수정기재(修正記載)하였으며, 보고(報告)되지 않았던 몇 가지 분류특성(分類特性)을 추가기재(追加記載)하였다. 이들 3종(種)에서 관찰된 많은 분류특성(分類特性)들은 Microsphaera속(屬)에 공통적(共通的)으로 나타나는 것이었다. 즉, 부착기(附着器)는 파상(波狀) 내지 굴곡상(屈曲狀)으로서 쌍(雙) 또는 단독(單獨)으로 존재(存在)하였고, 분생자경(分生子梗)은 모세포(母細胞) 당(當) 1-2개(個)였고, 분생포자(分生胞子)를 단생(單生)하였으며, 기부격막(基部隔膜)은 균사(園絲)와의 분기점(分技點)에 있었다 . 분생포자(分生胞子)는 피브로신체(體)를 함유(含有)하지 않았으며, 발아관(發芽管)은 포자(胞子)의 끝에 위치(位置)하였다. 그러나 이들 3종(種)은 모두 분생자경(分生子梗)의 기부세포(基部細胞)가 굴곡상(屈曲狀)으로서 대부분의 Microsphaera속(屬) 흰가루병균(病菌)과 달랐으며, 각 종(種)은 분생자경(分生子梗)의 크기와 분생포자(分生胞子)의 크기 및 형태(形態) 등으로 서로 유별(有別)할 수 있었다. 따라서 이들 흰가루병균을 무성세대(無性世代)에서도 동정(同定)할 수 있게 되었다.

• The Plant Pathology Journal
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• 제22권1호
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• pp.94-96
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• 2006

In a search for plant extracts with potent in vivo antifungal activity against various plant pathogenic fungi, the methanol extract of the Curcuma longa rhizomes effectively controlled the development of rice blast catised by Magnaporthe grisea and tomato late blight caused by Phytophthora infestans. Three curcuminoids such as curcumin, demethoxycurcumin, and bisdemethoxycurcumin were purified from the methanol extract of C. longa rhizomes as antifungal principles. Among the three curcuminoids, demethoxycurcumin was the most active to both rice blast and tomato late blight, followed in order by curcumin and bisdemethoxycurcumin. However, they all exhibited no or little in vivo antifungal activity against other fungal pathogens causing rice sheath blight (Corticium sasaki), tomato gray mold (Botrytis cinerea), wheat leaf rust (Puccinia recondita), or barley powdery mildew (Blumeria graminis f. sp. hordel).

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.112-117
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• 2005

Abstract Griseofulvin has been used as an antifungal antibiotic for the treatment of mycotic diseases of humans and veterinary animals. The purpose of this work was to identify a griseofulvin-producing endophytic fungus from Abies holophylla and evaluate its in vivo antifungal activity against plant pathogenic fungi. Based on nuclear ribosomal ITS1-5.8SITS2 sequence analysis, the fungus was identified and labeled as Xylaria sp. F0010. Two antifungal substances were purified from liquid cultures of Xylaria sp. F0010, and their chemical identities were determined to be griseofulvin and dechlorogriseofulvin through mass and NMR spectral analyses. Compared to dechlorogriseofulvin, griseofulvin showed high in vivo and in vitro antifungal activity, and effectively controlled the development of rice blast (Magnaporthe grisea), rice sheath blight (Corticium sasaki), wheat leaf rust (Puccinia recondita), and barley powdery mildew (Blumeria graminis f. sp. hordei), at doses of 50 to 150 ${\mu}$g/ml, depending on the disease. This is the first report on the production of griseofulvin and dechlorogriseofulvin by Xylaria species.

• The Plant Pathology Journal
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• 제33권5호
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• pp.488-498
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• 2017

The aim of this study was to identify volatile and agardiffusible antifungal metabolites produced by Bacillus sp. G341 with strong antifungal activity against various phytopathogenic fungi. Strain G341 isolated from four-year-old roots of Korean ginseng with rot symptoms was identified as Bacillus velezensis based on 16S rDNA and gyrA sequences. Strain G341 inhibited mycelial growth of all phytopathogenic fungi tested. In vivo experiment results revealed that n-butanol extract of fermentation broth effectively controlled the development of rice sheath blight, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew, and red pepper anthracnose. Two antifungal compounds were isolated from strain G341 and identified as bacillomycin L and fengycin A by MS/MS analysis. Moreover, volatile compounds emitted from strain G341 were found to be able to inhibit mycelial growth of various phytopathogenic fungi. Based on volatile compound profiles of strain G341 obtained through headspace collection and analysis on GC-MS, dimethylsulfoxide, 1-butanol, and 3-hydroxy-2-butanone (acetoin) were identified. Taken together, these results suggest that B. valezensis G341 can be used as a biocontrol agent for various plant diseases caused by phytopathogenic fungi.

• 식물병연구
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• 제10권4호
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• pp.349-352
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• 2004

4품종(남도마늘, 고흥마늘, 단양마늘, 중국산 수입마늘)의 마늘추출액의 식물병원세균과 진균에 대한 항균효과를 조사하였다. 실내실험에서 마늘추출액은 그람양성세균, 그람음성세균, 진균 모두에 좋은 항균효과를 나타내었다. 본 연구에 사용된 4품종의 마늘추출액 중 남도마늘과 중국산 수입마늘이 보다 좋은 항균효과를 나타내었다. 그람양성세균인 Clavibacter michiganensis가 마늘추출액에 가장 민감하였으며, Burkholderia cepacia가 가장 저항성이 컸다. 마늘추출액을 이용한 오이 흰가루병에 대한 항균효과 포장실험에서는 59.7${\sim}$61.9%의 방제가를 보여주었다.