• 제목/요약/키워드: bacterial blight.

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Xanthomonas axonopodis pv. eucalyptorum pv. nov. Causing Bacterial Leaf Blight on Eucalypt in Brazil

  • Ferraz, Helvio Gledson Maciel;Badel, Jorge Luis;da Silva Guimaraes, Lucio Mauro;Reis, Bruna Paolinelli;Totola, Marcos Rogerio;Goncalves, Rivadalve Coelho;Alfenas, Acelino Couto
    • The Plant Pathology Journal
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    • 제34권4호
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    • pp.269-285
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    • 2018
  • Bacterial leaf blight is a major disease of eucalypt, especially under nursery conditions. Different bacterial species have been associated with the disease in several countries, and despite its importance worldwide, it is not clear to date whether similar disease symptoms are caused by the same or by different etiological agents. In this study, 43 bacterial strains were isolated from blighted eucalypt leaves collected in different geographic areas of Brazil and inoculated onto a susceptible eucalypt clone. Polyphasic taxonomy, including morphological, physiological, biochemical, molecular, and pathogenicity tests showed that only certain strains of Xanthomonas axonopodis caused symptoms of the disease. Strains varied in their aggressiveness, but no correlation with geographic origin was observed. MLSA-based phylogenetic analysis using concatenated dnaK, fyuA, gyrB and rpoD gene sequences allocated the strains in a well-defined clade, corresponding to Rademarker's group RG 9.6. Inoculation of nineteen plant species belonging to seven botanical families with representative strain LPF 602 showed it to be pathogenic only on Eucalyptus spp, and Corymbia spp. Based on distinct biochemical and pathogenic characteristics that differentiate the eucalypt strains from other pathovars of the X. axonopodis species, here we propose their allocation into the new pathovar X. axonopodis pv. eucalyptorum pv. nov.

삼요소시비량과 수도생육상태가 백엽고병(벼, 흰빛잎마름병) 발병에 미치는 영향 (Effects of N,P,K fertilizer levels and growth condition on the development of Bacterial leaf blight in rice plants)

  • 김정화;조용섭
    • 한국응용곤충학회지
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    • 제9권1호
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    • pp.7-13
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    • 1970
  • 1. 본 병에 강한 감수성품종인 금남풍을 사용하였고, Xanthomonas oyzae 6526 균주를 반합성감자배양기에 이식, $28^{\circ}C$에 3일간 사면배양한 뒤 균부유액을 만들어 상엽 상단부에 단침접종하고 14일 뒤에 확대된 병반길이를 조사하였다. 시험구설정은 3요소를 각각 무비$\cdot$표준비$\cdot$배비의 3개 수준으로 시비하여 총 27개구를 설정하고 3반복 임의배치하였다. 2. 질소질비료는 인산$\cdot$가리의 시용량에 크게 좌우되지 않았고 증시할 수록 발병이 심하였다. 3. 인산은 표준량시용하였을 때만 다소 발병억제효과의 경향이 있었으나 배비하게 되면 오히려 무비구보다도 터 발병이 촉진되었다. 4. 가리를 표준양시용하였을에 발병이 현저히 줄어들으나 시용량과 비례하지 않았고 배비하면 인산에서 처럼 다시 발병이 촉진되었다. 5. 출수시기가 늦어질 수록, 그리고 수수가 많을수록 발병이 심하였다. 6. 삼요소를 다같이 표준량시용하였을 때가 가장 발병이 적었는데, 작물의 영양조성은 비료의 종류, 시용량, 시용방법에 따라 좌우되며 발병도 기주식물의 조성과 밀접한 관계가 있으므로 시비법을 적절히 조절하면 본 병의 피해를 많이 감소시킬 수 있을 것으로 기대된다.

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Enhancement of Biocontrol Activity of Antagonistic Chryseobacterium Strain KJ1R5 by Adding Carbon Sources against Phytophthora capsici

  • Kim, Yu-Seok;Jang, Bo-Ra;Chung, Ill-Min;Sang, Mee-Kyung;Ku, Han-Mo;Kim, Ki-Deok;Chun, Se-Chul
    • The Plant Pathology Journal
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    • 제24권2호
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    • pp.164-170
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    • 2008
  • Carbon utilization by Chryseobacterium strain KJ1R5 was studied to enhance its biocontrol activity against Phytophthora capsid. Chryseobacterium strain KJ1R5 has previously been shown to control Phytophthora blight of pepper (Capsicum annuum L.). Strain KJ1R5 could utilize carbon sources such as L-arabinose, D-cellobiose, ${\beta}-lactose$ and D-galactose well. P. capsici could utilize D-glucose well, showing the absorbencies ranged from 0.577 to 0.767 at 600nm. When 2% L-arabinose, which could only be utilized by the bio-control strain KJ1R5, was amended into the bacterial suspension, the efficacy of biological control increased. Among the amendments of various carbon sources into bacterial suspension, L-arabinose and D-(+)-glucose significantly enhanced biological control activity, resulting in a reduction of disease incidence to 6.9%, compared to 21.9% for the strain KJ1R5 alone and 81.3% for P. capsici inoculation alone, indicating that amendment with specific carbon sources could increase the biological control activity.

벼 아소미노리 교배조합 품종의 벼흰잎마름병 저항성 (Resistance of Varieties Bred by Crossing with Asominori to Bacterial Leaf Blight)

  • 심재성
    • 한국자원식물학회지
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    • 제10권2호
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    • pp.128-134
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    • 1997
  • This study was conducted to test on the resistance of varieties bred by crossing with Asominori to bacterial leaf blight. Nakdongbyeo and Dongjinbyeo which were susceptible to HB 9011, 8 resistant varieties including Ilmibyeo derived from Asominori and Asominori, Hwangok, 13 varieties including Chukoku 45 which were resistance to HB 9011, HB 9022 and HB 9033 were used to screen their res ponce depending on the various screening methods such as the true resistance, the secondary infection resistance and the disease common field test methods, and the results are as follows: Among 13 varieties tested, 11 varieties including llmibyeo showed tme resistance to HB 9011. Less than 1.0cm of disease lesion were developed on these varieties. Disease lesion was not developed on most of the Asominori lines including Daechongbyeo against IIB9011 and 1lmibyeo was also resistance to HB 9011, on this variety disease lesion area rate was 1.2%, and 7 varieties including Hwajinbyeo showed field resistance to HB 9022. Disease lesion area rate were 19.6% on Nakdongbyeo. 15.6% on Dongjinbyeo, from 3.0% to 2.4% on Asominori lines, and 0.5% on the Asominori when screened at disease common area. Disease was not developed on Keumnambyeo. Significant correlation coefficiences were found between the results from the test methods of the true resistance, the field resistance ancl the field resistance at disease common field tests on Asominori lines, but in some cases, even the varieties on which disease lesions developed, showed field resistance to HB 9022 and HB 9033.

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