Clavibacter michiganensis subsp. michiganensis에 의한 고추 궤양병

이승돈,윤창만,이영기,최용철,조용섭 한국식물병리학회 1999 식물병연구 Vol.5 No.2

Xanthomonas campestris pv. campestris에 의한 브로콜리의 검은썩음병

이승돈,이정희,허성기,김선이,김용기,이용훈,나동수 한국식물병리학회 2006 식물병연구 Vol.12 No.2

A new bacterial disease of broccoli (Brassica oleracea var. italica) was observed on field-grown plants in Pyungchang during 2003 and 2004. Seedling infections first appeared as a blackening along the margins of the cotyledon. Cotyledon shriveled and dropped off. Infected seedlings were stunted and yellowed and eventually died. The disease was easily recognized by the presence of yellow, V-shaped, or U-shaped areas extending inward from margin of the leaf. As the disease progressed, the yellow lesions turned brown and the tissues died. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Two bacterial strains were purified and used for further tests. Pathogenicity of strains was confirmed on 3-week-old crucifer (cabbage, Chinese cabbage, kale, radish and broccoli) plants cut by scissors with bacterial suspensions containing 108 cfu/ml of phosphate buffered saline. The Biolog and fatty acid analyses and 16S rDNA sequencing of two strains (SL4797 and SL4800) from broccoli black rot showed that they could be identified as X. campestris pv. campestris because of their high similarity to the tester strain (X. campestris pv. campestris NCPPB528) with a match probability of 100%. This is the first report of black rot of broccoli in Korea.

Xanthomonas axonopodis pv. phaseoli와 X. axonopodis pv. phaseolivar. fuscans에 의한 팥의 세균성잎마름병

이승돈,문중경,허성기,이정희,나동수 한국식물병리학회 2006 식물병연구 Vol.12 No.2

A bacterial disease of small red bean (Phaseolus angularis) was observed on field-grown plants in Suwon in year 2003. Leaf symptoms initially appeared as water-soaked spots that gradually enlarged, became flaccid and necrotic and were often bordered by a small zone of lemon yellow tissue. In the case of severe infection, dead leaves were defoliated. Pod symptoms consisted of the lesions that were generally circular, slightly sunken and dark reddish brown. Isolation made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Three bacterial strains were purified and used for further tests. Pathogenicity of strains was confirmed on 3-weekold small red bean plants sprayed with bacterial suspensions containing 108 cfu/ml of phosphate buffered saline. The representative Xanthomonas strains isolated from small red bean were compared with X. axonopodis pv. phaseoli and X. axonopodis pv. phaseoli var. fuscans type strains for fatty acid profiles, biochemical tests and metabolic fingerprints using Biolog GN2 microplate, showing that all outcomes were indistinguishable between our isolates and reference strains. Two of three strains produced a melanin-like brown pigment extracellularly on King's medium B agar. These results suggest that this new small red bean disease observed in Suwon is bacterial fuscous blight caused by X. axonopodis pv. phaseoli and X. axonopodis pv. phaseoli var. fuscans.

방제포커스(1) 수박병해 - 시설내 일정한 온도유지 및 습도 낮추는 환경조절 필수

이승돈,Lee, Seung-Don 한국작물보호협회 2012 자연과 농업 Vol.275 No.-

Xanthomonas hortorum pv. hederae에 의한 헤데라 세균성점무늬병

이승돈,서상태,허성기,이정희,한경숙,김용기,나동수 한국식물병리학회 2007 식물병연구 Vol.13 No.1

English ivy (Hedera helix) in Araliaceae family is an evergreen climbing vine. A severe bacterial disease of English ivy was observed and investigated in January 2005. Initial symptoms on the leaves appeared as small water-soaked lesions on the lower surface. As the spots enlarged, the center became brown to brownish black and greenish-brown water-soaked, irregular margins surrounded the center. The spots developed into large irregular blotches, sometimes 5~10 mm in diameter, then coalesced. Finally, the water-soaked margins raised, dried out, became corky and broke in the center. A bacterial organism, isolated from the advancing margins of the lesions, was tested for its pathogenicity according to the Koch's postulates and biochemical and physiological tests identified the isolated bacterium as a Xanthomonas. The representative Xanthomonas strains (SL4821 and SL4822) isolated from English ivy were compared with a reference strain X. hortorum pv. hederae for fatty acid profiles, metabolic fingerprints and 16s rDNA sequences, showing that all outcomes were indistinguishable between the representative and reference strains. This is the first report of bacterial leaf spot of English ivy in Korea.

Diversity of PthA Gene of Xanthomonas Strains Causing Citrus Bacterial Canker and its Relationship with Virulence

이승돈,이정희,이동희,이용훈 한국식물병리학회 2008 Plant Pathology Journal Vol.24 No.3

Several pathotypes have been recognized in citrus bacterial canker, which causing serious damage in citrus cultivation area. To control the disease, it is important to understand the pathological diversity and reason of difference in virulence of the causal pathogen. We analyzed 124 strains of Xanthomonas causing citrus bacterial canker by southern hybridization with an internal 3.4-kb BamHI fragment from pthA gene. Assuming each band represented an intact gene, each strain of Xanthomonas was estimated to have approximately 1 to 4 copies of pthA gene. X. a. pv. citri A type had more than 3 copies of pthA gene, and the number of pthA gene in X. a. pv. citri A*, Aw, and X. a. pv. aurantifolii B, C were different from 1 to 3 according to the strains. When the pthA gene profile was classified into 13 groups according to the number and size of hybridization bands, most of the A types belong to the 3A group, and 4A and 4B type was dominant when they had 4 bands. However, there was no general pattern of difference between the virulence and pthA gene group in this test.

Xanthomonas campestris pv. vitians에 의한 상추 세균성점무늬병

이승돈,허성기,이정희,김용기,나동수 한국식물병리학회 2007 식물병연구 Vol.13 No.1

During 1997 and 1998, a new disease of lettuce (Lactuca sativa) was observed on greenhouse-grown plants in Kwangju and Kwangmyung. Lesions on leaves were irregular, small, pale green to black, water-soaked, and 2 to 5 mm in diameter. Coalescing lesions sometimes caused defoliation of older leaves. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow pigmented bacterium typical of a xanthomonad. Two bacterial strains (SL0246 and SL1352) were purified and used for further tests. Pathogenicity of strains was confirmed on 5-week-old lettuce plants injected with bacterial suspensions containing 108 cfu/ml of phosphate buffered saline. The representative Xanthomonas strains isolated from lettuce were compared with a reference strain X. campestris pv. vitians for fatty acid profiles and metabolic fingerprints using GN2 microplate, showing that all outcomes were indistinguishable between the representative and reference strains. This is the first report of bacterial leaf spot and dry rot of lettuce in Korea.

식물병원세균에 의한 유도 저항성

이승돈,허성기,나동수,노은정 한국육종학회 2008 한국육종학회 학술발표회 발표요지 Vol.40 No.1

Xanthomonas campestris pv. sesami에 의한 참깨의 세균성잎마름병

이승돈,허성기,이정희,김용기,나동수 한국식물병리학회 2005 식물병연구 Vol.11 No.2

A new bacterial disease of sesam (Sesamum indicum) was observed on field-grown plants in Suwon, Hongchun and Yeonchun in 2000. Leaf symptoms initially appeared as water-soaked spots that gradually enlarged, became necrotic, and were often bordered by a small zone of lemon yellow tissue. In the case of severe infection, dead leaves were defoliated. Isolations made from diseased leaves on yeast extract dextrose calcium carbonate agar yielded nearly pure cultures of a yellow-pigmented bacterium typical of a xanthomonad. Two bacterial strains were purified and used for further tests. Pathogenicity of strains was confirmed on 3-week-old sesame plants sprayed with bacterial suspensions containing 108 cfu/ml of phosphate buffered saline. The Biolog and fatty acid analyses of the two strains(SL3451 and SL3476) from sesame leaf blight showed that they could be identified as X. campestris pv. sesami because of their high similarity to the tester strain(X. campestris pv. sesami LMG865) with a match probability of 100%. The bacterium grew well between 18 and 36oC, but optimum temperature was 27oC on LB broth. This is the first report of bacterial blight of sesame in Korea. Symptoms of bacterial blight of sesame are difficult to differentiated with those of bacterial leaf spot caused by Pseudomonas syringae pv. sesami. 2000년 수원, 홍천, 연천 지역의 참깨 포장에서 새로운 병해가 발견되었다. 처음에는 잎에 수침상의 작은 점무늬를 형성하다가 점점 커져 괴사가 일어나고 주위로 황화되었다. 심하게 감염된 경우는 병든 잎은 떨어졌다. YDC배지에서 병원세균을 순수 분리 하였을 때 Xanthomonas 속 세균의 전형적인 특징인 노란색 색소를 띤 세균이 형성되었다. 분리된 세균을 108 cfu/ml로 현탁한 후 3주 동안 자란 참깨 잎에 분무 접종하였을 때 처음과 같은 증상이 재현되었다. 분리된 세균은 대조균주 X. campestris pv. sesami LMG865와 지방산 조성 및 다양한 탄소원 이용정도를 이용하여 비교하였을 때 100%의 가능성으로 X.campestris pv. sesami로 동정되었다. 분리된 병원균은 18~36oC에서 생장이 양호하였으며, 27oC에서 가장 우수 하였다. 이 보고는 국내에서 참깨의 세균성잎마름병 최초 보고이며, P. syringae pv. sesami에 의한 세균성점무늬병과 외부적인 병징으로 구별하기가 매우 어렵다.

퍼지를 이용한 힘 제어에 관한 연구

이승돈(Seung Don Lee),김경대(Kyoung Dae Kim),박종현(Jong Hyeon Park),한창수(Chang Su Han),장경영(Kyoung Young Chang),감도영(Do Young Kam) 제어로봇시스템학회 1995 제어로봇시스템학회 국내학술대회 논문집 Vol.1 No.2