Pseudomonas syringae에 의한 사과나무 가지마름병의 발생

서상태,원선영,박덕환,김영숙,허장현,임춘근 한국식물병리학회 1999 식물병연구 Vol.5 No.1

참나무시들음병 나무주사 방제법

서상태 한국수목보호연구회 2013 수목보호 Vol.18 No.-

포도 잿빛곰팡이병의 생물적 방제를 위한 길항세균 선발

서상태,정승룡,박종한,한경숙 한국식물병리학회 2006 식물병연구 Vol.12 No.3

Botrytis cinerea Pers. was found to be highly virulent to the grapevine plant, especially in greenhouse condition. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. Of the 83 isolates of Pseudomonas spp., a bacterial strain P84, isolated from tomato rhizosphere, was shown to suppress a wide range of phytopathogenic fungi in vitro. The isolate was identified as Pseudomonas putida on the basis of its bacteriological and genetic characteristics. The P. putida P84 strain carry the phlD gene for 2,4- diacetylphloroglucinol biosynthesis and may produce the antibiotics as an antagonistic mechanism involved in biocontrol. The antagonistic activity of the bacterium has a promising implication for its use as a biocontrol agent to control grapevine gray mold.

Acidovorax avenae subsp. citrulli에 의한 멜론 과실썩음병

서상태,정승룡,박종한,이중섭,한경숙 한국식물병리학회 2006 식물병연구 Vol.12 No.3

In September and October 2005, melons (Cucumis melo L.) from the commercial greenhouses in Naju and Gwangju exhibited severe foliar necrosis and fruit rot. Leaf symptoms initially appeared as V-shaped, necrotic lesions and extending to the midrib. Symptoms on the fruit were occurred randomly as necrotic and sunken spots. Two isolates from diseased leaves and fruits were identified as Acidovorax avenae subsp. citrulli on the basis of bacteriological and genetic characteristics. Pathogenicity of the isolates was confirmed by inoculating on 3-week-old melon and cucumber seedlings. This is the first report of bacterial fruit blotch of melon in Korea.

우리나라에 분포하는 고추와 토마토 풋마름병균(Ralstonia solanacearum) 계통들의 유전적 다양성

서상태,이승돈,정승룡,박종한,한경숙 한국식물병리학회 2007 식물병연구 Vol.13 No.1

A total of 35 strains of Ralstonia solanacearum isolated from wilted pepper and tomato plants in Korea were analyzed for their genetic diversity by bacteriological, pathological and molecular biological approaches. All the strains were identified as R. solanacearum biovar 4 on the basis of physiological and biochemical tests, and species-specific PCR primers. Pathogenicity of the strains was confirmed by inoculating on 4-week-old pepper and tomato seedlings. Using cluster analysis based on repetitive sequence-based polymerase chain reaction (rep-PCR) genomic fingerprints, R. solanacearum strains isolated from pepper and tomato in Korea divided into 6 groups showing a high degree of genetic diversity at 55% similarity level. The genetic diversity of strains was not significantly correlated with their geographic origins and host plants.

마늘오일을 이용한 오이와 토마토 흰가루병 방제

서상태,장한익,이중섭,한경숙,박종한 한국식물병리학회 2006 식물병연구 Vol.12 No.1

The effectiveness of four plant oils (garlic, ginger, cinnamon and lemongrass) against a range of plant pathogenic organisms was tested in vitro. Of the four oils, two oils (garlic and cinnamon) showed relatively good antimicrobial activities. Activity of garlic oil was shown against the plant pathogenic bacteria Agrobacterium tumefaciens, Erwinia carotovora, Ralstonia solanacearum, Xanthomonas campestris, and the fungi Phytophthora infestans, Fusarium oxysporum, Collectotricum sp., whereas Acidovorax avenae and Pythium sp. showed the resistance towards garlic oil. Results from the planta bioassays under greenhouse conditions indicated that garlic oil significantly reduced the cucumber powdery mildew (Sphaerotheca fusca) and tomato powdery mildew (Erysiphe cichoracearum) showing control value 70.0-74.6% and 71.2%, respectively.

국내 소나무재선충에서 분리한 세균의 특성

서상태,문일성 한국식물병리학회 2012 식물병연구 Vol.18 No.4

A survey of bacterial species associated with Korean isolates of pine wood nematode (PWN) was performed. A total of 110 bacterial isolates were obtained from the PWN isolates that were previously isolated from Pinus densiflora and P. koraiensis. Among the bacterial isolates, Cedecea neteri was most frequent (64 isolates)followed by Ewingella americana (21 isolates), Pseudomonas sp. (15 isolates), Flavobacterium sp. (8 isolates)and Rahnella aquatilis (2 isolates). Both E. americana and Pseudomonas sp. which are assumed to be closely associated with PWN were examined for their phytotoxicity to P. thunbergii seedlings. Ethyl acetate extracts of Psuedomonas sp. (Ba2 strain) cultures were found to induce wilting and mortality in the tested seedlings. The three bacterial species, Pseudomonas sp. (Ba2 strain), E. ameircana (Ba4 strain) and C. neteri (Ba10strain) were examined in vitro for their sensitivity to 21 kinds of antibiotics. All of the strains were highly susceptible to carbenicillin, doxcycline and tetracycline.

참나무류에 시들음병을 일으키는 Raffaelea quercus-mongolicae와 R. quercivora의 유전적 특성

서상태,김경희,이상현,권용남,신창훈,김혜정,이상용 한국식물병리학회 2010 식물병연구 Vol.16 No.3

최근 신갈나무를 중심으로한 참나무과 나무에 시들음병 피해가 증가하고 있다. 한국과 일본에서 분리한 38개의 시들음병 균주(Raffaelea quercus-mongolicae, R.quercivora)에 대해 β-tubulin 유전자 염기서열 분석과 RAPD 분석을 이용해 유전적 특성을 조사하였다. β-tubulin 유전자 염기서열을 이용한 cluster 분석결과 시들음병 균주들은 4개의 그룹으로 나뉘었으며, cluster 2와 4에는 1균주를 제외하고 모두 일본균주가 속해 있었다. RAPD 분석결과 시들음병 균주들은 3개의 그룹으로 나뉘었으며, 한국균주와 일본균주는 쉽게 구별되었다. β-tubulin 유전자 염기서열 분석과 RAPD 분석결과 한국균주와 일본균주는 상당히 다른 유전적 특성을 가지고 있었다. Recently, the oak wilt diseases especially on Quercus mongolica, have been increasing in various districts of Korea. A collection of 38 strains of the oak wilt pathogen Raffaelea qeurcus-mongolicae and R. quecivora isolated from Quercus spp. in Korea and Japan was characterized by β-tubulin gene sequence and randomly amplified polymorphic DNA (RAPD) analysis. In cluster analysis based on β-tubulin gene sequence the strains were divided into 4 clusters, of which clusters 2 and 4 were composed of Japanese strains except for one Korean strain. RAPD analysis showed that they were also effectively differentiated by a strong RAPD fragments. On the basis of the two genetic analysis, significant differences were detected between Korean strains and Japanese strains.

벚나무 빗자루병균(Taphrina wiesneri)에 대한 살균제의 방제효과

서상태,김경희,이상현,김영말,신상철,신창훈,박종한 한국식물병리학회 2009 식물병연구 Vol.15 No.1

In April 2008, cherry (Prunus yedoensis Matsumura) in Jeju exhibited severe disease of branches forming numerous twigs. Five isolates from diseased leaves were identified as Taphrina wiesneri on the basis of biological and genetic characteristics. Twenty one commercial fungicides were tested for control of the disease in vitro. Of the 21 fungicides, triazole compounds (difenoconazole, propiconazole and tebuconazole) showed relatively good antimicrobial activities. Results from the planta bioassays indicated that triazole compounds reduced the witches' broom disease showing control value 25.7~52.8% compared with the nontreated controls. In April 2008, cherry (Prunus yedoensis Matsumura) in Jeju exhibited severe disease of branches forming numerous twigs. Five isolates from diseased leaves were identified as Taphrina wiesneri on the basis of biological and genetic characteristics. Twenty one commercial fungicides were tested for control of the disease in vitro. Of the 21 fungicides, triazole compounds (difenoconazole, propiconazole and tebuconazole) showed relatively good antimicrobial activities. Results from the planta bioassays indicated that triazole compounds reduced the witches' broom disease showing control value 25.7~52.8% compared with the nontreated controls.

Pseudomonas putida P84 균주를 이용한 토마토 풋마름병의 억제

서상태,오은성,신상철,김경희,박종한,이상현 한국식물병리학회 2008 식물병연구 Vol.14 No.1

Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tomato in Korea and no effective control measures are available yet. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. A rhizobacterial population of 150 Pseudomonas strains, isolated from the rhizosphere soil of various plants grown at different sites, was screened for 2,4-diacetylphloroglucinol producing gene (phlD) by PCR. Two strains (P83 and P84) among them were found to be phlD positive. When the isolates were analysed by 16S rDNA (Sensu Stricto), all isolates yielded amplified products of 1,018 bp. Of the 150 isolates of Pseudomonas spp., a bacterial strain P. putida P84 isolated from tomato rhizosphere showed to suppress a wide range of phytopathogenic bacteria in vitro. The best source of carbon for P84 strain were glucose, arabinose, inositol and melibiose. In greenhouse experiments, P84 strain suppressed the development of bacterial wilt in tomato with a control value of 60%. Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tomato in Korea and no effective control measures are available yet. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. A rhizobacterial population of 150 Pseudomonas strains, isolated from the rhizosphere soil of various plants grown at different sites, was screened for 2,4-diacetylphloroglucinol producing gene (phlD) by PCR. Two strains (P83 and P84) among them were found to be phlD positive. When the isolates were analysed by 16S rDNA (Sensu Stricto), all isolates yielded amplified products of 1,018 bp. Of the 150 isolates of Pseudomonas spp., a bacterial strain P. putida P84 isolated from tomato rhizosphere showed to suppress a wide range of phytopathogenic bacteria in vitro. The best source of carbon for P84 strain were glucose, arabinose, inositol and melibiose. In greenhouse experiments, P84 strain suppressed the development of bacterial wilt in tomato with a control value of 60%.