• 제목/요약/키워드: bacterial leaf spot

검색결과 55건 처리시간 0.026초

Screening of Some Indigenous and Exotic Mulberry Varieties against Major Foliar Fungal and Bacterial Diseases

  • Maji M.D.;Sau H.;Das B.K.;Urs S. Raje
    • International Journal of Industrial Entomology and Biomaterials
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    • 제12권1호
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    • pp.35-39
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    • 2006
  • Fifty-six indigenous and twenty nine exotic mulberry varieties were screened against powdery mildew, Myrothecium leaf spot, Pseudocercospora leaf spot, sooty mold and bacterial leaf spot for a period of three years under field condition. The percent disease index (PDI) was recorded during peak season of the foliar diseases. Out of eighty-five varieties studied, ten varieties were highly resistant and eight were resistant to powdery mildew; six varieties were immune and seventy-eight varieties were highly resistant to Myrothecium leaf spot; sixty varieties were highly resistant and 21 were resistant to Pseudocercospora leaf spot; forty four varieties were highly resistant to sooty mold and two varieties were immune and fifty-eight were highly resistant to bacterial leaf spot. Lowest cumulatative disease index was observed in M. multicaulis (7.28) followed by Thailand lobed (7.85) and Italian mulberry (8.06).

Effect of GlycinecinA on the Control of Bacterial Leaf Spot of Red Pepper and Bacterial Leaf Blight of Rice

  • Jeon, Yong-Ho;Moonjae Cho;Cho, Yong-Sup;Ingyu Hwang
    • The Plant Pathology Journal
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    • 제17권5호
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    • pp.249-256
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    • 2001
  • Xanthomonas axonopodis pv. glycines 8ra produces a bacteriocin called glycinecinA, which specifically inhibits the growth of bacteria belonging to Xanthomonas species. GlycinecinA was produced by culturing Escherichia coli DH5 containing biosynthetic genes for glycinecinA, and was tested for its control effect against X. vesicatoria on red pepper and X. oryzae pv. oryzae on rice. The bacteriocin activity was much higher in the cell extract than in the supernatant. It reached a maximum level at the stationary phase, ws maintained up to 2 months at room temperature and approximately 10 months at $4^{\circ}$. The optimum concentration of glycinecinA for the control in the greenhouse and in the field was 12,800 AU/ml. In this study, the activity of glycinecinA on rice and red pepper leaves continued for 7-8 days, during which the pathogen populations remained at low levels. Bacterial leaf spot of red pepper and bacterial leaf blight of rice were significantly reduced by the bacteriocin treatments. The control efficacy was as high as, or even higher than, the chemical treatment of copper hydroxide. These results suggest that the bacteriocin is a potential control agent for bacterial diseases.

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Erwinia chrysanthemi에 의한 Ivy-aureus (Scindapsus aureus)의 세균성 갈색부패병 (Bacterial Brwon Rot of Ivy-aureus (Scindapsus aureus) Caused by Erwinia chrysanthemi)

  • 최재을;한광섭
    • 한국식물병리학회지
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    • 제10권4호
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    • pp.336-338
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    • 1994
  • In 1991, the leaf brown spot of ivy-aureus (Scindapsus aureus) was found in Taejon and Seoul, Korea. The symptoms were appeared as dark-brown spots. The lesions were often surrounded by yellowish halos. These spots were enlarged to circular or elliptical in shape and dark-brown to black in color with slightly elevated in margin and sunken in center. The pathogenic bacteria were isolated from the diseased leaf of ivy-aureus were identified as Erwinia chrysanthemi on the basis of bacterial characteristics therefore, we would like to propose to the name of ivy-aureus disease caused by E. chrysanthemi as“bacterial brown rot of ivy-aureus”hereafter.

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그린키위 품종 헤이워드와 골드키위 품종 해금의 주요 병 발병률 (Incidence Rates of Major Diseases on Green-Fleshed Kiwifruit cv. Hayward and Yellow-Fleshed Kiwifruit cv. Haegeum)

  • 김경희;고영진
    • 식물병연구
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    • 제24권3호
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    • pp.175-181
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    • 2018
  • 2013년과 2014년 자연감염된 과수원에서 재배되는 국산 골드키위 품종인 해금에서 발생하는 궤양병, 세균성점무늬병과 과실무름병의 발병률을 그린키위 품종인 헤이워드와 비교하였다. 2013년과 2014년 P. syringae pv. actinidiae biovar 2 (Psa2)에 자연감염된 키위 과수원에서 함께 재배되고 있는 헤이워드 품종에서궤양병발병률은각각18.5%와17.3%인반면에해금 품종에서 궤양병 발병률은 1.2%와 0%였다. 2013년과 2014년 A. valerianellae에 의한 세균성점무늬병 발병률은 63.5%와 16.2%였으나 해금 품종에서는 전혀 발병되지 않았다. 2013년 관행방식에 의해 함께 재배되고 있는 과수원에서 헤이워드와 해금 품종에서 과실무름병 평균 발병률은 각각 24.2%와 6.3%였으며 2014년에는 각각 20.5%와 4.4%였다. 두 품종 모두에서 과실무름병을 일으키는 가장 중요한 병원균은 B. dothidea로 확인되었다.

멕시코와 네팔도입 고추 유전자원의 두 가지 점무늬병에 대한 저항성 (Resistance to Two Leaf Spot Diseases of Pepper Genetic Resources Introduced from Mexico and Nepal)

  • 조은형;김정훈;전수경;이지선;김병수
    • Current Research on Agriculture and Life Sciences
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    • 제23권
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    • pp.43-51
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    • 2005
  • 멕시코와 네팔에서 수집한 고추 유전자원 50점과 이병성 및 저항성 대조품종에 Stemphylium solani와 S. lycopersici 의 혼합접종으로 흰별무늬병(gray leaf spot)에 대한 저항성을 검정하고, 살균제를 살포하여 회복시킨 다음 다시 Xanthomonas campestris pv. vesicatoria를 접종하여 더뎅이병에 대한 저항성을 검정하였다 더뎅이병에는 KC866, KC872, KC902, KC905이 이미 알려진 KC43, KC47, KC220, KC319, KC320, KC380 등과 함께 저항성으로 나타났다. 더뎅이병, bacterial spot)에는 KC897이 이미 저항성으로 보고된 KC177(PI163192)보다 발병이 적어 가장 우수한 것으로 나타났으며 이어서 네팔에서 도입된 KC889, KC896, KC898이 저항성으로 나타났다.

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Reclassification of Xanthomonas Isolates Causing Bacterial Leaf Spot of Euphorbia pulcherrima

  • Li, Bin;Yu, Rongrong;Shi, Yu;Su, Ting;Wang, Fang;Ibrahim, Muhammad;Xie, Guanlin;Wang, Yanli;Sun, Guochang
    • The Plant Pathology Journal
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    • 제27권4호
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    • pp.360-366
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    • 2011
  • Bacterial leaf spot of Euphorbia pulcherrima has been reported in many countries. Characterization by polyphasic approaches indicated that the isolates from India, USA and New Zealand could be distinguished based on rep-PCR profiles and gyrB phylogenies, while the Chinese isolates should be ascribed to Xanthomonas axonopodis pv. poinsettiicola.

Clavibacter michiganensis subsp. michiganensis에 의한 고추 궤양병 (Occurrence and Distribution of Bacterial Canker of Red Pepper Caused by Clavibacter michiganensis subsp. michiganensis)

  • 이승돈
    • 식물병과 농업
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    • 제5권2호
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    • pp.105-110
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    • 1999
  • Bacterial leaf spot by Xanthomonas campestris pv. vesicatoria has been known to cause serious problem in red pepper in Korea. However recent survey showed that most smptoms in the leaves were mixed with two different symptoms one was leaf spot and the other was canker. bacteria isolated from canker were identified as Clavibacter michiganensis subsp. michiganensis on the basis of biochemical and physiological characteristics. The causal bacteria were non-motile rod-shaped and Gram-positive. The lesions on pepper leaves appeared at first as small blisters or pimple-like white spots which enlarged in size at a later stage. The centers of some of the spots became necrotic and brown and were surrounded by a white halo. Pathogenicity tests were performed on pepper cv. Alchan seedling by spraying of bacterial suspension. During 1997 and 1998 total 17% of 527 fields surveyed were infected by C. michiganensis subsp. michiganensis. The canker of red pepper caused by C. michiganensis subsp. michiganensis was first identified in this study in Korea, and new name "gueyangbyung" was tentatively given to the disease.

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Development of a Model to Predict the Primary Infection Date of Bacterial Spot (Xanthomonas campestris pv. vesicatoria) on Hot Pepper

  • Kim, Ji-Hoon;Kang, Wee-Soo;Yun, Sung-Chul
    • The Plant Pathology Journal
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    • 제30권2호
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    • pp.125-135
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    • 2014
  • A population model of bacterial spot caused by Xanthomonas campestris pv. vesicatoria on hot pepper was developed to predict the primary disease infection date. The model estimated the pathogen population on the surface and within the leaf of the host based on the wetness period and temperature. For successful infection, at least 5,000 cells/ml of the bacterial population were required. Also, wind and rain were necessary according to regression analyses of the monitored data. Bacterial spot on the model is initiated when the pathogen population exceeds $10^{15}cells/g$ within the leaf. The developed model was validated using 94 assessed samples from 2000 to 2007 obtained from monitored fields. Based on the validation study, the predicted initial infection dates varied based on the year rather than the location. Differences in initial infection dates between the model predictions and the monitored data in the field were minimal. For example, predicted infection dates for 7 locations were within the same month as the actual infection dates, 11 locations were within 1 month of the actual infection, and only 3 locations were more than 2 months apart from the actual infection. The predicted infection dates were mapped from 2009 to 2012; 2011 was the most severe year. Although the model was not sensitive enough to predict disease severity of less than 0.1% in the field, our model predicted bacterial spot severity of 1% or more. Therefore, this model can be applied in the field to determine when bacterial spot control is required.

접종방법에 따른 딸기모무늬병원균의 발병도 검증 및 친환경 방제 효과 (Disease Severity of Angular Leaf Spot Disease by Different Inoculation Method and Eco-Friendly Control Efficacy in Strawberry.)

  • 김다란;강근혜;조현지;윤혜숙;명인식;곽연식
    • 농약과학회지
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    • 제20권1호
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    • pp.35-40
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    • 2016
  • 딸기 세균성모무늬병은 딸기를 기주로 하여 발생하며 큰 피해를 발생시킨다. 병원균의 전반은 관수의 형태, 감염된 모주의 이용 그리고 작업자에 의해 이루어지며 현재까지 명확한 화학적방제법이 개발되어 있지 않다. 2010년, 국내의 모무늬병원균에 대한 최초 보고에 따르면 병징으로서 잎 뒷면에 수침상의 각진 병반이 형성되며 습도가 높고 적합한 환경에서 세균침출액을 형성하게 되고 또한 진전된 경우 잎에서 적갈색의 병반이 형성된다고 보고하였다. 현재까지 이루어진 연구에 따르면 딸기 세균성모무늬병에 대하여 두 가지 품종이 저항성을 지니고 있다는 연구 결과가 있으며 감염된 포장에서는 수확량의 10%를 감소를 나타낸다고 알려져 있다. 그러나 이와 같은 모무늬병원균에 대한 국내에서의 활발한 연구가 이루어져 있지 않은 상황이다. 이에 본 연구는 딸기 모무늬병에 대하여 원인병원균이 Xanthomonas fragariae 병원균에 의하여 발생됨을 보고하는 바이며 병원성검증실험 진행한 결과 국내의 딸기재배 품종인 매향과 설향 중 매향이 감수성을 나타냄을 확인하였다. 또한 NaDCC처리시 98%이상의 방제가가 확인되었으므로 친환경방제제로서의 가능성을 제시하며 이러한 연구결과들은 국내에 발생되어있는 딸기 세균성모무늬병에 대하여 기초적 자료로서 보고하는 바이다.