• 제목/요약/키워드: white spot

검색결과 203건 처리시간 0.029초

배나무 검은무늬병균(Alternaria kikuchiana Tanaka)에 병원성분화와 저항성품종의 이병화 (Differentiation in Pathogenicity of Alternaria kikuchiana Tanaka, Black Spot Fungus of Pear, and Conversion of Resistant Varieties into Susceptible ones)

  • 기운계;박서기;조백호;김기청
    • 한국응용곤충학회지
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    • 제23권1호
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    • pp.7-14
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    • 1984
  • 전남 나주지방에서 만연하고 있는 검은무늬 병 유사증상을 조사한 결과는 다음과 같다. 1. 병원균은 Alternaria kikuchiana Tanaka로 동정되었다. 2. 5월 하순부터 발병되기 시작하여 6월 하순$\~$7월상순에 가장 심하였고 9월 상순에 다시 증가하였다. 3. 이병은 조사품종들의 성엽에 발생하였으나 20세기에서만 유엽에 많이 발생하였다. 5. 이 병은 나주시험장에 있는 거의 모든 품종에 발병하였는데 종래 저항성품종으로 알려진 신흥, 만3길등은 가장 심한 발병을 보였고 이병성품종으로 알려진 조옥, 박다청등은 약간 발병하거나, 전혀 발병하지 않았다. 6. 이상의 결과로 미루어 보아 검은무늬병균에 병원성의 분화가 일어난 것으로 판단된다.

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Characterization of North American Ginseng Rust-Spot and the Effects of Ethephon

  • Campeau, Cindy;Proctor, John T.A.;Murr, Dennis P.;Schooley, Jan
    • Journal of Ginseng Research
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    • 제27권4호
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    • pp.188-194
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    • 2003
  • Rust-spot on North American ginseng roots (Panax quinquefolius L.) is considered a physiological, not a pathological disorder. Ginseng rust-spot starts as an orange spot on the surface of the root and may spread forming a sunken, round to irregular lesion. 5 mm in diameter. Pieces of root, 7 mm in length and containing a rust-spotted lesion, were embedded in agar and sectioned using a vibratome. These sections and hand sections, cut with a two-sided razor blade, were examined using fluorescence microscopy. The 4-5 cell layers of the periderm were destroyed in the area of the lesion and orange substance:, were deposited in and around the lesion. Sections stained with vanillin-HCI and viewed using bright field microscopy confirmed that the orange substances were phenolic compounds. Scanning electron micros-copy showed that the periderm had pulled away from the root, or was completely destroyed, in the area of the lesion. The smooth surface of the lesion indicates the deposition of phenolic compounds in surrounding cells as a wound response. Roots sprayed or dipped in ethephon (1500 mgㆍL$^{-1}$ ) developed rust-spots, more so at 21$\pm$2$^{\circ}C$ than at 3$\pm$0.2$^{\circ}C$. Roots held at 21$\pm$2$^{\circ}C$ were yellowish and developed white cell proliferations. Comparable control roots also developed rust-spots likely due to the high undecomposed organic matter content of the incubation soilless mix.

Cristulariella moricola에 의한 네군도단풍 둥근무늬낙엽병 (Zonate Leaf Spot of Acer negundo Caused by Cristulariella moricola in Korea)

  • 조성은;박지현;이상현;이향범;신현동
    • 식물병연구
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    • 제18권1호
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    • pp.45-48
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    • 2012
  • 저온다습한 날씨가 지속된 후의 2011년 8월 초순에 경기도 동두천시 소요산에서 겹둥근무늬와 조기낙엽 증상을 나타내는 네군도단풍이 발견되었다. 병든 잎의 뒷면에서 원뿔 모양이며 흰색의 분생포자가 다수 관찰되었다. 현미경 검경을 통하여 형태적 특징을 검토한 결과, 이 증상의 원인균은 Cristulariella moricola로 동정되었다. 상대습도 100% 및 $18{\pm}2^{\circ}C$의 조건에서 인공접종을 통하여 이균의 병원성을 증명하였다. 한편, 분리 균주의 internal transcribed spacer 영역의 염기서열을 분석하고 NCBI에 등록된 균의 염기서열과 비교함으로써 이 균이 C. moricola임을 증명하였다. 네군도단풍에 C. moricola의 감염에 의해 발생한 둥근무늬낙엽병은 우리나라에서 최초의 기록이다.

표면조도 특성에 따른 저항 점 용접성 평가 및 너깃 형성 고찰 (Evaluation on Resistance Spot Weldability and Nugget Formation of Surface Roughness Treated Steel Sheet)

  • 김기홍;최영민;김영석;임영목;유지훈;강남현;박영도
    • Journal of Welding and Joining
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    • 제26권5호
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    • pp.79-89
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    • 2008
  • With the increased use of surface textured steel sheet in body-in-white assembly, resistance spot weldability of these steels is considered to be an important subject. This study evaluated nugget formation and weldability by measuring dynamic resistance with various weld pressure, current, and weld time for steel sheet with two different surface roughnesses. The surface roughness for T-H steel ($R_{a}=1.70\;{\mu}m$) was higher than that for T-L steel ($R_{a}=1.33\;{\mu}m$), and resulted in increased contact resistance and heating for T-H steel spot welding. Therefore, at low weld current and weld cycle ranges, the T-H steel showed better weldability over the T-L steel. The evaluations of weld interface showed that the fusion zone in the T-H steel sheet was continuous in contrast to discontinuous fusion zone for T-L steel sheet at the same welding conditions. A comparison of dynamic resistance and tensile-shear strength (TSS) between T-H and T-L steel sheet suggested that high surface roughness provided larger heating at early cycle of welding and larger TSS.

사향의 크로마토그램 패턴 분석을 통한 품질비교 연구 (Quality comparison of musk products using a chromatographic pattern analysis)

  • 조종운;가오단;강종성;정효원;박용기
    • 대한본초학회지
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    • 제36권4호
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    • pp.41-50
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    • 2021
  • Objectives : This study is to check the quality of Moschus products in Korean markets using a chromatographic analysis. Methods : We collected musk products, two genuine products from Russia (A, B), two authentic products from Hong Kong (C) and Korea (D), the Ministry of Food and Drug Safety (MFDS) standard (E), and two fire ants products (E, F). Results : For identification, TLC analysis of 60% ethanol extracts of each product showed that A, B, C, and E have the suitable patterns before color development at 365 nm UV light for the MFDS regulation in Korea. A clear red spot was observed from the E at Rf 0.6 with 365 nm UV light after color development, but this spot was not found in A and B. For the purity test, a distinct violet spot with Rf 0.87 was observed from the A and B in TLC analysis of methanol extracts of each product at white light, however, this spot was not matched with the impurities of E and F. In HPLC-UV pattern analysis, a similar peak pattern was shown in A, B and E, and similar peaks were observed C, although the similarity was weaker than that of A, B, and E. The F and G showed different peak patterns compared with the peak patterns of other samples. Conclusions : Hence, it is considered that the test methods need flexibility in application for identification and purity test depending on the type of sample.

표면조도처리 된 합금화 용융아연도금강판의 저항 점 용접성 (Resistance Spot Weldability of Surface Roughness Textured Galvannealed Steel Sheets)

  • 박상순;김기홍;강남현;김영석;임영목;최영민;박영도
    • 대한금속재료학회지
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    • 제46권8호
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    • pp.495-505
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    • 2008
  • With the high proportion of zinc coated steels in body-in-white assembly, newly developed surface roughness textured galvannealed steel sheets have been introduced. In this study, zinc coated and surface roughness textured steel sheets were welded by resistance spot welding to investigate its weldability including electrode wear test. Based on the results of tensile-shear test, nugget diameter changes, and electrode tip growth test, it was clear that both surface roughness textured steels (GA-T and GA-E) showed good weldability. Also, there was no large difference in weldability and electrode wear behavior between GA-T and GA-E steels which have different surface roughness morphology. An analysis of electrode degradation showed Fe and Zn penetration through the electrode tip surface at 2400 welds reached $55{\sim}60{\mu}m$ and $75{\sim}80{\mu}m$, respectively. Therefore, there is no significant effect of surface roughness morphology on spot weldability of surface roughness textured galvannealed steel sheets. However, slight difference in thickness of alloying layers existing on electrode tip was found between GA-T and GA-E steels.

흰반점바이러스(WSSV)의 중화를 위한 재조합단백질 rVP466의 항혈청 생산 (Production of the Antiserum against Recombinant Envelop Protein, rVP466 for the Neutralization of White Spot Syndrome Virus (WSSV))

  • 공수정;김영진;최미란;김성구
    • 생명과학회지
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    • 제20권10호
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    • pp.1427-1432
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    • 2010
  • 본 연구는 WSSV의 재조합단백질 rVP466에 대하여 생산된 항혈청을 사용하여 WSSV에 대한 neutralization (중화) 효과를 확인하고자 수행하였다. 먼저 재조합단백질 rVP466의 생산을 위해 WSSV의 구성단백질 VP466을 암호화하는 유전자인 VP466을 포함하는 재조합 플라스미드 pCold-VP466을 제작한 다음 이것을 발현용 숙주인 E. coli RIPL에서 발현하였다. 발현된 rVP466에 대한 항혈청은 토끼를 사용하여 생산하였으며, 항원 rVP466에 대한 특이면역반응은 Western blot을 통해 확인하였다. WSSV에 대한 항혈청의 중화효과를 확인하기 위해 항혈청과 반응시킨 바이러스액($1{\times}10^4$ 배로 희석된 WSSV)을 이용하여 실험용 새우(Penaeus chinensis)에게 주사 감염을 통해 공격실험(challenge test)을 수행하였다. 실험 결과, WSSV로 공격실험한 감염대조구(positive control)의 새우들은 감염 후 17일째에 100% 누적폐사율을 보였으며, preimmune serum과 WSSV의 혼합액을 challenge한 preimmune control의 새우들은 감염 후 25일째에 83%의 누적폐사율을 보였다. WSSV와 rVP466 항혈청을 1:0.01, 1:0.1, 1:1로 혼합한 액으로 challenge한 새우들은 감염 후 25일째에 각각 73%, 53%, 46%의 누적폐사율을 보였다. 이상의 결과를 통해 WSSV가 rVP466 항혈청에 의해 농도의존적으로 neutralization됨을 확인하였으며, 이는 WSSV 감염과정에 VP466이 관여함을 나타내는 것이다.

양식대하(Penaeus chinensis) 감염 White Spot Baculovirus(WSBV)의 병원성 및 병리조직학적 특성 (Pathogenicity and Histopathological Characteristics of White Spot Baculovirus(WSBV) in Cultured Shrimp, Penaeus chinensis)

  • 허문수;손상규
    • 한국어병학회지
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    • 제14권1호
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    • pp.16-20
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    • 2001
  • WSBV에 감염된 대하의 간췌장, 림프기관, 위 그리고 심장으로부터 바이러스를 분리하여 바이러스액을 제조하였다. 수획된 바이러스액을 이용하여 병원성 시험을 실시하였다. 감염 방법에서는 주사감염, 경구감염, 침지감염순으로 병원성이 높게 나타났고 수온별 병원성에서는 $30^{\circ}C$, $25^{\circ}C$, $20^{\circ}C$, $15^{\circ}C$순으로 병원성이 높게 나타났다. 크기별 감염시험에서는 크기에 따라 폐사시기는 차이가 있지만 크기에 관계없이 강한 병원성을 나타냈다. 병리조직학적 관찰에서는 림프조직, 조혈조직, 위상피등에서 세포핵의 비대화를 관찰할 수 있었다.

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Transcriptional Analysis for Oral Vaccination of Recombinant Viral Proteins against White Spot Syndrome Virus (WSSV) in Litopenaeus vannamei

  • Choi, Mi-Ran;Kim, Yeong-Jin;Jang, Ji-Suk;Kim, Sung-Koo
    • Journal of Microbiology and Biotechnology
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    • 제21권2호
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    • pp.170-175
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    • 2011
  • This study was carried out for the molecular level identification of recombinant protein vaccine efficacy, by oral feeding against white spot syndrome virus infection, with the comparison of viral mRNA transcriptional levels in shrimp cells. For the determination of WSSV dilution ratio for the vaccination experiment by oral feeding, in vivo virus titration was carried out using different virus dilutions of virus stock ($1{\times}10^2$, $2{\times}10^2$, and $1{\times}10^3$). Among the dilution ratios, $2{\times}10^2$ diluted WSSV stock was chosen as the optimal condition because this dilution showed 90% mortality at 10 days after virus injection. Recombinant viral proteins, rVP19 and rVP28, produced as protein vaccines were delivered in shrimps by oral feeding. The cumulative mortalities of the shrimps vaccinated with rVP19 and rVP28 at 21 days after the challenge with WSSV were 66.7% and 41.7%, respectively. This indicates that rVP28 showed a better protective effect against WSSV in shrimp than rVP19. Through the comparison of mRNA transcriptional levels of viral genes from collected shrimp organ samples, it was confirmed that viral gene transcriptions of vaccinated shrimps were delayed for 4~10 days compared with those of unvaccinated shrimps. Protection from WSSV infection in shrimp by the vaccination with recombinant viral proteins could be accomplished by the prevention of entry of WSSV due to the shrimp immune system activated by recombinant protein vaccines.

새우 양식장 주변 생물의 흰점바이러스 보유율 및 두토막눈썹참갯지렁이의 대하 Fenneropenaeus chinensis에 대한 흰점바이러스 전달 효과 (Prevalence of White Spot Syndrome Virus (WSSV) in Marine Organisms around the Shrimp Farm and Polychaete Worm-Mediated Transmission of WSSV to Fenneropenaeus chinensis)

  • 김근식;박상용;이일로;남윤권;방인철
    • 한국어병학회지
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    • 제22권1호
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    • pp.15-21
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    • 2009
  • White spot syndrome virus (WSSV) is a strong causative agent for high mortality in cultured and wild shrimps. From this study, the WSSV prevalence in marine organisms around shrimp farm as well as live feed-mediated transmission of WSSV to farmed shrimps were investigated. Based on nested-PCR method, WSSV was detected in wide array of marine organisms including Perinereis aibuhitensis (81.3% of prevalence rate, 13/16), Enedrias fangi (100%, 16/16), Ruditapes philippinarum (20%, 2/10), crab larvae (100%, 10/10), copepoda (30%, 3/10), Periophthalmus modestus (50%, 5/10), Pachygrapsus crassipes (10%, 1/10), Helice tridens (20%, 2/10) and Neomysis sp. (70%, 7/10). On the other hand, WSSV was not detected in Bullacta exarata, Uca arcuata, and Reishia clavigera. The percent prevalence of WSSV in wild shrimps, Fenneropenaeus chinensis was only 6%, but markedly increased up to 56% after a feeding trial using polychaete worms for one month, indicating that the live feed is one of significant carriers of WSSV to shrimps under practical farming conditions.