• The Plant Pathology Journal
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• v.18 no.5
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• pp.237-243
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• 2002

A survey of virus infection in garlic plants cultivated in Korea was conducted for three years. Most virus-infected garlic plants (Allium sativum) showed typical symptoms on the leaves such as yellow mosaic, stripes, and distortion. Through immunosorbent electron micro-scopy and RT-PCR analysis, the complex mixtures of viruses including garlic viruses of the genus Allerivirus, gaylic strain of Leek yellow stripe virus of the genus Potyvirus, and Garlic latent virus of the genus Carlavirus were identified in the virus-infected garlic plants. Among these viruses, Allexivirus was the most frequently detect-ed in the regions surveyed. Using sets of differential primers for Allexivirus genomes, two members of the genus were amplified and sequenced from the purified viruses. The deduced amino acid sequences for the coat proteins and the nucleic acid binding proteins of two viruses showed high homologies to Garlic virus A (CarV-A) and Garlic virus D (GarV-D) of Allekivirus. This is the first report of GarV-A and GarV-D in Korea. This suggests that Allexivirus in gavlic plants in Korea was mixed and varied. Phylogenetic analyses showed that the genus Allexivirus was diversi(ied by the processes of accumulation and evolution of viruses in garlic plants due to the long period of repeated vegetative propagation.

• The Plant Pathology Journal
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• v.39 no.4
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• pp.374-383
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• 2023

Capsicum annuum (CA) is grown outdoors across fields in Jeollabuk-do, South Korea. The weeds surrounding these fields were investigated regarding the infection of 11 viruses infecting CA during the year 2014-2018. In the reverse transcription polymerase chain reaction diagnosis, 546 out of 821 CA samples (66.5%) were infected by nine viruses, and 190 out of 918 weed samples (20.7%) were infected by eight viruses. Correlation analysis of the mutual influence of the viruses infecting CA and weeds during these 5 years showed that five viruses had significant positive correlations with the infection in both CA and weeds. Over the study period, the weeds infected by cucumber mosaic virus (CMV) in the previous year were positively correlated with the incidence of CMV infection in CA in the current year, although the correlation was lower for tomato spotted wilt virus (TSWV) compared to CMV. The CMV infection percent was 14.0% in summer annuals, 11.4% in perennials, and 7.8% in winter annuals. However, considering the overwintering period without CA, the infection percent was 5.2% higher in winter annuals and perennials than that in summer annuals, indicating that winter annual and perennial weeds served as the main habitats for insect vectors. The TSWV infection percent in weeds was 10.4% in summer annuals, 6.4% in winter annuals, and 6.2% in perennials. The weeds surrounding CA fields, acting as the intermediate hosts, were found to be the potent sources of infection, influencing the spread and diversity of CA-infecting viruses. The results of this study can contribute to prevent viral infection in agricultural fields.

• Research in Plant Disease
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• v.24 no.1
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• pp.9-25
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• 2018

Plant viruses cause significant yield losses and continuously threaten crop production, representing a serious threat to global food security. Studies on plant-virus interactions have contributed to increase our knowledge on plant immunity mechanism, providing new strategies for crop improvement. The prophylactic managements consist mainly following international legislations, eradication of infected plants, and application of pesticide to decrease the population of vectors. Hence, putting together the pieces of knowledge related to molecular plant immunity to viruses is critical for the control of virus disease in fields. Over the last several decades, the outstanding outcomes of extensive research have been achieved on comprehension of plant immunity to viruses. Although most dominant R genes have been used as natural resistance genes, recessive resistance genes have been deployed in several crops as another efficient strategy to control viruses. In addition, RNA interference also regulates plant immunity and contribute a very efficient antiviral system at the nucleic acid level. This review aims at describing virus disease on crops and summarizes current resistance mechanisms. Furthermore, we will discuss the current biotechnological approaches to control viral diseases and the future questions that are to be addressed to secure crop production against viruses.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.150.1-150
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• 2003

A single-step multiplex reverse transcription polymerase chain reaction (RT-PCR) assay was developed for the simultaneous detection of five cucurbit-infecting viruses： cucumber mosaic virus (CMV), watermelon mosaic virus 2 (WMV2), zucchini yellow mosaic virus (ZYMV), cucumber green mottle mosaic virus (CGMMV), and kyuri green mottle mosaic virus (KGMMV). The multiplex RT-PCR provides a simple and rapid method for detecting various viruses in cucurbit plants, which will help diagnose many cucurbit plants at a time.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.164-168
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• 2001

Rice black-streaked dwarf virus (RBSDV) and Maize rough dwarf virus (MRDV) are closely related viruses. Since the two viruses produce identical symptoms on maize, barley, and wheat, diagnosis of infected plants is difficult. Previously, we reported that partial cDNA clones of RBSDV S5 and S6 from the Japanese isolate (RBSDV-H) have lower sequence homology to MRDV than do cDNA clones from other genomic segments. In order to test whether cDNA clones of RBSDV-H S5 and S6 can be used for molecular diagnosis, RBSDV field isolates from Korea and from Hokkaido, Japan were tested in dot blot hybridizations probed with RBSDV-H S5 and S6 cDNA colnes. Hybridization with these probes was more intense against the RBSDV genome than against the MRDV genome. Therefore, RBSDV-H S5 and S6 cDNA clones can be used to differentiate between the two viruses. Furthermore, RBSDV-H S5 and S6 clones reacted more strongly against the viruses from stunted maize plants from Korean fields than to MRDV, indicating that RBSDV may be the causal disease agent in maize plants in Korea.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.90-96
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• 2015

Garlic generally becomes coinfected with several types of viruses belonging to the Potyvirus, Carlavirus, and Allexivirus genera. These viruses produce characteristically similar symptoms, they cannot be easily identified by electron microscopy (EM) or immunological detection methods, and they are currently widespread around the world, thereby affecting crop yields and crop quality adversely. For the early and reliable detection of garlic viruses, virus-specific sets of primers, including species-specific and genus-specific primers were designed. To effectively detect the twelve different types of garlic viruses, primer mixtures were tested and divided into two independent sets for multiplex polymerase chain reaction (PCR). The multiplex PCR assays were able to detect specific targets up to the similar dilution series with monoplex reverse transcription (RT)-PCR. Seventy-two field samples collected by the Gyeongbuk Agricultural Technology Administration were analyzed by multiplex RT-PCR. All seventy two samples were infected with at least one virus, and the coinfection rate was 78%. We conclude that the simultaneous detection system developed in this study can effectively detect and differentiate mixed viral infections in garlic.

• The Plant Pathology Journal
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• v.35 no.1
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• pp.32-40
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• 2019

Symptoms of fig mosaic disease have been noticed on leaves of fig (Ficus carica) for several decades, in Montenegro. In 2014, leaf samples were collected from trees of six fig cultivars in a plantation located in the main fig-producing area of Montenegro, to study the disease. After RNA isolation, samples were tested by RT-PCR for detection of nine fig viruses and three viroids. Four viruses were detected: fig leaf mottle-associated virus 1 (FLMaV-1), fig mosaic virus (FMV), fig mild mottle-associated-virus (FMMaV) and fig badnavirus 1 (FBV-1). Most of the viruses were present in mixed infections. The amplicons of the viruses were directly sequenced from both directions. A BLAST search of these sequences revealed sequence identities with their closest counterparts at GenBank of 92, 97, 92 and 100%, for FLMaV-1, FMV, FMMaV and FBV-1, respectively. Different responses in symptom expression due to the various virus combinations detected have been demonstrated. Variety $Su{\check{s}}ilica$ had the least symptom expression, with only one virus (FBV-1) found. Considering that the production of figs in Montenegro is increasing and has a substantial relevance in this geographic location, the results indicate that more attention should be given to improving the phytosanitary condition of fig trees in the country.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.239-247
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• 2006

In 2003, a survey of sweet potato virus disease was carried out in seed boxes as well as in various sweet potato fields. Virus infection rate was $5\sim100%$ and 100% at seed boxes and fields, respectively. No relationship of the disease incidence and severity was observed between sweet potato cultivating areas and cultivars. A total of 179 samples were collected and analyzed based on serological, electron microscopic and molecular properties. Field-grown sweet potatoes were examined to inspect 8 different viruses using NCM-ELISA, resulting that 30% of sweet potato was infected by one virus, whereas 70% was by more than 2 viruses. However, RT-PCR using primers selected for seven viruses, such as Sweet potato feathery mottle virus (SPFMV) revealed that of one-hundred seventy-nine tested; 71 of SPFMV, 29 of SPGV, 19 of SPFMV+SPGV, 1 of SPFMV+SwPLV, 1 of SPFMV+SPLCV, 2 of SPFMV+SPGV+SwPLV, 6 of SPFMV+SPGV+SPLCV, 2 of SPFMV+SPGV+SwPLV+SPLCV and 48 of unknown viruses were identified from the field samples. In root, viral diseases were severer in Yeoju than in Mokpo Experiment Station and infection rate was much different depending on sweet potato cultivars.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.643-650
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• 2020

Korean ginseng (Panax ginseng) is a dicotyledonous, medicinal, perennial plant belonging to the genus Panax of the family Araliaceae. We investigated the occurrence and incidence of plant viruses in Panax ginseng in Korea. A total of 656 leaf samples were combined into one and total RNA was extracted from the polled sample, using RNA sequencing (RNA-Seq), a metatranscriptome analysis of the plant virome was conducted. The virus present in Panax ginseng was confirmed by reverse transcription polymerase chain reaction (RT-PCR) assay using virus-specific primers. In RNA-Seq data analysis, the multiplication protein of four viral contigs including Aristotelia chilensis virus 1 (AcV1), Turnip mosaic virus (TuMV), Watermelon mosaic virus (WMV), and Tobamovirus multiplication protein were discovered. From our metatranscriptome analysis and RT-PCR assay, TuMV and WMV were detected, whereas the three viruses reported in China such as tomato yellow leaf curl China virus; panax notoginseng virus A; and panax virus Y were not found in this study. The distribution of domestic ginseng viruses seems different from that recorded in China. Overall, this is the first plant virome analysis of Panax ginseng in Korea.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.93-97
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• 2011

For quarantine purpose, we selected five plant RNA viruses including Cucumber vein yellowing virus (CVYV), Cucurbit yellow stunting disorder virus (CYSDV), Potato aucuba mosaic virus (PAMV), Potato yellow dwarf virus (PYDV), and Tomato chlorosis virus (ToCV), which are not reported in Korea and cause serious economic losses to the family Cucurbitaceae or Solanaceae. To detect those viruses, we employed RT-PCR technique with specific oligonucleotide primer pairs and tested their detection efficiency for each virus. To design RT-PCR primers, coat protein was used for CVYV, CYSDV, and ToCV whereas RNA polymerase and nucleocapsid regions were used for PAMV and PYDV, respectively. The development of an RT-PCR based method proved a useful tool for rapid detection and identification of quarantine virus infections.