• 제목/요약/키워드: diseased field

검색결과 139건 처리시간 0.024초

Phytophthora cactorum에 의한 백합 역병 (Stem Rot of Lily(Lilium L.) Caused by Phytophthora cactorum in Korea)

  • 류경열;김령희;이영희;허노열
    • 한국식물병리학회지
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    • 제14권5호
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    • pp.458-462
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    • 1998
  • Stem rot symptomof lily caused by Phytophthora was observed in Chilkok, Korea in 1997. Oogonia of Phytophthora were abundantly developed on epidermal tissues of stem and leaves of the diseased plants. The casual fungus was identified as Phytophthora cactorum based on their cultural and morphological characteristics. Sporangia were markedly papillate and the shape was broadly spherical to ovoid both on agar and in water. The size was 28~44$\times$20~28 ${\mu}{\textrm}{m}$ (av. 36~24) and a short pedicel was attached to each sporangium. The fungus was homothallic and oogonia were 28~32 ${\mu}{\textrm}{m}$ (av. 30) in size and slightly yellow. Antheridia were paragynous and spherical or irregularly club shaped. Optimal temperature for mycelial growth was 25~27$^{\circ}C$. The fungus did not grow under 6$^{\circ}C$ and over 34$^{\circ}C$. The fungus was highly pathogenic to three cultivars of lily. Symptom was developed at 4-day after artificial inoculation with zoospores (103 cell/ml) on the stem of lily. The symptom was identical to those produced by natural infection in the field and the plant was blighted within 14 days after inoculation.

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Dynamic response of heat and mass transfer in blood flow through stenosed bifurcated arteries

  • Charkravarty S.;Sen S.
    • Korea-Australia Rheology Journal
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    • 제17권2호
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    • pp.47-62
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    • 2005
  • The present study deals with a mathematical model describing the dynamic response of heat and mass transfer in blood flow through bifurcated arteries under stenotic condition. The geometry of the bifurcated arterial segment possessing constrictions in both the parent and the daughter arterial lumen frequently appearing in the diseased arteries causing malfunction of the cardiovascular system, is formulated mathematically with the introduction of the suitable curvatures at the lateral junction and the flow divider. The blood flowing through the artery is treated to be Newtonian. The nonlinear unsteady flow phenomena is governed by the Navier-Stokes equations while those of heat and mass transfer are controlled by the heat conduction and the convection-diffusion equations respectively. All these equations together with the appropriate boundary conditions describing the present biomechanical problem following the radial coordinate transformation are solved numerically by adopting finite difference technique. The respective profiles of the flow field, the temperature and the concentration and their distributions as well are obtained. The influences of the stenosis, the arterial wall motion and the unsteady behaviour of the system in terms of the heat and mass transfer on the blood stream in the entire arterial segment are high­lighted through several plots presented at the end of the paper in order to illustrate the applicability of the present model under study.

참깨 병해연구 I. 참깨 역병의 발생에 대하여 (Studies on Sesame Diseases in Korea I. Incidences of Phytophthora Blight)

  • 조의규;허노열;최성호;이승찬
    • 한국응용곤충학회지
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    • 제21권4호
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    • pp.211-215
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    • 1982
  • 1981년 전북고창, 전남영광, 경북달성, 경남진양 지역에서 참깨병해의 발생과 피해를 조사한 결과 참깨역병의 피해가 가장 심하였다. 참깨역병의 발생은 포장에 따라 차이가 컸으며 발병이 심한 포장에서는 발병주율이 $61\%$나 되었다. 참깨역병을 일으키는 병원균 Phytophthora spp.는 유주자낭의 형태적특성과 참깨에 대한 특이적인 병원성에 의하여 Phytophthora nocitianae var. parasitica (Dastur) Waterhouse로 동정되었다. 참깨역병의 병징은 줄기가 암갈색으로 변색, 부패되어 식물체가 도태고사하는 특징을 보였다.

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Occurrence of Web Blight in Soybean Caused by Rhizoctonia sol ani AG-l(IA) in Korea

  • Kim, Wan-Gyu;Hong, Sung-Kee;Han, Seong-Sook
    • The Plant Pathology Journal
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    • 제21권4호
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    • pp.406-408
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    • 2005
  • Web blight symptoms were frequently observed on soybean plants grown in a farmer's fields located in Jincheon in Korea during a disease survey in August, 2005. Incidence of the disease was $5-20\%$ infected plants in two of four soybean fields investigated. A total of 31 isolates of Rhizoctonia sp. were obtained from leaves, leaf petioles, and pods of diseased soybean plants. The isolates were identified as Rhizoctonia solani AG-l(IA) by anastomosis test and based on the morphological and cultural characteristics. Three isolates of R. solani AG-l(IA) were tested for pathogenicity to five cultivars of soybean by artificial inoculation. All the isolates induced blight symptoms on the leaves of soybean and formed sclerotia on the lesions, which were similar to those observed in the field. The pathogenicity tests revealed that all the soybean cultivars tested were susceptible to the pathogen. There was no difference in the pathogenicity among the isolates. The present study first reveals that R. solani AG-l(IA) causes web blight of soybean in Korea.

역병의 감염 여부에 따른 토양 내 진균 분포 (Analysis of Soil mycoflora in Phytophthora Infested and Non-Infested Fields)

  • 이선주;김종식;홍승범
    • 한국토양비료학회지
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    • 제33권2호
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    • pp.121-126
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    • 2000
  • 불건전 토양과 건전 토양의 환경을 이해하기 위해 자연적으로 역병에 감염되거나 감염되지 않은 고추와 토마토 시설재배지의 비근권토양, 근권토양, 근면을 채취하고 연구하였다. 시료는 경상남도의 시설재배지에서 1999년 4월에 채집되었으며, 진균의 분리는 희석평판법을 이용하였다. 각 작물 별 재배지에서 25 종의 진균이 분리되었으며 건전 시료보다는 감염 시료에서, 근권이나 근면토양보다 비근권토양에서 더 많은 수의 종이 분리되었다. 역병이 감염되지 않은 시료에서만 Trichoderma sp.가 분리되었으며 각 작물의 서식지별로 분리된 진균의 수는 다양하였다.

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경남 남부지역 양식어류 질병에서 항생제 감수성에 관한 연구 (The Study on Fish Diseases with Reference to Bacterial Susceptibility to Antibiotics in the Southern Area of Kyeognam)

  • 허정호;정명호;조명희;김국헌;이국천;김재훈;정태성
    • 한국임상수의학회지
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    • 제19권1호
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    • pp.19-22
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    • 2002
  • The examination with 96 bacteria isolates for antibiotics susceptibility was resulted in exploring many antibiotics resistance isolates from the diseased fishes. Vibrio sp. isolates were demonstrated over 90% resistances for Penicillin (P), Amoxicillin (Amc), Erythromycin (I), Colistin (CL). Streptomycin (S). Novobiocin (NV) and Neomycin(N), these isolates were, however, appeared over 80% susceptibilities for Norfloxacin (Nor), CE and UB. In Edwardsiella tarda case, 90 to 100% high resistance was observed for P, Doxycycline (Do), Tetracyclin (Te), Oxytetracycline (T), E, CL, Sulfamethoxasoletrimetoprim (SXT), S, Oxolinic acid (OA), W, Neomycin(N), on the contrary, 90 to 100% high susceptibilities was found for Amc, Nor, Ciprofloxacin (Cip), Orbifloxacin (ORB), Enrofloxacin (ENR), Flumeguine (UB) and NA. CL, Pefloxacin (PEF),S, Flumeguine (UB), OA, NA, NV N was exhibited 90 to 100% resistances for Streptococcus sp., on the other hand, 100% susceptible to AMC and 80% susceptible to Do, Te, ENR and UB was recognised. Lastly, Photobacterium damsela subsp. piscicida was showed 100fe susceptible to Amc and 86% susceptible to NOR, CIP ENR and UB. As a consequence, fish bacterial pathogens isolated from Kyeongnam area, especially Tongyeong-si, Geoje-si, and Goseong-gun, were showed highly resistant to a variety of antibiotics available in the field.

Distal Aortic Remodeling after Type A Dissection Repair: An Ongoing Mirage

  • Rathore, Kaushalendra Singh
    • Journal of Chest Surgery
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    • 제54권6호
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    • pp.439-448
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    • 2021
  • Remodeling is a commonly encountered term in the field of cardiothoracic surgery that is often used to describe various pathophysiological changes in the dimension, structure, and function of various cardiac chambers, including the aorta. Stanford type A or DeBakey type 1 aortic dissection (TAAD) is a perplexing pathologic condition that can present surgical teams with the need to navigate a maze of complex decision-making. Ascending or hemi-arch replacement leaves behind a significant amount of distal diseased aortic tissue, which might have a persistent false lumen or primary or secondary intimal tears (or communications between lumina), which can lead to dilatation of the aortic arch. Unfavorable aortic remodeling is a major cause of distal aortic deterioration after the index surgery. Cardiac surgeons are aware of post-surgical cardiac chamber remodeling, but the concept of distal aortic remodeling is still idealized. The contemporary literature from established aortic centers supports aggressive management of the residual aortic pathology during the index surgery, and with continuing technical advancements, endovascular stenting options are readily available for patients with TAAD or for complicated type B aortic dissection cases. This review discusses the pathophysiology and treatment options for favorable distal aortic remodeling, as well as its impact on mid- to long-term outcomes following TAAD repair.

Effect of Bacterial Wilt on Fungal Community Composition in Rhizosphere Soil of Tobaccos in Tropical Yunnan

  • Zheng, Yuanxian;Wang, Jiming;Zhao, Wenlong;Cai, Xianjie;Xu, Yinlian;Chen, Xiaolong;Yang, Min;Huang, Feiyan;Yu, Lei;He, Yuansheng
    • The Plant Pathology Journal
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    • 제38권3호
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    • pp.203-211
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    • 2022
  • Bacterial wilt, which is a major soil-borne disease with widespread occurrence, poses a severe danger in the field of tobacco production. However, there is very limited knowledge on bacterial wilt-induced microecological changes in the tobacco root system and on the interaction between Ralstonia solanacearum and fungal communities in the rhizosphere soil. Thus, in this study, changes in fungal communities in the rhizosphere soil of tobaccos with bacterial wilt were studied by 18S rRNA gene sequencing. The community composition of fungi in bacterial wilt-infected soil and healthy soil in two tobacco areas (Gengma and Boshang, Lincang City, Yunnan Province, China) was studied through the paired comparison method in July 2019. The results showed that there were significant differences in fungal community composition between the rhizosphere soil of diseased plants and healthy plants. The changes in the composition and diversity of fungal communities in the rhizosphere soil of tobaccos are vital characteristics of tobaccos with bacterial wilt, and the imbalance in the rhizosphere microecosystem of tobacco plants may further aggravate the disease.

Complete sequence of genome RNA of Pepper mottle virus Korean isolate

  • H.I. Yoon;J, Y. Yoon;Park, G.S.;Park, J.K.;K.H. Ryu
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.147.2-148
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    • 2003
  • Complete nucleotide sequence of genome RNA of a Korean isolate of Pepper mottle virus (PepMoV-Vb) from field-collected diseased paprika (Capsicum annuum var grossum) was determined in this study. Symptoms of isolates of PepMoV were divided largely into two groups, vein banding (Vb) and vein clearing (Vc) patterns. PepMoV-Vb RNA consists of 9,640 nucleotides excluding the poly(A) tail. A single open reading frame was identified beginning at nucleotide position 169 encoding a polyprotein of 3024 amino acids which is typical of the Potyvirus genus. The complete nucleotide sequence and coding regions of PepMoV-Vb were compared to that of 11 potyviruses within the genus Potyvirus. The overall nucleotide sequence identity was 94.7 and 94.1% identical to PepMoV-C and PepMoV-FL, respectively. Full-length cDNAs of PepMoV-Vbl were synthesized from purified viral RNAs by RT-PCR and their genome structure was analysed by RFLP analysis. This is the first report on complete nucleotide sequence of PepMoV isolated from paprika in Korea.

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Potential of Curvularia sp. DBB2003 as mycoherbicide for monochoria.

  • Kim, Jae-Su;Lee, Han-Young;Jang, Seung-Sik;Chung, Bong-Jin
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.111-111
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    • 2003
  • Several fungal isolates were isolated from diseased monochoria(Monochoria vaginalis, weed of paddy field), which has an resistance to sulfonyl urea(S.U.) herbicide, and were evaluated in the laboratory and greenhouse as potential mycoherbicide. Eight fungi, Alternaria sp., Colletotrichum sp., Curvularia sp., Paenicillium sp and etc. were observed in the isolates. Pathogenicity testing were done on the monochorias in the greenhouse. Monochorias were inoculated with suspensions containing conidia of each isolate at the rates of 1.0 ${\times}$ 10$\^$5/ conidia/ml and 0.1% Tween 80 with hand-gun sprayer. Curvularia sp. and an unidentified fungal isolate caused 90-95% mortality on the monochorias 15∼20 days after inoculation. However the other isolates induced slight symptom of disease on the monochorias. In the early stage of disease development sun-burn appearance was shown at the infected site and the last infected leaves and stems were withered to death. Subsequently the pathogenicity on the rice was evaluated with above two effective isolates. From the test an unidentified isolate showed pathogenicity on the rice but Curvularia sp., named as DBB2003, didn't. Now the mass production and formulation using Curvularia sp. DBB2003 are in progress and the field test will be followed. Combination product with Curvularia sp. DBB2003 and chemical herbicide will be more effect to control the monochoria resisted on S.U. herbicide and need to be further tested.

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