• 제목/요약/키워드: leaf spots

검색결과 222건 처리시간 0.018초

파를 가해하는 파굴파리의 충태별 피해 양상 및 행동 (Injury Aspects of the Stone Leek Leafminer, Liriomyza chinensis Kato (Diptera: Agromyzidae) on Welsh Onion)

  • 최인후;김정화;김길하;김철우
    • 한국응용곤충학회지
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    • 제42권4호
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    • pp.335-343
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    • 2003
  • 파굴파리의 파 잎의 가해 습성을 조사한 결과 암컷성충은 잎의 외부에서 즙액을 섭취하고 엽육에 산란함으로서 피해를 주었다. 피해 잎은 직경 0.48mm의 백색 원형의 흡즙흔이 수십 개씩 점선을 형성하였고, 산란흔은 0.1${\times}$0.14mm 장타원형이고 1개 또는 수 개씩 V자형으로 무리를 지어 산란하였다 집단사육에서 성충의 흡즙은 우화당일에 시작하여 4-5일째에 가장 왕성하였고, 산란은 우화 2일부터 6일째까지 일별 산란수가 비슷하였다. 또한 흡즙과 산란은 밤보다는 낮에 더 활발하였다. 유충은 엽육에 갱도를 뚫고 엽의 위아래로 섭식하다가 밀도가 높고 발육이 진전되면 잎 끝쪽에서부터 아래쪽으로 이동하면서 잎을 고사시켰다. 유충 1마리의 식해량은 72.1$\textrm{mm}^2$이었다. 노숙유충이 잎에서 탈출하는 시간은 오전 5-7시이었고, 번데기는 토양깊이 5cm, 파측면 10 cm근처에서 대부분 용화하였다. 월동태는 번데기로 지표에서 토양깊이 10cm 이내에서 서식하였으며, 5월상순부터 6월하순까지 약 2개월 사이에 우화하였다. 성충은 잔존된 파, 묘상, 이식된 포장, 밭뚝 등으로 이동하여 생존하였다.

Characteristics of Tobacco Mosaic Virus Isolated from Wasabi (Eutrema wasabi) in Korea

  • Kim, Hyung-Moo;Lee, Kui-Jae
    • The Plant Pathology Journal
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    • 제15권4호
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    • pp.247-250
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    • 1999
  • Wasabies showing mosaic symptoms were collected and extracted for virus purification. Tobacco mosaic virus (TMV) was identified as causal agent by electron microscopy and nucleic acid and coat protein analyses. TMV strains were determined by enzyme-linked immunosorbent assay (ELISA). TMV was identified as W and C strain in wasabi. The results of host reaction indicated that this virus induced local lesions on Nicotiana tabacum cv. Bright Yellow and N. glutinosa, leaf spots on Chenopodium amaranticolor and mosaic symptoms on wasabi. Rot shape virus particles were observed and was about 300 nm in length. About 6.5 kb single RNA molecule was observed from extracted viral RNA sample and 26 KDa coat protein was detected in denatured acrylamide gel. Infection ratio of TMV was 8% for the first cultivation year, but was 22% for the second year when TMV-W antiserum was used. The results of this experiment showed that infection ratios of both TMV-W and TMV-C strains were higher compared to that of TMV-P strain.

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A Novel Alternaria Species Isolated from Peucedanum japonicum in Korea

  • Deng, Jian Xin;Cho, Hye Sun;Paul, Narayan Chandra;Lee, Hyang Burm;Yu, Seung Hun
    • Mycobiology
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    • 제42권1호
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    • pp.12-16
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    • 2014
  • We isolated and examined a new Alternaria sp., which causes leaf spots on Peucedanum japonicum in Korea, by using molecular and morphological methods. Phylogenetic analysis based on a combined internal transcribed spacer region analysis and two protein-coding genes (gpd and Alt a1) demonstrated that the causal fungus was most closely related to A. cinerariae and A. sonchi, and relevant to A. brassicae. However, conidial morphology indicated that it is a novel species within the genus Alternaria, and therefore we have assigned the fungus a new name in this study.

Detection of Rice Disease Using Bayes' Classifier and Minimum Distance Classifier

  • Sharma, Vikas;Mir, Aftab Ahmad;Sarwr, Abid
    • Journal of Multimedia Information System
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    • 제7권1호
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    • pp.17-24
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    • 2020
  • Rice (Oryza Sativa) is an important source of food for the people of our country, even though of world also .It is also considered as the staple food of our country and we know agriculture is the main source country's economy, hence the crop of Rice plays a vital role over it. For increasing the growth and production of rice crop, ground-breaking technique for the detection of any type of disease occurring in rice can be detected and categorization of rice crop diseases has been proposed in this paper. In this research paper, we perform comparison between two classifiers namely MDC and Bayes' classifiers Survey over different digital image processing techniques has been done for the detection of disease in rice crops. The proposed technique involves the samples of 200 digital images of diseased rice leaf images of five different types of rice crop diseases. The overall accuracy that we achieved by using Bayes' Classifiers and MDC are 69.358 percent and 81.06 percent respectively.

First Report of Sclerotinia Rot Caused by Sclerotinia sclerotiorum on Some Vegetable Crops in Korea

  • Chang, Seog-Won;Kim, Sung-Kee
    • The Plant Pathology Journal
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    • 제19권2호
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    • pp.79-84
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    • 2003
  • Sclerotinia rot occurred severely on some vegetable crops grown in Namyangju, Yangpyung, and Yangiu areas in Korea in 2001-2002. The crops infected with Scterotinia sp. were Adenophora remotiflora, Armoracia lapathfolia, Angelica acutiloba, Angelica archangelica, Anthriscus sylvestris, Aster tataricus, Beta vulgaris var. cicla, Brassica campestris var. marinosa, Brassica juncea var. laciniata, Chicholium intybus, Lactuca indica var. dracoglossa, Lactuca sativa var. oak-leaf, Petroselinum crispum, and Phyteuma japonicum. The fungus associated with the disease was identified as Sclerotinia sclerotiorum, based on the morphological characteristics of the pathogen. The symptoms were water-soaked spots that enlarged later and became a watery soft rot. Infected parts became yellow and then turned brown, followed by death of the whole plant. White mycelia developed on the upper petioles and leaves and on the soil where these plant parts lay. Then black sclerotia in variable size and shape formed from the mycelial mass. Pathogenicity of the fungus was proven by artificially inoculating each crop. This is the first report of Sclerotinia rot on the listed vegetable crops in Korea.

참깨 종자전염진균(種子傳染眞菌)의 검정(檢定) 및 Corynespora cassicola의 병원성(病原性) (Detecting Seed-borne Fungi of Sesame and Virulance of Corynespora cassicola)

  • 유승헌;박종성
    • 농업과학연구
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    • 제6권1호
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    • pp.27-32
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    • 1979
  • 충남농촌진흥원으로부터 분양받은 참깨종자의 종자전염진균을 표준 Blotter 법으로 조사하였던 바 12종의 균류가 검출되었다. 그 중 Alternaria sesamicola, A. tenuis, Corynespora cassicola가 많은 비율로 검출되었다. Chlorine으로 종자처리를 하였을 경우, C. cassicola를 제외한 모든 균이 거의 완전히 제거되었다. 참깨 종자내의 감염부위는 C. cassicola가 가장 깊숙이 배에까지 감염되어 있었다. C. cassicola의 병원성을 조사하였던 결과 참깨의 잎과 줄기에 심한 반점을 형성하고 병반이 급격히 확대되며 말라죽었다.

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New Rust Disease of Korean Willow (Salix koreensis) Caused by Melampsora yezoensis, Unrecorded Pathogen in Korea

  • Yun, Yeo Hong;Ahn, Geum Ran;Yoon, Seong Kwon;Kim, Hoo Hyun;Son, Seung Yeol;Kim, Seong Hwan
    • Mycobiology
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    • 제44권4호
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    • pp.335-337
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    • 2016
  • During the growing season of 2015, leaf specimens with yellow rust spots were collected from Salix koreensis Andersson, known as Korean willow, in riverine areas in Cheonan, Korea. The fungus on S. koreensis was identified as the rust species, Melampsora yezoensis, based on the morphology of urediniospores observed by light and scanning electron microscopy, and the molecular properties of the internal transcribed spacer rDNA region. Pathogenicity tests confirmed that the urediniospores are the causal agent of the rust symptoms on the leaves and young stems of S. koreensis. Here, we report a new rust disease of S. koreensis caused by the rust fungus, M. yezoensis, a previously unrecorded rust pathogen in Korea.

Occurrence of Apple scar viroid-Korean strain (ASSVd-K) in Apples Cultivated in Korea

  • Lee, Ju-Hee;Park, Jean-Kyung;Lee, Dong-Hyuk;Uhm, Jae-Youl;Ghim, Sa-Youl;Lee, Jai-Youl
    • The Plant Pathology Journal
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    • 제17권5호
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    • pp.300-304
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    • 2001
  • Apple is the most economically important fruit in Korea. The suspected viroid disease of dapple apple was found in apple fruits cultivated in Kyungpook province. Symptoms begin in mid-July as small circular spots, which stand out against the background color on the young fruit. Dappling of the fruit becomes more intense and easier to detect as the fruit approaches maturity; the affected spots remain yellowish as the fruit matures. no leaf or bark syndromes have been associated with this disease. The infected fruits are downgraded considerably during quality grading. The low molecular weight RNA containing viroid RNA molecules were extracted from the peels of the apples with dapple symptoms. The RNA molecules were extracted from the apples using Qiagen column chromatography. The purified RNAs were used for the synthesis of cDNA with RT-PCR. The PCR products were then ligated into a pGEM-T Easy vector, cloned and sequenced. The sequence of the viroid RNA molecule shows 331 nucleotides with one base difference ("G" insertion between the position of 133 and 134) compared with that of the Apple scar skin viroid (ASSVd) reported by Hashimoto and Koganezawa in Japan. This is the first report on the occurrence of the ASSVd in apple trees cultivated in Korea, as well as the identification of a new Korean strain of the ASSVd.the ASSVd.

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Acidovorax avenae subsp. cattleyae에 의한 팔레놉시스 세균성갈색점무늬병의 발생 (Incidence of Bacterial Brown Spot of Phalenopsis Orchids Caused by Acidovorax avenae subsp. cattleyae)

  • 한경숙;이승돈;박종한;한유경;김대현;이중섭
    • 식물병연구
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    • 제15권3호
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    • pp.183-186
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    • 2009
  • 팔레놉시스 주요 재배지역인 경기, 부산에서 잎에 점무늬를 형성하며 병반의 가장자리는 선명한 노란색을 띄며, 잎 뒷면을 햇빛에 비춰볼 때 수침상을 나타내었고 병징이 심해지면 수침상 점무늬 병반이 합쳐지면서 잎 전체가 짙은 갈색으로 말라죽었다. 팔레놉시스 잎의 병반부로부터 세균을 분리하여 생리생화학적 방법, 병원성 시험결과 Acidovorax avenae subsp. cattleyae로 동정하였으며 이 병을 팔레놉시스 세균성갈색점무늬병으로 명명하였다.