• Korean Journal Plant Pathology
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• v.13 no.2
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• pp.118-124
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• 1997

The two viruses of barley yellow mosaic(BaYMV) and barley mild mosaic virus (BaMMV) were detected by ELISA from barley plants with virus-like symptoms which were collected from 16 locations in southern Korea, during 1995 and 1996. Both viruses occurred in southern Korea. Barley plants at Chongdo and Koseong were infected with BaMMV, while those infected with BaYMV were at Kurye and Taegu. After sowing 50 barley cultivars at habitually infected fields in 10 locations, the susceptibility and resistance to BaYMV and BaMMV were screened with antiserum tests. The cultivars of Albori, Alchanbori, Daejinbori, Jokangbori, Milyangbori, Boeunkwamek, Naehanssalbori, Olssalbori, Weossalbori, Dusan 29 and Deogndohyangchonkwa showed positive reaction to BaYMV antiserum, while Saeolbori, Chalbori, Jinjukwa and Baegjinkwa showed positive reaction to BaMMV. Nonsankwa 1-6 and wheat cultivars of Chongkeymil, Dahongmil, Grumil, Urimil, Jochonhomil, Sinkeyhomil showed negative reactions to both viruses. The rest cultivars were infected both with BaYMV and BaMMV. Sap inoculations to barleyplants with the two viruses of BaYMV isolated in Haenam and BaMMV isolated at National Honam Agricultural Station, expressed lower infection rate than those grown in the virus-infected fields.

• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.314-318
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• 1998

Using the reverse transcription polymerase chain reaction (RT-PCR), a rapid and sensitive assay method for the detection and identification of barley yellow mosaic virus (BaYMV) and barley mild mosaic virus (BaMMV) was adapted. Two units of primers from each virus were selected and used for the determination of two different viruses. PCR fragments of BaYMV (ca. 0.9kb) and BaMMV (ca. 0.8kb) were obtained from the designed method for the assay of BaYMV and BaMMV coat protein. PT-PCR fragments were cloned using vector pT7 Blue and the sequences of the selected clones were analyzed. coat protein of BaYMV and that of BaMMV consisted of 297 amino acids (891 nucleotides) and 251 amino acids (753 nucleotides), respectively. The snalysis of coat protein genes from these two viruses showed that 45.6% of nucleotides sequence ad 34.9% of amino acid in BaYMV were homologous to those in BaMMV.

• Korean Journal Plant Pathology
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• v.14 no.1
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• pp.68-73
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• 1998

Barley mild mosaic virus (BaMMV-Kor) was isolated from the southern part of Korea, and by mechanical inoculation onto barley cultivars, purification and production of antibody. BaMMV-Kor purified form infected plants were filamentous particle, with 13 nm in diameter and 250∼300 nm and 500∼650 nm in length. Antibody of BaMMV-Kor was made by injecting the purified virus to the muscle of a rabbit. In gel-diffusion test, antibody to BaMMV-Kor created spur with BaMMV-Kal and BaMMV-M, but did not make spur with BaMMV-Kor infected New Golden, Ishukushirazu, Joshushiro Hadaka and Misato Golden, but did not infect Kashimamugi, Chikurin Ibaraki 1 and Mokusekko 3. In Korean barley cultivars, BaMMV-Kor infected most of the covered barley cultivars, but did not infect Saeolbori. It also infected naked barley cultivars except Chalbori and Hinssalbori. And all the beer barley cultivars were infected by BaMMV-Kor. BaMMV-Kor had two RNAs, RNA 1 (7.5 Kb) and RNA 2 (3.5 Kb), and coat protein (33 KDa).

• The Plant Pathology Journal
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• v.27 no.4
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• pp.324-332
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• 2011

Soil-borne barley yellow mosaic disease caused by Barley yellow mosaic virus (BaYMV) or Barley mild mosaic virus (BaMMV) gives a serious threat to the winter barley cultivated in the southern regions in Korea. It is important to develop resistant varieties for stable and high-yield production. The objectives of this study were to evaluate 22 genotypes of exotic barley germplasms carrying the resistance genes rym1 through rym12, with the exception of rym10, and to determine the genes that confer resistance to BaYMV or BaMMV in Korea. Using the traditional visual scoring of symptoms at 4 locations over 3 years, average disease rate values differed (P < 0.001) among the genotypes. ELISA test revealed the presence of both BaYMV and BaMMV in all of the field sites but Jinju and significantly different rates of infection among genotypes and years. Barley genotypes differed in how virus quantities and pathogen-induced symptoms were correlated, especially in response to BaYMV. Disease incidence was affected by the climatic conditions present during the early growing stage before overwintering. A Chinese landrace, 'Mokusekko 3', carrying rym1 and rym5 was comparatively resistant at all locations studied. The barley genotypes carrying either rym6 or rym9 were susceptible to the viral strains. The genotypes carrying rym5 were resistant in Jinju and Milyang but susceptible in Iksan and Naju. The resistance genes rym2 and rym3 were effective in local strains and would be potent contributors to disease resistance.

• The Plant Pathology Journal
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• v.23 no.4
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• pp.260-265
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• 2007

Testing a large number of samples from field monitoring and routine indexing is cumbersome and the available virus detection tools were labor intensive and expensive. To circumvent these problems we established tissue blot immunoassay (TBIA) method an alternative detection tool to detect Barley mild mosaic virus (BaMMV) and Barley yellow mosaic virus (BaYMV) infection in the field and greenhouse inoculated plants for monitoring and routine indexing applications, respectively. Initially, leaf and stem were tested to determine suitable plant tissue for direct blotting on nitrocellulose membrane. The dilutions of antibodies were optimized for more efficient and economical purposes. Results showed that stem tissue was more suitable for direct blotting for it had no background that interferes in the reaction. Therefore, this technique was referred as direct stem blot immunoassay or DSBIA, in this study. Re-used diluted (1:1000) antiserum and conjugate up to 3 times with the addition of half strength amount of concentrated antibodies was more effective in detecting the virus. The virus blotted on the nitrocellulose membrane from stem tissues kept at room temperature for 3 days were still detectable. The efficiency of DSBIA and RT-PCR in detecting BaMMV and BaYMV were relatively comparable. Results further proved that DSBIA is a rapid, reliable and economical detection method suitable for monitoring BaMMV and BaYMV infection in the field and practical method in indexing large scale of barley materials for virus resistance screening.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.157-164
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• 2009

The complete nucleotide sequences of both RNA of an isolated Barley mild mosaic virus (BaMMV) from Iksan, Korea, have been determined. RNA1 was 7273 nucleotides long and encodes for a polyprotein of 2261 amino acids, which contains the eight putative functional proteins. RNA2 was 3520 nucleotides long and encodes for a polyprotein of 894 amino acids, which contains two functional proteins. Results of multiple sequence alignment showed 92.9% similarity with Na1 isolate, followed by Sil, UK(F), Asl1, Remis M and UK(M) isolates, respectively. Comparison of the BaMMV-Iks polyproteins with the corresponding proteins of BaMMV-Na1 isolates showed 95% amino acid sequence identity. The phylogenetic analysis revealed that Iks isolate was closely related to Na1 strain and have a common origin.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.348-352
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• 2006

Barley mild mosaic virus(BaMMV) is a soilborne Bymovirus vectored by root-infecting fungus, Polymyxa graminis. Mechanism of cultivar's resistance to BaMMV in field tests are difficult to assess since resistance could be either due to the virus or to P. graminis, or both. Whereas, available mechanical inoculation methods for BaMMV and other related viruses are labor intensive, give inconsistent results and generally result in low infection rates. Inoculation method using stick with gauze(SWG) was developed for BaMMV. The improved method proved to be simple, efficient, and reliable. The infected leaf tissues were preserved by drying in a frozen state under high vaccum(freeze dried barley infected leaves) to circumvent reduction of virus infectivity during storage. Five Korean barley cultivars were mechanically inoculated with BaMMV-infected sap by the improved method. Infection rates obtained were compared with natural infection. Cultivar Naehanssalbori showed resistance to BaMMV in the field trials but was found highly susceptible in the greenhouse tests by mechanical inoculation, indicating that the field resistance may be possibly due to resistance to P. graminis.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.859-866
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• 2015

Virus disease surveys on barley cultivation areas in Jeonnam Jeonbuk Gyungnam Gyungbuk-do were conducted during 2014-2015. In this study, we detected Barley yellow mosaic virus (BaYMV), Barley mild mosaic virus (BaMMV) and Soil-borne wheat mosaic virus (SBWMV) by RT-PCR from barley leaves. These viruses are of great economic importance for wheat and barley, causing significant quantitative and qualitative losses in yield. The result of investigation showed that the field incidence of BaYMV in Buan, Gimje was more than 90% in 2014. The infection field rate of barley virus including Boseong, Gangjin, Haenam, Jangheung in Jeonnam was ${\approx}$ 30%. In 2014, double infections by BaYMV and BaMMV was detected in Boseong, Gangjin, Haenam and Jangheung. Only as a low rate BaYMV occurred in various fields of Jeonbuk in 2015. At the same time high infection field ratio of 70% was observed in Gunsan. Also in Yeonggwang was double infection of BaYMV and BaMMV. BaYMV occurred single infection has been confirmed in all of the study area of Gyungbuk and Gyungnam except for Goseong during the investigation period.

• Research in Plant Disease
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• v.23 no.4
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• pp.363-366
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• 2017

Barley mild mosaic virus (BaMMV), Barley yellow mosaic virus (BaYMV) and Barley yellow dwarf virus (BYDV) have been identified as an important causative agents for an economically important disease of winter barley in Korea. In this study, a multiplex reverse transcription polymerase chain reaction (mRT-PCR) method was used for the simultaneous detection. Three sets of virus-specific primers targeted to the capsid protein coding genes of BaMMV, BaYMV and BYDV were used to amplify fragments that were 594 bp, 461 bp, and 290 bp, respectively. Several sets of primers for each target virus were evaluated for their sensitivity and specificity by multiplex RT-PCR. The optimum primer concentrations and RT-PCR conditions were determined for the multiplex RT-PCR. The mRT-PCR assay was found to be a better and rapid virus diagnostic tool of specific barley diseases and potential for investigating the epidemiology of these viral diseases.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.75.1-75
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• 2003

Barely yellow mosaic(BaYMV) and barely mild mosaic (BaMMV) bymoviruses are both transmitted by the soil-inhabiting fungus Polymyxa gramnis, and are responsible for economic losses in barley crops in Asia and Europe. Because chemical control of the vector is ineffective, the losses can only be prevented by growing resistant barley cultivars. The objective of this study is to produce resistant barley plants by transformation with viral coat protein(cp) genes. Resistance tests of T1 plants transformed with the BaYMV CP gene showed that at least four independent lines had clear resistance to BaYMV but two other lines were highly susceptible with severe symptoms. The CP gene was detected in all resistant T1 plants by genomic PCR. Most of T2 progenies derived from the resistant T1 lines also showed resistance. In contrast, only one out of 21 independent T2 lines transformed with the BAMMV CP gene tested showed clear resistance to BaMMV, and others were very susceptible. Further analyses of resistance and CP gene expression are in progress.