• The Plant Pathology Journal
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• v.22 no.3
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• pp.255-259
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• 2006

The pathogenicity to pear trees and other experimental hosts of the Apple stem grooving virus Korean isolate (ASGV-K) carried by a fungal vector, Talaromyces flavus was examined. ASGV-harboring T. flavus induced mild symptoms on virus-free pears. Symptom severity was intermediate between pears showing typical PBNLS and virus-free pears. Ten cultivars of Phaseolus vulgaris showed 35%-90% infectivity by direct infiltration into leaves and roots by ASGV-harboring T. flavus. Application of fungal cultures to soils showed 0%-70% infectivity depending on the P. vulgaris cultivar. Sap extracted from ASGV-infected Chenopodium quinoa induced similar symptoms on P. vulgaris at 25 days after inoculation. Similar symptoms were also detected on P. vulgaris which were inoculated with ASGV-harboring T.flavus. When healthy P. vulgaris leaves were challenged with sap extracted from P. vulgaris leaves infected with ASGV-harboring T. flavus, typical symptoms were observed. These data suggest that T. flavus mediates the transfer of ASGV to host plants.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.167-171
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• 2005

We isolated the Cucumber green mottle mosaic virus(CGMMV) particles from watermelon leaves and designated as CGMMV-HY1 as a watermelon isolate and attempted to characterize the pathogenic isolate responsible for such an epidemic in watermelon and also to monitor dominant viral isolates in greenhouse. The watermelon plants infected with CGMMV generally showed mottle mosaic, mosaic, growth stunting, necrosis and deformed fruit. The reactions of indicator plants to CGMMV-HY1 were the local lesions on Nicotiana tabacum cv. White Burley, Nicotiana tabacum cv. Samsun, and Chenopodium amaranticola, and the mosaic symptoms only on Cucumis sativus, but the CGMMV-HY1 did not infect Nicotiana sylvesytis, Datura stramonium, Chenopodium quinoa, and Petunia hybrida. Purified virus particles were rod-shaped and about 300 nm long. The coat protein (CP) of purified CGMMV-HY1 was single band with molecular weight of about 16.5 kDa which was confirmed by western blot analysis probed with monoclonal antibody of CGMMV-HY1. The genomic and subgenomic RNAs of 6.4 kb and 0.75 kb were revealed by the electrophoresis on 1.2% formaldehydedenatured agarose gel. Viral and complementary CGMMV-specific primer sets were designed for spanning the genome using previously reported CGMMV sequences. A 464bp of CP gene of CGMMV-HY1 was amplified by RT-PCR and cloned into PGEM-T easy vector. The nucleotide sequence of CP gene of CGMMV-HY1 shared 98%, 99%, and 100% identities with that of CGMMV strains W, KOM, and KW respectively. Based on these results, we identified CGMMV-HY1 as a CGMMV isolate of watermelon, a member of Tobamovirus.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.33-37
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• 1985

A yellow stripe and bud benting disease of soybean was commonly observed on the field at Suweon area. The causal agent was identified as alfalfa mosaic virus (AMV) by indicator plant reactions, physical properties, serological test and electron microscopy. AMV produced vein clearing, top necrosis, top bent and mottling on the parts of soybean plants. Local lesions were produced on the inoculated leaves of Vigna sesquipedialis, Vicia faba and Tetragonia expansa, while Chenopodium am, anticolor, C. quinoa, Pisum satvium, Petunia hybrida and Nicotiana tabacum 'Bright yellow' were systemically infected. The thermal inactivation point was $60^{\circ}C$, dilution end point was $10^{-3}$, and longevity in vitro was 2 days at room temperature. AMV from soybean was reacted with AMV - antiserum in agar gel diffusion test. Electron microscopy of AMV from soybean exhibited bacilliform particles of 60nm in length.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.372-377
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• 2011

A virus causing mottle and stunt symptom on Zea mays was observed around Ulleng-do, Korea and identified as Cucumber mosaic virus (CMV-ZM) based upon biological, serological, and molecular characteristics. In host range studies, the CMV-ZM isolate produced local lesions on Datura stramonium, Vigna unguiculata, Cucurbita moschata, Chenopodium amaranticolor, Ch. quinoa, whereas this isolate produced systemic mosaic on Nicotiana tabacum cv. 'Xanthi-nc', Capsicum annuum, Solanum lycopersicum, Solanum melongena, Cucurbita pepo, and Z. mays. In addition, chlorotic local rings on inoculated leaves along with severe mosaic, malformation, and fern leaf symptoms on upper systemic leaves were shown in N. glutinosa plants. Complete nucleotide sequences of each genomic RNA segment was determined and compared to those of the other CMV strains. Comparison of the nucleotide sequence of 1a open reading frame (ORF) revealed approximately 89.2-92.4% sequence identity with each CMV subgroup IA and IB strain, while showing only 78% sequence identity with CMV subgroup II. Nucleotide sequence analysis of RNA2 ORFs revealed 85.3-97.6% sequence identity with subgroup I. In ORFs of RNA3, levels of nucleotide sequence identities were higher than 92-99.2% with CMV subgroup I and lower than 82% with CMV isolates of subgroup II. These results suggest that CMV-ZM isolate is more closely related to subgroup I than subgroup II and therefore, CMV-ZM isolate might be classified into as CMV subgroup I based on biological and molecular analysis.

• Research in Plant Disease
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• v.16 no.3
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• pp.232-237
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• 2010

Tomato spotted wilt virus (TSWV) was occurred on the three vegetables of egg plant (Solanum melongena), whole radish (Raphanus acanthiformis) and sugar loaf (Cichorium intybus) at Anyang area infested with TSWV. Whole radish was produced the symptoms of necrotic spots on the leaves, and necrosis and malformation on the roots by TSWV. Egg plant was induced the symptoms of typical multiple ring spots on the leaves and necrotic rings on the fruits. Sugar loaf was infected severely with the typical symptoms of ring spots on the leaves and stunt. The three isolates of TSWV could infect locally on the indicator plants of Chenopodium amaranticolor, C. quinoa and Nicotiana debney, and systemically on N. glutinosa, N. benthamiana and Datura stramonium. Two TSWV isolates from egg plant and sugar loaf were very similar in virulence. However, the virulence of TSWV from whole radish was very different as local infection on 5 Nicotiana species including N. tabacum 'Xanthi NC'.

• Research in Plant Disease
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• v.23 no.4
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• pp.379-382
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• 2017

In March 2016, an isolate of Cucumber mosaic virus (named Gyp-CMV) was isolated from the Sambungai (Gynura procumbens) showing the symptoms of mosaic and chlorosis. The isolate Gyp-CMV was characterized by disease reactions in several indicator plants, reverse transcription-polymerase chain reaction (RT-PCR), PCR-restriction fragment length polymorphism, and sequence analysis of movement protein (3a) and coat protein (CP) genes. Tobacco, tomato, pepper, ground cherry, and lambsquarters (Chenopodium quinoa and C. amaranticolor) appeared typical CMV symptoms, but zucchini and cucumber were not infected. Phylogenetic analysis of the 3a and CP gene indicated that Gyp-CMV belongs to the CMV subgroup II. Sequence identities of the Gyp-CMV 3a and CP genes showed 99.3% and 100% to that of Hnt-CMV at amino acid level. To our knowledge, this is the first report of CMV infection in Gynura procumbens.

• The Plant Pathology Journal
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• v.28 no.3
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• pp.299-305
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• 2012

Petunia hybrida is commonly used in landscapes and interiors for its attractive flower. Virus-like foliar symptoms, including a mosaic with dark green islands surrounding the veins and chlorosis on the leaf margins, were observed on a petunia plant from Icheon, Gyeonggido, Korea. Cucumber mosaic virus (CMV) was identified in the symptomatic petunia by serological testing for the presence of CMV coat protein (CP) with a direct antibody-sandwich-enzyme-linked immunosorbent assay. An agent was mechanically transmitted to indicator plant species including Chenopodium quinoa. Examination of the inoculated plant leaves by RT-PCR analysis and electron microscopy revealed the presence of specifically amplified CP products and spherical virions of approximately 28 nm in diameter, respectively, providing confirmation of a CMV infection. Analysis of CP sequences showed that CMV petunia isolate (CMVYJC) shared 82.5-100% amino acid sequence identity with CPs of representative CMV strains. Phylogenetic analysis of CPs supports that CMV-YJC is a member of CMV subgroup IA (CMV-IA) and has biological properties of CMV-IA on host species. To our knowledge, this is the first report of CMV from P. hybrida in Korea.

• Research in Plant Disease
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• v.22 no.1
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• pp.55-58
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• 2016

A Cucumber mosaic virus (named CMV-Tr1) isolated from the white clover (Trifolium repens) showing mosaic and malformation that found in a pepper field. Cucumber mosaic virus was identified through confirmation with PT-PCR, PCR-restriction fragment length polymorphism, and sequence analysis of coat protein (CP) gene. CMV-Tr1 mosaic symptom on the upper leaves of five tobacco species including Nicotiana benthamiana, Cucumis sativus, Physalis angulata, and Solanum lycopersicon. In Chenopodium quinoa and Vigna unguiculata the isolate showed local lesions in inoculated leaves. CMV-Tr1 compared with CMV-As in the sequence identity of CP gene. CMV-Tr1 showed 98.9% and 99.5% homologies at nucleotide and amino acid levels, respectively. Phylogenetic analysis of the CP gene indicated that CMV-Tr1 belongs to the CMV subgroup IB base on the CP. To our knowledge, this is the first report of CMV in T. repens in Korea.

• Korean Journal Plant Pathology
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• v.2 no.1
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• pp.48-52
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• 1986

The virus isolated from white clover, Trifolium repens showing mosaic symptom was identified as bean yellow mosaic virus (BYMV) based on the host range, physical properties, aphid transmission, serology and morphology of the virus particles. Chenopodium amaranticolor and C. quinoa produced local lesions on the inoculated leaves and chlorotic spot on the upper leaves. Broad bean and cowpea produced local lesions on the inoculated leaves and mosaic with vein necrotic symptoms on the upper leaves. French bean showed vein necrosis on the inoculated leaves, yellow mosaic on the upper leaves and bud blight. The average size of virus particles was 740nm in length. The virus was also transmitted by Myzus persicae. The thermal inactivation point of the virus isolate was $60\;to\;65^{\circ}C$, the dilution end point $10^{-3}\;-\;10^{-4}$ and the longevity in vitro was 3 days Serological tests with the virus purified from Trifolium repens were positive to BYMV antiserum.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.121-125
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• 2002

This study was conducted to determine the causal virus that naturally infected hollyhock (Althaea rosea) plant showing mild mosaic symptom in 1999. Flexuous virus particles were found in the cytoplasm of plant tissue from infected hollyhock under transmissible electron microscopy. A virus from the genus Potyvirus under the family Potyviridae was isolated and was maintained on Chenopodium quinoa for three passages. Chlorotic local legions were used to inoculate 20 species of indicator plants. The virus infected all the tested cucurbit plants, but failed to infect Nicotiana benthamiana. Based on the host range test and RT-PCR analysis, the potyvirus was identified as a strain of Zucchini yellow mosaic virus-A (ZYMV-A), one of the major pathogens of cucurbits. Infectivity analysis showed that ZYMV-A induced faster systemic symptom than ZYMV-Cu on squash and other cucurbit plants, suggesting that ZYMV-A was a more severe strain. To better characterize ZYMV-A, Western blot assay was carried rout to the coat protein (CP) of the virus using ZYMV-specific antiserum with ZYMV-Cu and other potyviruses. The CP of the virus reacted strongly with the antiserum against ZYMV, and other tested antisera did not react with the CP of ZYMV-A. Results strongly suggest that the potyvirus infecting hollyhock was a novel strain of ZYMV. This is the first report on ZYMV as the causal virus infecting hollyhock in Korea.