• Research in Plant Disease
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• v.28 no.4
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• pp.237-244
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• 2022

Chrysanthemum plants are one of the most economically important plants in South Korea. Both virus and viroid can cause diseases and economic damage to the plants. In this study, we investigated the detection of seven viruses and two viroids in 350 chrysanthemum plants cultivated in Yesan-gun, Chungcheongnam-do. Two viruses, chrysanthemum virus B (CVB) and tomato aspermy virus (TAV), and two viroids, chrysanthemum chlorotic mottle viroid (CChMVd) and chrysanthemum stunt viroid (CSVd), were detected in this study. The two viruses were detected in six samples and one sample, respectively. The two viroids were detected in 97 samples and 21 samples, respectively. The nucleotide sequences of the CVB-CN-Y, TAV-CN-Y, CChMVd-CN-Y, and CSVd-CN-Y obtained in this study showed 83.7-86.9%, 99.2-100.0%, 94.4-99.5%, and 95.7-99.7% identity, respectively, compared to their other strains/isolates. The CVB-CN-Y and TAV-CN-Y showed the greatest nucleotide sequence homology to CVB-GS1 and three TAV isolates (TAV-V, TAV-P, and TAV-ChJ), respectively. The CChMVd-CN-Y and CSVd-CN-Y showed the greatest nucleotide sequence homology to CChMVd-Horst and four CSVd isolates (Au1.1, K4pop, Sagae, and Tochigi), respectively. This study is the report on the infection rate of viruses and viroids in chrysanthemum plants cultivated in Yesan-gun in 2021.

• Research in Plant Disease
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• v.19 no.3
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• pp.220-225
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• 2013

For quarantine purpose, we developed the RT- and nested PCR module of Tomato black ring virus (TBRV), Arabis mosaic virus (ArMV), Cherry leafroll virus (CLRV) and Grapevine fanleaf virus (GFLV). The PCR modules, developed in this study make diagnosis more convenient and speedy because of same PCR condition. And also, the methods are more accurate because it can check whether the result is contamination or not using the mutation-positive control. We discard or return the 27 cases of Nepovirus infection seed by employing the module past 3 years. This study provides a rapid and useful method for detection of four quarantine plant viruses.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.349-354
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• 2005

A virus isolate collected from infected paprika (Capsicum annuum var. grossum) was characterized as Potato virus Y (PVY) based on biological, serological, cytopathological, and molecular properties. In host range studies, the paprika isolate produced the mosaic symptom on some tobacco, tomato and pepper (Capsicum annuum). A new paprika isolate also infected potato cultivars which is different biological characteristic compared to the other popular potyvirus infecting paprika, Pepper mottle virus (PepMoV). Previously reported PVY strains, $PVY^o$ and $PVY^N$ did not infect pepper and typical PepMoV isolates did not infect potato. Distinctive inclusion patterns of the scroll, pinwheel, long laminated inclusions, and helper components in the cytoplasm of infected cells were also different to those observed by the typical PVY isolate infections. However, the paprika isolate reacted to the monoclonal antibody of $PVY^N$ strain with high absorbance readings. RT-PCR amplification, cloning, and sequencing of the 3' untranslated region and a part of coat protein gene also added additional evidence of the paprika isolate as the $PVY^N$-related isolate. Multiple alignments as well as cluster dendrograms of PVY-paprika isolate revealed close phylogenetic relationship to the $PVY^N$ subgroup. Altogether, these results suggest that a new PVY isolate infecting paprika contained distinct characteristics compared to the other previously described PVY strains with closer relationship to the $PVY^N$ strain.

• Korean Journal of Organic Agriculture
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• v.23 no.1
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• pp.123-131
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• 2015

In this study, viral disease samples were obtained between 2006 and 2010 from pepper fields in 11 major pepper-growing districts in Gangwon-do, and in 83 areas from other provinces, with the exception of Gyeongsangnam-do and Jeju island in Korea. In order to assess the type of infection, field surveys were conducted with regard to viral disease severity and virus type, based on typical symptoms on leaves. The means of single and mixed-virus infections were 46.6% and 48.0%, respectively, during those periods, suggesting that viruses are the agents that most severely decrease pepper production in field cultivation in Korea. In terms of single infection, Cucumber mosaic virus (CMV) was the most prevalent virus based on its disease severity ratings (34.8%). Next, Pepper mild mottle virus (PMMoV) and Pepper mottle virus (PepMoV) were shown to cause severe viral diseases in pepper, with disease severities of around 5-10%. On the other hand, Tomato spotted wilt virus (TSWV) occurs in a limited area in Chungcheongnam-do and Jeollanam-do. Thus, the viral disease caused by CMV, PMMoV, and PepMoV in pepper can be severe, and these virus types should remain considered critical reasons for decreased pepper production in field cultivation in Korea. In addition to single infection, mixed infections are frequently observed in collected pepper samples from all areas. The ratios of mixed infection were therefore studied to evaluate the disease severity of mixed infections and to define individual virus types. These data showed that different types of viruses were present, and CMV was the most abundant virus for mixed infection, as in the case of single infection. Among mixed infections, the highest disease severity was seen with CMV+Broad beam wilt virus 2 (BBWV2), followed by other types of mixed infection such as CMV+PepMoV and CMV+PMMoV. However, further work is needed to reduce the severe damage caused by viruses and to assess mixed infection types involving three or more viruses.

• Korean journal of applied entomology
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• v.21 no.3 s.52
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• pp.153-158
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• 1982

The study was conducted to obtain the basic information on the diseases epidemics of vegetable crops grown in Namji, Jinju, Gimhae and Suncheon under the extremely varied and specified conditions, plastic film house. The disease survey was conducted from the end of April, 1951 to April 1982. Leaf mold and late blight were serious foliar disease in tomato during the seedling stage, especially when the infected seeds were sown. The diseases increased rapidly 35 days after seeding. In both continuous cultivation of cucumber and rotation with upland crops, incidence of Fusarium wilt was severe while incidence of the disease was negligible in cultivations after paddy rice or grafting on pumpkin. Downy mildew of cucumber was severe in Jinju and Suncheon area, however, it was not so serious in Namji area where the growing season of cucumber was unfavorable for the maximum disease incidence. Cucumber mosaic virus disease was prevalent in the areas surveyed and the disease incidence was increased rapidly after June. Powdery mildew prevailed at the early stage of cucumber growth after transplanting in Namji area. Root rot and wilting caused by Phytophthora capsici was as the most destructive disease in pepper grown under the vinyl house, especially in Namji and Jinju area where the pepper has been cultivated intensively. The Phytophthora attacked most parts of young plants during the winter time and then induced crown rot on the adults plants. Cultivation of pepper in vinyl house was almost impossible because of the Phytophora disease by the end of June. Virus diseases to tomato plants were prevalent throughout the surveyed area and the damage was also severe. In Jinju and Gimhae area leaf mold and late blight showed high infection rate in tomato during the harvest time.

• Research in Plant Disease
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• v.24 no.1
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• pp.66-74
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• 2018

Field surveys to investigate the incidence and occurrence pattern of viruses in red pepper were conducted during 2015-2016 in Korea. A total of 424 samples in 2015 and 368 samples in 2016 were collected based on selection of plants showing symptoms from farmer's field from every June to September. Reverse transcription-Polymerase chain reaction was used to test all samples for the presence of one or more of following viruses: Cucumber mosaic virus (CMV), Broad bean wilt virus 2 (BBWV2), Tomato spotted wilt virus (TSWV), Beet western yellows virus (BWYV), Pepper mottle virus (PepMoV), Potato virus Y (PVY) and Pepper mild mottle virus (PMMoV). The average disease incidence was 91.7% in 2015 and 98% in 2016 and the all seven viruses were found although there were different kinds of regions. The percent virus incidence in collected samples during 2015 was as follows: CMV, 73.8%; BBWV2, 68.3%; BWYV, 46.9%; PMMoV, 14.6%; TSWV, 12.7%; PepMoV, 6.6% and PVY, 3.3%. For 2016, incidence was as follows: CMV, 73.3%; BBWV2, 71.4%; BWYV, 34.7%; TSWV, 27.9%, PMMoV, 19.2%; PepMoV, 13.5% and PVY, 3.5%. Mixed infections were prevalent over single infections and infection rate was 83% and 86.7% in 2015 and 2016, respectively.

• The Plant Pathology Journal
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• v.23 no.2
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• pp.90-96
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• 2007

To overcome the problem of the yield reduction due to the viral satellite mediated protection, a culture mix of three nitrogen-fixing bacteria species of the genus Azospirillum (A. brasilienses N040, A. brasilienses SP7, and A. lipoferum MRB16), and one strain of cyanobacteria (Anabena oryzae Fritsch) were utilized as biofertilizer mixture in both greenhouse and field experiments. When protected plants were treated with biofertilizer mixtures, the fruit yield of biofertilized plants increased by 48% and 40% in a greenhouse and field experiment, respectively, compared to untreated plants inoculated with the protective viral strain alone. Polyacrylamide gel electrophoresis (PAGE) analysis of total nucleic acid (TNA) extracts revealed that biofertilization did not affect the accumulation of the viral satellite RNA (CARNA 5) that is required for plant protection against other destructive viral strains of CMV. The yield increment was a good compensation for the yield loss caused by the use of the protective viral strain associated with CARNA 5.

• Research in Plant Disease
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• v.26 no.4
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• pp.283-288
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• 2020

In September 2017, vein clearing and yellowing symptoms resembling those caused by viruses were observed on leaves of Malva verticillata in Chungnam, Korea. Nucleic acids were extracted from leaves of five symptomatic plants and tested by reverse transcription polymerase chain reaction using four virus specific primer pairs including malva vein clearing virus (MVCV). Amplicons of the expected size (600 bp) were obtained from total RNA of all samples using the MVCV-specific primers. To confirm the presence of MVCV in symptomatic plants, the DNA fragments from three samples were purified, and directly sequenced. BLAST analysis revealed that it shared the highest nucleotide identity (99%) with a MVCV isolate from tomato (Mexico). The virus isolates obtained from the third re-inoculated Chenopodium was designated as Cm1-5. Tissue from Cm1, Cm3, and Cm5 isolates was mechanically sap inoculated into 23 indicator plants. Cm3 isolate induced chlorotic local and mosaic symptoms in Althaea rosea. Phylogenetic analysis based on coat protein gene of 19 MVCV isolates from 6 different countries and plant species, did not correlated with either the geographical origin of the isolates, or pathogenicity. To our knowledge, this study first reports the natural occurrence of MVCV on M. verticillata in Korea and characterization of three Korean isolates of MVCV.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.286-293
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• 2012

The resistance to Tobamovirus in Capsicum spp. has been known to be controlled by five different alleles ($L^0$, $L^1$, $L^2$, $L^3$, and $L^4$) of L locus on the telomere of long arm of pepper chromosome 11. To develop a set of molecular markers differentiating all the alleles of L locus, we used five pepper differential hosts including Capsicum annuum Early California Wonder (ECW, $L^0L^0$), C. annuum Tisana ($L^1L^1$), C. annuum Criollo de Morelos 334 (CM334, $L^2L^2$), Capsicum chinense PI 159236 ($L^3L^3$), and Capsicum chacoense PI 260429 ($L^4L^4$). Developing a series of CAPS or SCAR markers specifically linked to the alleles was allowed by the sequence comparison of PCR amplicons of the $L^3$-linked markers (189D23M, A339, and 253A1R) and BAC sequences (FJ597539 and FJ597541) in the pepper differentials. Genotypes deduced by these markers in 48 out of 53 $F_1$ hybrids of commercial pepper varieties were consistent with their phenotypes by bioassay using Tobamovirus pathotypes ($P_0$, $P_1$, and $P_{1,2$). Consequently, these markers can be useful to differentiate L alleles and for breeding Tobamovirus resistance in pepper with marker-assisted selection.