• 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.

• Research in Plant Disease
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• v.10 no.2
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• pp.154-158
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• 2004

To analyze the relationship between CGMMV occurrence and seed contamination by cucumber cultivars, cucumber cultivars of CGMMV infected field and diseased degree were investigated in cucumber main cultivation regions of Jeonnam province from 1999 to 2002. While the diseased degree was different by years and cultivars, CGMMV occurred for 4 years in 'Janghyeongnakhap', for 3 years in 'Jangjukcheongjang', and for 2 years in 'Gyeoulsali' and 'Gyeoulnagi'. CGMMV was detected in seeds of 'Janghyeongnakhap' and 'Jangjukcheongjang' by ELISA test, and seed of 'Jangjukcheongjang' showed positive reaction in bioassay. As a result of resistant test of 34 cultivars to CGMMV, all cultivars showed mosaic symptoms in pot test but only 'Hanboksamcheok' showed mild mosaic symptom in field test.

• Research in Plant Disease
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• v.10 no.1
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• pp.48-52
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• 2004

We investigated the effect of infection time of CGMMV on the growth and quality of watermelon and cucumber plants. The effect (damages by CGMMV) was estimated on the watermelon where CGMMV had been inoculated at different growth stages, vegetative (transplanting stage, vegetative growth stage) and reproductive growth stage (fruiting stage and fruit hypertrophy stage). In the case of cucumber, CGMMV was inoculated at transplanting stage and Erst flowering stage, respectively. When watermelon was infected with CGMMV at vegetative growth stage, vine length, internode length, leaf area, and fruit weight of the plants largely decreased compared with control plants, while the infected plant growth was not very different from control plants when it was infected at reproductive growth stage. Brix of the fruit of watermelon also decreased when the plants was infected with the virus earlier than fruiting stage. The occurrence of 'Pisubag', internal discoloration and decomposition of watermelon fruits, tended to be increased as earlier infection time with CGMMV In the case of cucumber infection time with CGMMV did not influence earlier growth of the plants, but did later growth showing that plant height, vine length, internode length, number of leaf, leaf wide, and leaf length of the plants decreased as infection time became to be earlier.

• Research in Plant Disease
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• v.10 no.1
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• pp.53-57
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• 2004

Cucumber green mottle mosaic virus (CGMMV) was a major pathogen of watermelon and had affected seriously to watermelon production in Korea. Rapid and sensitive detection method of CGMMV associated with bottle gourd (Lagenafia siceraria) seeds was developed by using RT-PCR in this study. A pair of primeri Wmfl and Wmrl, specific for CGMMV was designed from coat protein gene sequences of CGMMV-W and used for amplifying 420 bp product in RT-PCR. To simplify the virus extraction procedure and reduce an inhibitor from the extract for the RT-PCR, some methods using ethanol precipitation, double filtration, polyethylene glycol precipitation and phenol/chloroform/isoamyl alcohol extraction procedure were compared and the phenol/chloroform/isoamyl alcohol extraction procedure was selected by its enhanced sensitivity. This detection method using the selected extraction step and the primers for RT-PCR could reliably detect an infected level of one CGMMV-infested seed in 1,000 seeds. This rapid and sensitive RT-PCR assay provides auseful tool for the specific detection of CGMMV in bottle gourd seed samples containing high levels of back-ground inhibitors.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.11-17
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• 2007

Previously developed transgenic watermelon rootstocks (gongdae) inserted by CGMMV-CP were examined to test the virus tolerance levels. In the restricted plastic house, the $T_{3}$ watermelon rootstock showed tolerance to CGMMV until 70 days after inoculation on the leaves while the non-transformed watermelon rootstock became susceptible at 20 days after inoculation. In the field, tolerance efficiency of transgenic rootstocks maintained up to 40% at 71 days after contamination with CGMMV in the soil while all of the non-transformed rootstocks became susceptible at 37 days with the same condition. In the same field, transgenic rootstocks showed more tolerance to CGMMV than the non-transformed rootstocks as those were inoculated on the leaves, but it showed only 10 days delay before being susceptible. Therefore, transgenic rootstocks have a characteristic of delay effect against CGMMV susceptibility, rather than resistance character. From $T_{3}$ rootstocks homozygous for the CGMMV-CP horticulturally favorable individuals were selected for further breeding and a transgenic line was finally obtained at the $BC_{1}T_{5}$. A material transfer experiment was conducted to find out if the DNA, RNA or expressed protein in the transgenic rootstocks could move to the grafted scion (non-transformed watermelon, Super-Kumcheon). PCR, northern, and western blot analysis were performed and no evidence of transferring of those materials from rootstock to scion was ever found.

• Korean Journal of Plant Tissue Culture
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• v.25 no.6
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• pp.519-524
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• 1998

A simple and reliable method to diagnose cucumber green mottle mosaic virus of watermelon in Korea (CGMMV-WK) was determined by RT-PCR, and coat protein gene for CGMMV-WK was cloned. Comparing to a method reported by Lee et al. (1996), the method developed here showed a better RT-PCR reaction. RT-PCR was possible by one step in the PCR reaction mixture that contains 20 pmol of primer, reverse transcriptase (30 unit), RNasin (5 unit) using the crude RNA solution. RT-PCR condition for specifically diagnosing CGMMV-WK was that cDNA was synthesized at 42$^{\circ}C$ for 45 min followed by pre-denaturation at 95$^{\circ}C$ for 2 min, and then PCR reaction was carried out with a programmed condition that consisted of 36 sequential cycles at 96$^{\circ}C$ for 30 sec, 6$0^{\circ}C$ for 30 sec, and 72$^{\circ}C$ for 1 min. A gene encoding the coat protein of CGMMV-WK was cloned and characterized. Nucleotide sequence of coat protein gene of CGMMV-WK shared 98.77% and 99.38% of sequence identity with those of CGMMV-W and CGMMV-SH, respecitvely, however, all of amino acid sequences were same.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.473-477
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• 2010

Cucumber green mottle mosaic virus (CGMMV) is one of major plant viruses infecting cucurbitaceous crops via soil or infected seeds. This study investigate ecology of infection of CGMMV in soil, and control tactics of this virus with soil hygiene and crop rotation. This virus was survival to 50% in soil without host plants for 17 months and had high vitality in debris of infected plant over 1 year. Infection rate of CGMMV was 1.0~3.6% in control soil and 12~36% in soil transplanted with wounded root of watermelon. It showed that wounded root may affect severity of soil infection. Rotation between rice and watermelon caused dramatical reduction from 76.8% in repeated cultivation to 7.3% of progeny infection by CGMMV. Therefore, it is suggested that crop rotation be effective for control of CGMMV.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.243-248
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• 2001

Two Tobamoviruses, Cucumber green mottle mosaic virus (CGMMV) and Zucchini green mottle mosaic virus (ZGMMV), occurred in Korea in 463 ha in 1998, 33.9 ha in 1999, and 44.2 ha in 2000. CGMMV was detected in watermelon, cucumber, oriental melon, and melon, whereas ZGMMV was mainly detected in zucchini squash. Thirty-six CGMMV isolates wee classified into three types by analysis of single strand cDNA conformational polymorphism (SSCP) of the coat protein gene. In a comparison of serological relationships among CGMMV, ZGMMV, and Kyuri green mottle mosaic virus (KGMMV), the three tobamoviruses specifically reacted with each homologous antibody in the double-antibody sandwich enzyme-linked immunosorbent assay and rapid imunofilter paper assay (RIPA), although ZGMMV and KGMMV were slightly biologcially similar. In a survey of the three tobamoviruses in cucurbitgrowing field in Korea by RIPA, CGMMV and ZGMMV were detected but KGMMV was not found in commercially growing cucurbit crops so far. Seed contamination ratio of CGMMV in bottle gourd seeds tested was 84%, while seed trasmission ratio from the virus-contaminated seeds was 2.0%. Soil transmission ratio was 0-3.5% in fields naturally infested with CGMMV or ZGMMV. Control measures of the virus diseases are roguing and sanitation. These suggest that it is important to rogue the first infected crops, which include the seed and soil, especially early in the season. This may be practicable to control the diseases because CGMMV and ZGMMV have a narrow host range restricted to cucurbitaceous crops.

• The Plant Pathology Journal
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• v.22 no.1
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• pp.21-27
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• 2006

We immunized BALB/c mice with purified Cucumber green mottle mosaic virus isolate HY1 (CGMMV-HY1). Through the selection of positive clones that were grown on the HAT medium, four sensitive monoclonal clones (CG99-01, CG99-02, CG99-03, and CG99-04) were selected from 500 Hypoxanthine-guanine phosphoribosyltransferase positive hybridoma cells. Four sensitive clones of CGMMV-HYI were determined as IgM type of the subclass of mouse immunoglobulins Ig group. The titer of monoclonal antiserum against CGMMVHY1 was estimated 1:12,800 by the indirect ELISA. Although monoclonal antibodies (MAbs) from CG99-01 and from CG99-04 cross-reacted with Zucchini green mottle mosaic virus and Kyuri green mottle mosaic virus, MAb from the cell line CG99-03 was highly specific to CGMMV. No MAbs cross-reacted with Cucumber mosaic virus-Fny. Only CG99-04 reacted with Pepper mild mottle virus weakly and CG99-02 reacted with both CGMMV and KGMMV. CGMMV was detected from the rind of watermelon fruit by DAS-ELISA of CGMMV-HY1, but not from the flesh of watermelon. Average seed transmission rate of CGMMV in watermelon was $24\%$ from symptomatic watermelon collected from 5 regions of Gyeongnam province. CGMMV was detected by DAS-ELISA with specific MAb of CGMMVHY1 periodically from root stock, during the sequential process for nursery seedling in Haman. Necrotic spots on cotyledons of root stock seedling progressed to reveal the typical symptomatology on the primary leaves of scion upon grafting. Here, we have established MAb based ELISA system, which could accurately detect CGMMV from watermelon seeds, nursery seedlings, transplants and field samples from greenhouse or open out door field as well.

• Research in Plant Disease
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• v.15 no.2
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• pp.68-71
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• 2009

Cucumber green mottle mosaic virus (CGMMV) was not infected in figleaf gourd by sap inoculation. However CGMMV was detected by RT-PCR from the figleaf gourd collected from a field growing cucumber grafted onto figleaf gourd in Cheonan, Chungcheongnam Province in 2008. Which field showed 100% infection rate of the virus disease. In the experiment grafted with cucumber onto figleaf gourd, transportation of CGMMV through cucumber to figleaf gourd was confirmed by RT-PCR when the virus was mechanically inoculated on the leaves of the cucumber. The amplified DNA concentration of the virus on electrophoresis gel was much higher in the cucumber than in the figleaf gourd. However, the virus particles from the figleaf gourds were not observed under electron microscopy, also sap of the figleaf gourds was not transmittable to Nicotiana benthamiana. To identify the existence of CGMMV particle, the virus was purified from figleaf gourd and cucumber growing together in the graft system. CGMMV solution extracted from the cucumber represented a typical absorption spectrum of the virus but that from the figleaf gourd did not. Only a few CGMMV particles were observed in the purified preparation from the figleaf gourd. These results confirmed that CGMMV only passed through figleaf gourd in the grafting system. This study indicated that figleaf gourd is not a host of CGMMY.