• Research in Plant Disease
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• v.29 no.1
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• pp.52-59
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• 2023

Cucurbit chlorotic yellows virus (CCYV) is a plant virus that causes damage to cucurbit crops such as watermelon and cucumber, and is transmitted by an insect vector known as the whitefly. Since CCYV was first detected on cucumber in Chungbuk in 2018, it has been reported in other areas including Gyeongsang in Korea. In 2020, we performed field surveys of yellowing diseases in the greenhouses growing melon and watermelon in Chungbuk (Jincheon and Eumseong). Reverse transcription-polymerase chain reaction analysis of 79 collected samples including melon, watermelon, and weeds resulted in detection of CCYV in 4 samples: Three samples were singly infected with CCYV and one samples was mixed infected with CCYV, Cucurbit aphid borne yellows virus, and Watermelon mosaic virus. The complete genome sequences of the four collected CCYV melon isolates (ES 1-ES 4) were determined and genetically compared with those of previously reported CCYV isolates retrieved from GenBank. Phylogenetic analyses of RNA 1 and 2 sequences revealed that four ES isolates were clustered in one group and closely related to the CCYV isolates from China. The analysis also revealed very low genetic diversity among the CCYV ES isolates. In general, CCYV isolates showed little genetic diversity, regardless of host or geographic origins. CCYV has the potential to pose a serious threat to melon, watermelon, and cucumber production in Korea. Further studies are needed to examine the pathogenicity and transmissibility of CCYV in weeds and other cucurbits including watermelon.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1324-1330
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• 2017

Complete genome sequences of three new plant RNA viruses, Spinach deltapartitivirus 1 (SpDPV1), Spinach amalgavirus 1 (SpAV1), and Spinach latent virus (SpLV), were identified from a spinach (Spinacia oleracea) transcriptome dataset. The RNA-dependent RNA polymerases (RdRps) of SpDPV1, SpAV1, and SpLV showed 72%, 53%, and 93% amino acid sequence identities with the homologous RdRp of the most closely related virus, respectively, suggesting that SpDPV1 and SpAV1 were novel viruses. Sequence similarity and phylogenetic analyses revealed that SpDPV1 belonged to the genus Deltapartitivirus of the family Partitiviridae, SpAV1 to the genus Amalgavirus of the family Amalgaviridae, and SpLV to the genus Ilarvirus of the family Bromoviridae. Based on the demarcation criteria, SpDPV1 and SpAV1 are considered as novel species of the genera Deltapartitivirus and Amalgavirus, respectively. This is the first report of these two viruses from spinach.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.87-90
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• 1995

Complementary DNA of the movement protein (MP) gene of tobacco mosaic virus Korean pepper strain (TMV-KP) was synthesized from purified TMV-KP RNA by using the reverse transcription and polymerase chain reaction (PCR) system. The synthesized double stranded cDNA was cloned into the plasmid pUC9 and transformed into Escherichia coli JM110. The movement protein gene of TMV-KP of the selected clones was subjected to sequence analysis by Sanger's dideoxy chain termination method. The complete sequence of viral MP gene from TMV-KP strain was 807 nucleotides long. The nucleotide of MP gene from TMV-KP has thirteen and two nucleotide differences from TMV vulgarae (TMV-OM) and Korean (TMV-K) strains, respectively. Thus, the nucleotide sequence of TMV-KP MP gene showed higher homology of 99% with that of TMV-K MP gene.

• Research in Plant Disease
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• v.23 no.3
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• pp.262-267
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• 2017

Throughout year 2015 to 2016, 101 proso millet and 200 sorghum samples were collected from five provinces in South Korea. The samples were subjected to paired-end RNA sequencing and further analyzed by RT-PCR. The results indicated that Rice black-streaked dwarf virus (RBSDV) was detected from sorghum collected in Gyeongsang province. The other four viruses, including RBSDV, Rice stripe virus (RSV), Barley virus G (BVG), and Cereal yellow dwarf virus (CYDV), were detected from proso millet. Among four viruses, both RSV and RBSDV were identified high frequency from proso millet collected from Gyeongsang province. Otherwise, BVG was nearly equally identified from five provinces, suggesting that the virus was supposedly widespread nationwide. RBSDV was first identified from both proso millet and sorghum in South Korea. The other virus annotated CYDV identified proso millet was shown to have relatively low identities compared to CYDV previously reported, suggesting that the virus might be new member of Polerovirus.

• Research in Plant Disease
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• v.23 no.1
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• pp.69-74
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• 2017

In 2015, a nationwide survey was carried out to investigate about occurrence pattern of virus infecting foxtail millet. A total 100 foxtail millet leaf samples showing virus-like and abnormal symptoms were collected in the seven main cultivated regions of Korea. Four viruses were identified using reverse transcription polymerase chain reaction and RNA sequencing. Of the collected 100 foxtail millet samples, 10 were Barley virus G (BVG), 4 were Rice stripe virus (RSV), 1 was Northern cereal mosaic virus (NCMV), and 1 was Sugarcane yellow leaf virus (ScYLV) infection. To our best knowledge, this is the first report of BVG and NCMV infecting foxtail millet in Korea and ScYLV is expected as new Polerovirus species. This research will be useful in breeding for improved disease-resistant foxtail millet cultivars.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.533-540
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• 2022

Thunberg fritillary (Fritillaria thunbergii), a perennial used in traditional Chinese herbal medicine, is a members of the family Liliaceae. The degeneration of germplasm is a severe problem in the production of Fritillaria thunbergii var. chekiangensis. However, no information about viral infections of F. thunbergii var. chekiangensis has been reported. In this study, we sequenced the small RNAs of F. thunbergii var. chekiangensis from leaves and bulbs, and viruses were identified using a phylogenetic analysis and BLAST search for sequence. In addition, multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) was used to rapidly detect viruses in this variety. Our study first reported that five viruses infected F. thunbergii var. chekiangensis. Among them, fritillary virus Y (FVY), lily mottle virus (LMoV), Thunberg fritillary mosaic virus (TFMV), and hop yellow virus (HYV) had been reported in F. thunbergii, while apple stem grooving virus was first reported in the genus Fritillaria. A multiplex RT-PCR method was developed to rapidly test the four viruses FVY, LMoV, TFMV, and HYV in F. thunbergii var. chekiangensis. Our results provide a better understanding of the infection of F. thunbergii var. chekiangensis by viruses and a basic reference for the better design of suitable control measures.

• The Plant Pathology Journal
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• v.22 no.1
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• pp.51-62
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• 2006

Three strains of Cucumber mosaic virus (CMV) have been found to cause a lethal disease, referred to as fern leaf syndromes and mild mosaic symptoms in tomato (Lycopersicon esculentum Mill.) crops grown in Kuwait. CMV strains were detected and identified based on host range, symptomatology, serology, electron microscopy, and ribonucleic acid (RNA) electrophoresis in polyacrylamide gels. A high degree of viral genomic heterogeneity was detected among CMV strains isolated in Kuwait, with no apparent correlation to symptomatology in tomato host plants. Two different virus satellites of 'CMV associated RNA 5', designated CARNA 5, were detected in two virus strains that caused both lethal disease and mild symptoms, designated CMV-D1 and CMV-S1 respectively. CARNA5 was not detected in the third CMV strain that caused fern leaf syndromes designated CMV-F. All the three isolated strains were serologically indistinguishable from each other and may belong to one serotype according to Ouchterlony gel diffusion tests. These strains transmitted via aphids (Myzus persicae Sulz) in a non-persistent manner. Physical properties of the virus strains were very similar where thermal inactivation test showed that virus withstood heating for 10 min at $70^{/circ}$, dilution end point was $10^{-4}$, and the longevity in vitro at room temperature was less than 5 days for all virus strains. CMV-D1 and CMV-F were the most devastating diseases spreading in both greenhouse and field-grown tomato where aborted flower buds failed on fruit setting due to the viral infection. This is the first report to isolate three different strains of CMV in Kuwait.

• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.105-109
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• 2015

Andean potato latent virus (APLV) is a phytopathogenic virus that belongs to the Group IV (+) sense ssRNA viruses of the genus Tymovirus. It mainly infects potatoes and is specified as a controlled quarantine virus in Korea. In this study, two primer sets of RT-PCR and nested PCR [set 2 ($404{\rightarrow}259bp$) and set 23 ($501{\rightarrow}349bp$)], were selected, which can rapidly and accurately diagnose APLV in quarantine sites. In addition, a modified-positive control plasmid is development, can possible verification of laboratory contamination in diagnosis of APLV detection. The PCR-base system developed in this study is expected to diagnose APLV and contribute to the plant quarantine in Korea.

• Research in Plant Disease
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• v.12 no.1
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• pp.25-27
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• 2006

Rice dwarf phytoreovirus (RDV), a member of the family Reoviridae has a genome composed of 12 segmented dsRNAs designated as 51 to 512 with an increasing order of mobility in polyacrylamide gel electrophoresis (PAGE). RDV encode 12 structural and non-structural proteins, $P1{\sim}P12$ which are encoded by the $S1{\sim}S12$ segments of the dsRNA genome, respectively. In this experiment, we confirmed in situ localization of RDV particles and P12 in cytoplasm of infected rice plant. We observed specific reaction of the gold particles using virus particle and P12 protein specific antiserum with protein A-gold immunolabelling in electron microscope. It was observed that gold particles specifically react to virus particles in cytoplasm in case using the antiserum for virus particles. In the case of antiserum for P12 protein, gold particles sporadically existing on cytoplasm without existing in organelle of cytoplasm specifically. As this result, RDV P12 protein encoded by S12 located in cytoplasm.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.44-52
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• 2011

Field surveys were conducted in 45 stone fruit orchards in seven districts of Isparta Province located in western Mediterranean region of Turkey important for stone fruit production. Leaf samples were collected from 175 trees showing virus-like symptoms. These samples were first tested by ELISA for five different RNA viruses including Apple mosaic ilarvirus (ApMV), Prunus necrotic ringspot ilarvirus (PNRSV), Prune dwarf ilarvirus (PDV), Plum pox potyvirus (PPV), Apple chlorotic leafspot trichovirus (ACLSV). While no ApMV and PPV infection was found, 46, 24 and 16 samples were tested positive for PDV, ACLSV and PNRSV, respectively, in ELISA showing about 45% of symptomatic trees in the region were infected with at least one of these viruses. In addition, it was found that nine sweet cherry trees were mixed infected with two or three of these viruses and PDV with an infection rate of 26.3% was the most widespread virus in symptomatic trees in western Mediterranean region. Thirty samples were selected and tested by a multiplex RT-PCR (mRT-PCR) for simultaneous detection of these viruses. While PPV was not detected, more than half of the tested 20 samples were individually or mixed infected with ApMV, ACLSV, PNRSV and PDV. The mRT-PCR results were confirmed by detection of these viruses individually in some of the field samples using RT-PCR with primes specific to each virus. Comparison of ELSA and mRT-PCR results of 30 samples showed that numbers of infected and mixed infected samples as well as infection and mixed infection rates were significantly higher in RT-PCR (20 and 66.7%) than in ELISA (14 and 46.7%). The results confirm that mRT-PCR is more sensitive than ELISA.