• Title/Summary/Keyword: leaf spots

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Nested PCR Detection of Pseudomonas syringae pv. actinidiae, the Causal Bacterium (Nested PCR을 통한 참다래 궤양병균 (Pseudomonas syringae pv. actinidiae)의 검출)

  • Jung, Jae-Sung;Han, Hyo-Shim;Jo, Youn-Seob;Koh, Young-Jin
    • Research in Plant Disease
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    • v.9 no.3
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    • pp.116-120
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    • 2003
  • A PCR method that combines biological and enzymatic amplification of PCR targets was developed for the detection of Pseudomonas syringae pv. actinidiae on kiwifruit leaves. A nested PCR was performed with primers designes from the coding sequence of the cfl gene, which is involved in production of the phytotoxin coronatine. The first and second primer sets efficiently amplified expected 665 and 310-bp fragments, respectively. With two successive amplifications, as few as 20 CFU/ml of P. syringae pv. actinidiae could be detected on ethidium bromide-stained agarose gel. Leaf samples were collected from 4 kiwifruit trees showing yellow halo spots on leaves and incubated in pepton-sucrose broth for 12 h at $16^{\circ}$C before PCR amplification. Positive detection was obtained with one sample, which was proved as a diseased plant in the next spring.

Rust of safflower (Carthamus thinctorius) caused by Puccinia carthammi (Puccinia carthami에 의한 잇꽃 녹병)

  • Park, Kyeng-Seuk;Lee, Soon-Gu
    • Research in Plant Disease
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    • v.9 no.3
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    • pp.128-130
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    • 2003
  • Rust diseases were found on safflower (Carthamus thinctorius) fields located in Euisong-gun Gyengbuk province in Korea. The infection rate of the disease in surveyed area was about 15% in 2001. The typical symptoms of the disease appeared first as small white spots on the leaf and turn brownish, dark brown spores revealed on them. Uredospores were light brown in color, ellipsoid or spherical in shape and 21~23 ${\times}$ 21~25${\mu}m$ in size. Teliospores were chestnut-brown in color, ellipsoid or ovoid in shape and 35~40 ${\times}$ 27~33${\mu}m$ in size. Pedicels were non-color of limpidness in color and 15~30${\mu}m$ in size. The causal fungus was identified as Puccinia carthami, based on morphological charateristics. This is first report on the rust of safflower caused by Puccinia carthami in Korea.

Cultural Characteristics of Chromogenic and Teleomorphic Strains of Collectotricum gloeosporioides Isolated from Apple and Red pepper (사과와 고추에서 분리한 Colletotrichum gloeosporioides의 색소형성형 및 유성세대형 계통의 배양적 특징)

  • Lee, Du-Hyung
    • The Korean Journal of Mycology
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    • v.25 no.4 s.83
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    • pp.340-347
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    • 1997
  • Conidia and cultural characteristics of isolates of chromogenic and teleomorphic strains of Colletotrichum gloeosporioides from apple and red pepper were compared. The mycelial growth of teleomorphic strains was faster than that of chromogenic strains in potato dextrose agar and V-8 agar. The chromogenic isolates from apple and red pepper developed. white gray to gray green mycelial rings interspersed with salmon to apricot colored conidial masses in colonies on potato dextrose agar and V-8 agar and none formed on ascigerous stage in cultures. The chromogenic isolates from red pepper produced conidia, most with one apex attenuated on apple and potato dextrose agar whereas fusiform and smaller conidia were produced in V-8 agar and water agar leaf medium. The chromogenic isolates from apple produced fusiform conidia in the media tested. The teleomorphic isolates from apple and red pepper produced cylindrical conidia, most with both apices rounded, developed white gray to dark olive green in a zonate pattern with small dark spots throughout colonies and formed the ascigerous stage in cultures.

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Characteristics of a NP Strain for Cucumber mosaic virus(CMV-NP) Identified Newly from Sweet Pepper Showing Fruit Necrosis (과일 괴저 병징의 단 고추에서 분류동정한 오이모자이크바이러스의 새로운 계통 CMV-NP 특성)

  • Cho, Jeom-Deog;Kim, Jeong-Soo;Lee, Joong-Hwan;Chung, Bong-Nam
    • Research in Plant Disease
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    • v.14 no.2
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    • pp.134-137
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    • 2008
  • A strain of Cucumber mosaic virus(CMV) was isolated newly from sweet pepper(Capsicum annuum var. angulosum) showing necrosis with large necrotic spots on fruits and vein banding with malformation on leaf at Cheongdo area in Gyeongsangbukdo. The new strain was designated as a CMV-NP and the shape of virus particles was isometric of 26 nm in diameter from the sweet pepper fruit by Dip method. The strain of CMV-NP was identified genetically by VC/RT-PCR. CMV-NP could infect systemically on the 9 indicator plants including Cucumis sativus, but it could infect locally on Chenopodim amaranticolor and C. quinoa. CMV-NP induced the specific symptoms of necrotic rings on the inoculated and the upper leaves of N. rustica and Tetragonia expansa. On Cucumis sativus, the large chlorotic ring and vein chlorosis were produced on the upper leaves. CMV-NP had no virulence on Datura stramonium.

Halo Blight of Kudzu Vine Caused by Pseudomonas syringae pv. phaseolicola in Korea

  • Jeon, Yong-Ho;Chang, Sung-Pae;Kim, Sang-Gyu;Kim, Young-Ho
    • The Plant Pathology Journal
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    • v.22 no.2
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    • pp.119-124
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    • 2006
  • Kudzu vine(Pueraria montana var. lobata) is an invasive climbing woody vine that envelops trees and shrubs, pressing physically and shutting out sunlight, which needs to be controlled. Kudzu vine pathogens were surveyed as a way to seek its biocontrol agents in 2002. Occurrence of a bacterial halo blight disease of kudzu vine was observed at several localities in Korea including Euiwang and Suwon in Gyeonggi Province, Daejon, and Gochang and Buan in Jeonbuk Province. Symptoms of brown to black spots with a surrounding yellowish halo appeared from June and lasted till the rainy season without much expansion, but accompanying often leaf blight and defoliation. Isolated bacteria were identified as Pseudomonas syringae pv. phaseolicola based on physiological and cultural characteristics, Biolog, fatty acid and 16S rDNA sequencing analyses. In artificial inoculation test, these bacteria produced the same halo spot symptoms on kudzu vine and bean plants. They also induced hypersensitive responses (HR) on tobacco, tomato, and chili pepper leaves. This is the first report of a bacterial disease of kudzu vine in Korea, and the bacterial pathogen can be used as a biocontrol agent against the pest plant.

First Report of Rust Disease Caused by Puccinia phragmitis on Rumex japonicus in Korea (Puccinia phragmitis에 의한 참소리쟁이 잎녹병 발생 보고)

  • Lee, Seung-Yeol;Park, Ji-Won;Kang, In-Kyu;Jung, Hee-Young
    • Research in Plant Disease
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    • v.26 no.1
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    • pp.53-56
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    • 2020
  • Red spots symptoms were observed on the leaves of Rumex japonicus Houtt. in Goesan, Korea, in May 2019. Diseased leaf showing red spot and white-colored sori were found behind of diseased leaves. Aeciospores were confirmed and observed using a stereomicroscope, light microscope, and scanning electron microscope. They were globose or ovoid and measured 19.0-24.4×19.0-24.5 ㎛, with verrucae ornamentation. For the phylogenetic analysis, partial of large subunit rDNA region and cytochrome c oxidase subunit III were sequenced. As a result, the isolated fungus species showed high similarities with Puccinia prizeliana. Based on the previous report, morphological characters, phylogenetic analysis, it was confirmed as Puccinia phragmitis which have not been reported in Korea, and we firstly report this fungal agent on R. japonicus as P. phragmitis in Korea.

Characterization of Melon necrotic spot virus Isolated from Muskmelon

  • Park, Gug-Seoun;Kim, Jae-Hyun;Kim, Jeong-Soo
    • The Plant Pathology Journal
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    • v.19 no.2
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    • pp.123-127
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    • 2003
  • A severe disease of muskmelon (Cucumis melo cv. Alsnight) grown on rockwool in a plastic house was characterized by leaf and stem necrosis followed by death of the plants. In 2001, an isolate of Melon necrotic spot virus-MN (MNSV-MN) of the genus Camovirus was identified as the causal agent of the disease on the basis of biological reactions and nucleotide sequence analyses of coat protein (CP) gene. MNSV-MN induced necrotic local lesions on mechanically inoculated leaves and systemic necrotic spots on the upper leaves of melon cvs. Alsnight, Rui III, Party, Imperial, and Seolhang. However, the inoculated leaves of watermelon and cucumber showed only necrotic lesions. DsRNAs extracted from the melon infected with MNSV-MN were separated into three components. Molecular sizes of the dsRNAs were estimated at approximately 4.5, 1.8, and 1.6 kbp. The amplified cDNA products of CP gene for MNSV-MN by RT-PCR showed approximately 1.2 kbp. The amplified DNA was digested to three fragments by MspI treatment. The cDNA of the genomic RNA of MNSV-MN was cloned and the region deduced to encode the CP was sequenced. The CP coding region, located near 3' end of the genome, consisted of 1,170 nucleotides and had the potential to encode a 390 amino acid protein. The nucleotide and amino acid sequences of MNSV-MN CP gene were 84.0-94.6% and 90.8-94.9% identical with other MNSV isolates found in the GeneBank database, respectively. This is the first report on the occurrence of MNSV in Korea.

A Study on Identification Keys of Araliae Continentalis Radix and its Adulterants : Focused on External·Internal Morphology and Pattern Analysis (독활(獨活)과 그 위품의 감별기준 연구 : 외·내부형태 및 이화학패턴을 중심으로)

  • Yoon, Jee-Hyun;Ju, Young-Sung
    • The Korea Journal of Herbology
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    • v.33 no.2
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    • pp.29-43
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    • 2018
  • Objectives : Araliae Continentalis Radix(AC) is a medicinal herb belonging to the drug efficacy group treating musculoskeletal disorders(MSD) with anti-inflammatory, analgesic and antipyretic action. However, due to morphologic and onomastic similarity, adulterants(Angelicae Pubescentis Radix: AP, Gypsophilae Oldhamianae Radix: GO, Levistici Officinalis Radix: LO) have been included or replaced the standard. Methods : Multilateral methods were carried out on the identification of AC and its adulterants. Macroscopic and microscopic characteristics were observed by using stereoscope and microscope. For the comparison of chromatogram pattern, standard compounds were analyzed simultaneously using high performance liquid chromatography. Results : 1. The macroscopic identification of original plants was determined by the phyllotaxis type, the inflorescence type, the leaf margin and the color of flowers. The macroscopic identification of herbal materials was examined by oil spots, the cambium, heteromorphic vascular bundles, and the pholem. 2. For the microscopic identification, the fact whether its xylem ray is proliferated or not was first determined. Then medicinal herbs were secondly divided by cellular inclusions, fiber bundles, the distribution of secretary canals and the shape of cambium. 3. AC and its adulterants showed different chromatographic fingerprints. AC was containing continentalic acid and kaurenoic acid. AP was containing osthole and columbianadin. LO was containing osthole and falcarindiol. None of the compounds were found in GO. Conclusions : This recent identification keys of might be helpful to discriminate the pharmacopoeia standard and its adulterants for the right usage in clinics.

A Study of the Characteristics of Painting Materials Used in Welcome Feast for the Pyeongan Governor: Focusing on Banquet at Yeongwangjeong Pavilion (평안감사향연도(平安監司饗宴圖)의 채색 재료 특성 연구 -연광정연회도(練光亭宴會圖)를 중심으로-)

  • Park, Jin Ho;Chang, Yeon Hee;Ko, Soo Rin
    • Conservation Science in Museum
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    • v.28
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    • pp.109-136
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    • 2022
  • This study analyzes the , one of the three panels of 《Welcoming Banquets for the Governor of Pyeong-an》, a documentary painting of the late Joseon Dynasty, with the aim to identify the coloring materials used in the painting. The painting was first imaged at each wavelength in order to minimize the potential problems in the process of analyzing specific parts. This study applied X-rays to identify ink, gold, and organic and inorganic pigments and used infrared rays to find ink and copper-based pigments. It also applied hyperspectral imaging to distinguish organic pigments from black, blue, and green materials. It also analyzed spots selected for each color to identify the following materials: white lead (white), ink/indigo (black), a combination of red lead and cinnabar (red), pink dye, purple dye, iron oxides (brown), orpiment/dye (yellow), malachite/malachite and yellow dye/indigo (green), azurite/white lead and indigo/indigo (blue), indigo and cochineal (violet), and gold leaf (gold). It is expected that more efficient analysis will be made possible by securing a sufficient library for each wavelength.

Defense Inducer Compounds Up-regulated the Peroxidase, Polyphenol Oxidase, and Total Phenol Activities against Spot Blotch Disease of Wheat

  • Puja Kumari;Chandrashekhar Azad;Ravi Ranjan Kumar;Jyoti Kumari;Kumar Aditya;Amarendra Kumar
    • The Plant Pathology Journal
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    • v.39 no.2
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    • pp.159-170
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    • 2023
  • Spot blotch disease of wheat caused by Bipolaris sorokiniana (Sacc.) Shoem is considered as an economically important disease which affects all the growing stages of wheat crop. Therefore, it is important to search some effective management strategies against the spot blotch pathogen. Some synthetic elicitor compounds (salicylic acid, isonicotinic acid, and chitosan) and nano-particles (silver and aluminum) were tested against the pathogen to observe the change in biochemical activity and defense action of wheat plant against spot blotch disease. All the tested elicitor compounds and nano-particles showed a significant increase in activity of peroxidase, polyphenol oxidase (PPO), and total phenol over control. The highest increase in activity of peroxidase was recorded at 72 h from chitosan at 2 mM and 96 h from silver nano-particle at 100 ppm. Maximum PPO and total phenol activity were recorded from chitosan at 2 mM and silver nano-particle at 100 ppm as compared to pathogen-treated and healthy control. The lowest percent disease index, lowest no. of spots/leaf, and no. of infected leaves/plant were found in silver nano-particle at 100 ppm and chitosan at 2 mM, respectively. The use of defense inducer compounds results in significantly up-regulated enzymatic activity and reduced spot blotch disease. Therefore, chitosan and silver nano-particle could be used as alternative methods for the management of spot blotch disease.