• Title/Summary/Keyword: Black Spot

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Alternaria Leaf Spot Caused by Alternaria mali on Black Chokeberry in Korea (Alternaria mali에 의한 아로니아 점무늬낙엽병)

  • Hahm, Soo-Sang;Kwon, Mi-Kyung;Kim, Byung-Ryun;Han, Kwang-Seop;Nam, Yun-Gyu
    • Research in Plant Disease
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    • v.22 no.1
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    • pp.50-54
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    • 2016
  • In early June 2014, leaf spot symptoms were observed on black chokeberry (Aronia melanocarpa) in Yesan-gun and Geumsan-gun, Chungcheongnam-do in Korea. The initial symptoms on leave surfaces were brown small-circular spots with a yellow halo lesion, and gradually the small spots were fused, all of infected leaves dropped eventually. A fungus were isolated from the initial lesion, and cultured on potato dextrose agar. Colony color on upper surface of plate varied from olive gray to charcoal gray. Size of conidia mostly extend to $19-50{\times}5-9{\mu}m$ in nature and $20-59{\times}8-13{\mu}m$ in culture, with 3-8 transverse septa and usually no longitudinal septum or only 1 longitudinal septum in 1-3 of the transverse compartments, and also have a short or long beak. Pathogenicity was investigated using wounded or unwounded black chokeberry and apple leaves. After 7 days of inoculation, leaf spots were similar to the symptoms naturally occurred in the field. On the basis of mycological characteristics, pathogenicity, and ITS rDNA sequence analysis, this fungus was identified as Alternaria mali. This is the first report of Alternaria leaf spot on black chokeberry caused by A. mali in Korea.

The classification of ballpoint pen inks in Questioned Documents by using VSC and SERRS

  • Kim, Nam Yee;Park, Sung Woo;Doble, Philip;Roux, Claude
    • Analytical Science and Technology
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    • v.17 no.4
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    • pp.315-321
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    • 2004
  • The aim of this study was to investigate the evidential value of blue and black ballpoint pens on paper by nondestructive techniques. In this work, 21 blue and 22 black ballpoint pens which were purchased on different brands were analyzed by Raman Spectroscopy and Video Spectral Comparator (VSC). Surface-Enhanced Resonance Raman Spectroscopy (SERRS) with excitation at 685 nm and VSC with several spot light filters were used for the discrimination of ballpoint pen inks. In the SERR spectra, the ballpoint pen inks on paper could be shown sharp spectral bands and distinguished by their band shapes and relative intensities. In the blue and black ballpoint pen inks, the discriminating powers (DP) by SERRS were 0.85 and 0.67 and the DP by VSC were 0.88 and 0.90, respectively. The DP by combined sequence of techniques was all 0.97 in both black and blue ballpoint pen inks.

Morphological Study of the Genus Chromis from Korea - I. External Morphology of Three Damselfishes of the Genus Chromis(Teleostei: Pomacentridae) from the Korean Waters (한국산 자리돔속 어류의 형태학적 연구 - I. 한국산 자리돔속 어류 3종, 자리돔 Chromis notata, 노랑자리돔 C. analis, 연무자리돔 C. fumea의 외부형태학적 연구)

  • Kim, Yong-Uk;Kim, Jin-Koo
    • Korean Journal of Ichthyology
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    • v.8 no.2
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    • pp.23-32
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    • 1996
  • External morphology of three species of damselfishes, Chromis notata, C. analis and C. fumea were studied based on the samples collected from the Korean waters from 1993 to 1994. In morphology of the black spot at base of pectoral fins, C. notata has a large triangluar spot at Cheju population and a small circular spot at Sin - am. In the length of pelvic fin, C. notata of Korea can be classified into 3 groups. First group has a pelvic fin that extends to the origin of anal fin, second extends to the anus, third not extend to the anus. C. analis has higher body depth than C. notata and C. fumea in % of standard length. C. fumea has a minute serrate preopercle and no black spot at base of pectoral fins. In distribution, C. notata has a more widly distriubtion area than C. analis and C. fumea. Therefore, C. notata has more tolerance of cold waters than C. analis and C. fumea.

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Different Structural Modifications Associated with Development of Ginseng Root Rot Caused by Cylindrocarpon destructans

  • Kim, Jeong-Ho;Kim, Sang-Gyu;Kim, Mi-Sook;Jeon, Yong-Ho;Cho, Dae-Hui;Kim, Young-Ho
    • The Plant Pathology Journal
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    • v.25 no.1
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    • pp.1-5
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    • 2009
  • Root rot caused by Cylindrocarpon destructans is one of the most important diseases of ginseng (Panax ginseng C. A. Meyer). Two types of symptoms found in ginseng root rot are black root rot and rusty root (rusty spots), in which disease severities are high and low, respectively. Symptom development and related histopathological changes were examined in an inoculation test on 2-year-old ginseng roots using virulent (Cy9801) and avirulent (Cy0001) isolates of C. destructans under different temperature conditions (13, 18, 23, and $28^{\circ}C$). Black root rot was only induced by Cy9801 in the lower temperature range (13, 18, and $23^{\circ}C$) and not at the higher temperature ($28^{\circ}C$). No black root rot, but only rusty spot symptoms, were induced by Cy0001 at all temperatures tested except $13^{\circ}C$, at which no symptoms occurred on over half of inoculation sites, suggesting disease development was influenced by pathogen virulence and temperature. Wound periderms were formed in all root tissues with rust spot symptoms at $28^{\circ}C$ caused by Cy9801 and at 18, 23, and $28^{\circ}C$ temperatures caused by Cy0001. No wound periderm was formed at $13^{\circ}C$ by either Cy9801 or Cy0001. Light microscopy revealed that the wound periderm was formed by initial cell divisions in cell wall formation and/or additional cell wall layering in parenchyma cells without obvious nuclear division, followed by layering of the divided cells adjacent to the inoculation sites, blocking the spread of the rot. These results suggest that disease development declined at lower temperatures and by the formation of a wound periderm at higher temperatures, and that ginseng rusty root may develop under conditions unfavorable for further disease development of C. destructans.

Altered Cultivar Resistance of Kimchi Cabbage Seedlings Mediated by Salicylic Acid, Jasmonic Acid and Ethylene

  • Lee, Young Hee;Kim, Sang Hee;Yun, Byung-Wook;Hong, Jeum Kyu
    • The Plant Pathology Journal
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    • v.30 no.3
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    • pp.323-329
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    • 2014
  • Two cultivars Buram-3-ho (susceptible) and CR-Hagwang (moderate resistant) of kimchi cabbage seedlings showed differential defense responses to anthracnose (Colletotrichum higginsianum), black spot (Alternaria brassicicola) and black rot (Xanthomonas campestris pv. campestris, Xcc) diseases in our previous study. Defense-related hormones salicylic acid (SA), jasmonic acid (JA) and ethylene led to different transcriptional regulation of pathogenesis-related (PR) gene expression in both cultivars. In this study, exogenous application of SA suppressed basal defenses to C. higginsianum in the 1st leaves of the susceptible cultivar and cultivar resistance of the 2nd leaves of the resistant cultivar. SA also enhanced susceptibility of the susceptible cultivar to A. brassicicola. By contrast, SA elevated disease resistance to Xcc in the resistant cultivar, but not in the susceptible cultivar. Methyl jasmonate (MJ) treatment did not affect the disease resistance to C. higginsianum and Xcc in either cultivar, but it compromised the disease resistance to A. brassicicola in the resistant cultivar. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC) ethylene precursor did not change resistance of the either cultivar to C. higginsianum and Xcc. Effect of ACC pretreatment on the resistance to A. brassicicola was not distinguished between susceptible and resistant cultivars, because cultivar resistance of the resistant cultivar was lost by prolonged moist dark conditions. Taken together, exogenously applied SA, JA and ethylene altered defense signaling crosstalk to three diseases of anthracnose, black spot and black rot in a cultivar-dependent manner.

Black Hair Follicular Dysplasia in a Shih-tzu Dog (시츄견에서 발생한 검은색털 모낭 이형성증)

  • Kim, Ha-Jung;Park, Hee-Myung
    • Journal of Veterinary Clinics
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    • v.32 no.6
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    • pp.527-529
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    • 2015
  • A 7 year-old intact female black spotted and white hair Shih-tzu dog visited for screening of vital condition and was suspected multifocal alopecia on physical examination. On dermatologic examination, alopecia with patches on black spot area, generalized seborrhea sicca, and bacterial infection were detected. Additionally, melanin clumping in the hair shafts on the alopecic area was detected by microscopic examination. Based on the signalment and dermatologic examination, black hair follicular dysplasia was diagnosed. To our best knowledge, this the first case report of black hair follicular dysplasia in Shih-tzu.

Leaf Spot of Cymbidium hybrida Caused by Fusarium proliferatum (Fusarium proliferatum에 의한 심비디움 저무늬병)

  • Chang, Mee;Hyun, Ik-Hwa;Lee, Young-Hee;Lee, Du-Hyung
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.664-667
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    • 1998
  • Leaf spot of Cymbidium hybrida caused by Fusarium sp. was observed at major cultivating areas including Seosan and Cheonan of Korea from 1996 to 1998. The major symptoms of the disease were small brown to black spots, 1∼2 mm I diameter, with yellow halo. Based on the mycological characteristics, Fusarium sp. isolated from the lesions was identified as Fusarium proliferatum. Macroconidia were slender, falcate to almost straight, usually 3 to 5 septate and thin walled. Microconidia were formed in chains from polyphialides, clavate or oval, usually 1-celled with flattened base. Chlamydospores were absent. The fungus showed pathogenicity to Cymbidium hybrida.

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Investigation of soybean sprout rot and the elimination of improper seeds for quality control on soybean seedlots

  • Lee, Jung Han;Kwak, Youn-Sig
    • Journal of agriculture & life science
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    • v.50 no.1
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    • pp.57-64
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    • 2016
  • Soybean sprouts have been a considered a nutrient-rich vegetable for hundreds of years. To evaluate the seedlot quality of soybean sprouts grown, and to evaluate a method for reducing the presence of improper seeds in soybean seedlots, microbes associated with soybean sprout rot were isolated from samples collected. Morphological characteristics and gas chromatography profiles of the cultured fungal and bacterial strains were identified. Eight types of improper seeds were identified: purple stain(Ps), black rot(Br), seed coat black spot(Cb), wrinkled seed(Ws), brown hilum(Bh), seed coat fracture(Cf), unripe seed(Us), and brown seed coat(Bc). The improper seeds were also dipped into 15%, 20%, and 25% NaCl solutions, as well as a saturated solution of NaCl, for 1min. As the NaCl concentration increased, the number of floating improper seeds increased as well. The highest floating rates were observed for the Cf seeds.

Disease Resistance-Based Management of Alternaria Black Spot in Cruciferous Crops (병 저항성 기반 십자화과 작물의 검은무늬병 관리)

  • Young Hee Lee;Su Min Kim;Seoung Bin Lee;Sang Hee Kim;Byung-Wook Yun;Jeum Kyu Hong
    • Research in Plant Disease
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    • v.29 no.4
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    • pp.363-376
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    • 2023
  • Alternaria black spots or blights in cruciferous crops have been devastating diseases worldwide and led to economic losses in broccoli, Chinese cabbage, kale, radish, rapeseed, etc. These diseases are caused by different Alternaria spp., including A. brassicae, A. brassicicola and A. raphani transmitted from infected seeds or insect vectors. Efforts to excavate disease resistance traits of cruciferous crops against Alternaria black spots or blights have been demonstrated. Genetic resource of disease resistance was investigated in the wild relatives of cruciferous crops, and different cultivars were screened under different inoculation conditions. Development of the disease-resistant lines against Alternaria black spots or blights was also tried via genetic transformation of the cruciferous crops using diverse plant defence-associated genes. Plant immunity activated by pre-treatment with chemicals, i. e. β-amino-n-butyric acid and melatonin, was suggested for reducing Alternaria black spots or blights in cruciferous crops. The disease resistance traits have also been evaluated in model plant Arabidopsis originating from different habitats. Various plant immunity-related mutants showing different disease responses from wild-type Arabidopsis provided valuable information for managing Alternaria black spots or blights in cruciferous crops. In particular, redox regulation and antioxidant responses altered in the Alternaria-infected mutants were discussed in this review.

Analysis of the Response Time of a Photoelectric Spot-Type Smoke Detector Depending on the Type of Fires (화원에 따른 광전식 연기감지기 반응시간 분석)

  • Jee, Seung-Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.5
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    • pp.89-94
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    • 2013
  • The fire testing performed for smoke detector model approval in Korea tests only one kind of fire smoke. A photoelectric spot-type smoke detector using Mie scattering is affected by the wavelength of light beam and the particle diameter. According to UL (Underwriters Laboratories Inc.) 268 standard, this paper analyze the characteristic of the response for a photoelectric spot-type smoke detector on sale in Korea using various fire smokes. Probability that the response time is included in non-defective range is 100% in paper fire, 90% in wood fire and 75% in flammable liquid fire, 90% in wood fire and 75% in flammable liquid fire. According to the estimation for population mean of the response time choosing a confidence level of 99%, a maximum of 19% for wood fire and that of 38% for flammable liquid fire are defective. As the result of analysis of smoke particle, this paper is found that these results are caused by the smoke particles are wide variations in size or have very black.