• The Plant Pathology Journal
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• v.28 no.3
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• pp.248-258
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• 2012

Potato (Solanum tuberosum) is one of the most important food crops worldwide and yields of potato can be affected by virus infection. While more than 40 viruses have been found in potato, only nine viruses (potato leafroll virus, potato viruses A, M, S, V, X and Y, potato moptop virus and tobacco rattle virus) and one viroid (potato spindle tuber viroid) have a significant economic impact on potato, worldwide. This review describes the geographical distribution of the most important viruses infecting potato and the genes for resistance or tolerance that have been identified against these various infectious agents. In some cases such resistance genes have been found only in other Solanum species. Few genes for resistance to the vectors of these viruses have been obtained and even fewer have been deployed successfully. However, transgenic resistance in potato has been achieved against seven of these disease agents.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.407-415
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• 2014

Viral diseases have been a major limiting factor threating sustainable potato (Solanum tuberosum L.) production in Pakistan. Surveys were conducted to serologically quantify the incidence of RNA viruses infecting potato; Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus A (PVA), Potato virus M (PVM) and Potato leaf roll virus (PLRV) in two major potato cultivars (Desiree and Cardinal). The results suggest the prevalence of multiple viruses in all surveyed areas with PVY, PVS and PVX dominantly widespread with infection levels of up to 50% in some regions. Co-infections were detected with the highest incidence (15.5%) for PVX and PVS. Additionally the data showed a positive correlation between co-infecting viruses with significant increase in absorbance value (virus titre) for at least one of the virus in an infected plant and suggested a synergistic interaction. To test this hypothesis, glasshouse grown potato plants were challenged with multiple viruses and analyzed for systemic infections and symptomology studies. The results obtained conclude that multiple viral infections dramatically increase disease epidemics as compared to single infection and an effective resistance strategy in targeting multiple RNA viruses is required to save potato crop.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.416-424
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• 2014

Sweet potato is grown extensively from tropical to temperate regions and is an important food crop worldwide. In this study, we established detection methods for 17 major sweet potato viruses using single and multiplex RT-PCR assays. To investigate the current incidence of viral diseases, we collected 154 samples of various sweet potato cultivars showing virus-like symptoms from 40 fields in 10 Korean regions, and analyzed them by RT-PCR using specific primers for each of the 17 viruses. Of the 17 possible viruses, we detected eight in our samples. Sweet potato feathery mottle virus (SPFMV) and sweet potato virus C (SPVC) were most commonly detected, infecting approximately 87% and 85% of samples, respectively. Furthermore, Sweet potato symptomless virus 1 (SPSMV-1), Sweet potato virus G (SPVG), Sweet potato leaf curl virus (SPLCV), Sweet potato virus 2 ( SPV2), Sweet potato chlorotic fleck virus (SPCFV), and Sweet potato latent virus (SPLV) were detected in 67%, 58%, 47%, 41%, 31%, and 20% of samples, respectively. This study presents the first documented occurrence of four viruses (SPVC, SPV2, SPCFV, and SPSMV-1) in Korea. Based on the results of our survey, we developed multiplex RT-PCR assays for simple and simultaneous detection of the eight sweet potato viruses we recorded.

• Korean Journal of Microbiology
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• v.3 no.2
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• pp.1-8
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• 1965

The potato viruses, as possible potato virus X(PVX), potato virus Y(PVY), potato virus S(PVS) are isolated from potato tuber, which collected from eleven areas (Table 1) in Korea. These viruses are isolated by single lesion isolation, Aphid transmission and inoculating methods through the many species of the different plants. The PVX is identified by host range, symptoms, physical properties, serological reaction and electron micrography. The other two viruses are identified by the first two methods mentioned above. The results of the above experiments are as follows. The total value of these viruses infection is 81%. The value of PVX infection is higher than the other two viruses. The properties of PVX are marked as local lesions on Comphrena globosa. The dilution end point is $10^{-6}$, the thermal inactivation point is $70^{\circ}C$ and the size of virus particles is around 13 x 60 $m\mu$.

• Research in Plant Disease
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• v.9 no.1
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• pp.1-9
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• 2003

The occurrence of potato(Sotanum tuberosum) viral diseases caused by Potato virus X(PVX), Potato virus Y (PVY), Potato leafroll virus(PLRV), Potato vims S(PVS), Potato virus M(PVM), Potato virus A(PVA), Potato virus T(PVT), Alfalfa mosic virus(AIMV), Tobacco mosic virus(TMV), Potato mop top virus(PMTV) Tobacco rattle virus(TRV) and Potato spindle tuber viroid(PSTVd), potato witches' broom phytoplasma, have been identified so far in Korea. Major viral diseases such as PVX, PVY and PLRV had been studied more deeply, however, the others are just identified and only partially characterized since the first study on the relation between PVX nucleic acid and virus protein by Kim in 1961. The most studies on potato viral diseases are mainly focused on the problems of seed potato production. The National Alpine Agricultural Experiment Station(NAAES), since it began its activities in 1961, has given special attention to this problem by doing studies to identify, characterize and control potato virus diseases. This effort resulted in the development of new potato virus detection methods as a basis for elaborating new method of control, such as the production of seed potato free of virus and the selection of new virus-resistant transgenic potatoes. The further studies of potato viral diseases required would be fallowings: the continuous monitoring for the occurrence of identified or not identified potato viruses in Korea, the isolation of resistant viral genes, the development of control method for the non-persistently transmitted viruses like PVY, special vectors such as nematode and fungus transmitted viruses, TRV and PMTV and the development of control methods against potato viral diseases by viral cross protection, therapy, transgenic plant, and the use of the agents or molecules, such as virus inhibitors and antiviral proteins, etc., blocking viral replication.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.49.1-49
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• 1999

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.498-504
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• 2014

Potato virus Y (PVY) and potato leafroll virus (PLRV) are among the most damaging potato viruses and prevalent in most potato growing areas. In this study, cryopreservation was used to eradicate PVY and PLRV using two cryogenic methods. Potato shoot tips proliferated in vitro were cryopreserved through droplet-vitrification and encapsulation-vitrification using plant vitrification solution 2 (PVS2; 30% glycerol + 15% dimethyl sulfoxide + 15.0% ethylene glycol + 13.7% sucrose) and modified PVS2. Both cryogenic procedures produced similar rates of survival and regrowth, which were lower than those from shoot tip culture alone. The health status of plantlets regenerated from shoot tip culture alone and cryopreservation was checked by reverse transcription-polymerase chain reaction. The frequency of virus-free plants regenerated directly from highly proliferating shoot tips reached 42.3% and 48.6% for PVY and PLRV, respectively. In comparison, the frequency of PVY and PLRV eradication after cryopreservation was 91.3~99.7% following shoot-tip culture. The highest cryopreserved shoot tip regeneration rate was observed when shoot tips were 1.0~1.5 mm in length, but virus eradication rates were very similar (96.4~99.7%), regardless of shoot tip size. This efficient cryotherapy protocol developed to eliminate viruses can also be used to prepare potato material for safe long-term preservation and the production of virus-free plants.

• Journal of Plant Biotechnology
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• v.5 no.2
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• pp.101-105
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• 2003

To eradicate several viruses such as PVX, PVY, and PLRV which often cause considerable damages to the growth and yields of potatoes, several stems including shoot tips were excised from the potato plants grown for 50 days and electric shock was treated. Shoot tips excised from electric-shocked stems were transferred into the medium supplemented with antiviral compound, ribavirin to examine the combinatorial effect. When treated only with 20 mg/L ribavirin, PVX concentration in the regenerated plant-lets was slowly decreased as repeating sub-culture and finally, it took 32 weeks to reach completely PVX-free stock. With an electric shock treatment (10 mA electric current), all the replicates became free from PVY. However, PLRV was not completely eradicated from 94P70-4 and 93P29-3 lines even by treating with 10 mA electric shock. In this case, both electric shock and antiviral compound treatments in axillary buds from the stem segment were successful in eradicating viral contamination.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.126-129
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• 2002

Infected sweet potato (Ipomoea batatas) showing symptoms of sunken veins, stunting, mosaic, and mottling were collected from Gimje, Cochang, Iksan, and Haenam provinces in Korea. Electron microscopic (EM) observation of the infected tissue revealed rod and filamentous rod type virus particles of various lengths. Western blot analysis of the protein samples extracted from infected sweet potato and partially purified virus identified the isolates as Sweet potato feathery motile virus (SPFMV), Sweet potato latent virus (SwPLV), and Sweet potato chlorotic stint virus (SPCSV). Sweet potatoes were occasionally infected with more than one of these viruses. This is the first report of SwPLV and SPCSV in Korea.