• Research in Plant Disease
• /
• v.19 no.2
• /
• pp.90-94
• /
• 2013

Potato cv. 'Haryeong' was bred with high solids, resistance to late blight and good culinary quality. It has been registered as new potato variety in 2005. Tuber necrosis symptoms such as severe superficial necrosis, raised surface lesions and ringed necrotic areas were found in tubers of 'Haryeong' during storage of seed potatoes in 2010. Potato virus Y (PVY) was detected from these symptomatic tubers by the analysis of RT-PCR using a primer set specific to coat protein gene of PVY. The nucleotide sequence of RT-PCR product ($PVY^{Hkr}$) was determined and compared to those of other strains, such as $PVY^{Kor}$, $PVY^N$, $PVY^{NTN}$, $PVY^O$, and $PVY^C$ registered in GeneBank. The result showed that $PVY^{Hkr}$ was exactly the same as $PVY^{Kor}$, Korean isolate reported in 2005, except two nucleotides. To verify the PVY was responsible for the tuber necrosis symptoms shown in the tubers of 'Haryeong', a bioassay was done using two viruses (PVY and Potato leafroll virus) and five potato cultivars ('Haryeong', 'Superior', 'Atlantic', 'Dejima', and 'Chubaek'). As expected, the same necrosis symptom appeared in tubers of 'Haryeong' infected with PVY only during the storage period.

• Korean journal of applied entomology
• /
• v.14 no.2 s.23
• /
• pp.59-63
• /
• 1975

A total of 40 virus infected tobacco plants (Nicotiana tabaccum L.) with various symptom types Were collected from Bucheon and Jeonju area by its symptoms were investigated on the incidence of tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), alfalfa mosaic virus (AMV), potato virus X (PVX) and potato virus Y (PVY) by serological methods. van Slogteren's microprecipitin test was applied for the testing of PVX and PVY from infected plants and Ouchterlony agar double diffusion test was used for CMV, TMV and AMV. Results obtained are as follows: 1. TMV, CMV, AMV, PVX and PVY wcre found to occur on the tobacco plants growing in Korea. 2. The prevalence of each of these viruses among the 40 tobacco plants investigated was in the order of AMV: $(67.5\%)>CMV:(60.0\%)>TMY:(47.5\%)>PVY:(17.5\%)>PVX: (10.0\%).$ 3. In Burley variety, the percentage of infection by TMV was $15\%$, whereas it was as high as $80\%$ in Hicks variety. 4. Among the 40 tobacco plants investigated, $37.5\%$ showed infection with one kind of virus whereas the remaining $62.5\%$, revealed mixed infection with more than two different viruses.

• The Plant Pathology Journal
• /
• v.32 no.4
• /
• pp.321-328
• /
• 2016

We examined the effects of temperature on acquisition of Potato virus Y-O (PVY-O), Potato virus A (PVA), and Potato leafroll virus (PLRV) by Myzus persicae by performing transmission tests with aphids that acquired each virus at different temperatures. Infection by PVY-O/PVA and PLRV increased with increasing plant temperature in Nicotiana benthamiana and Physalis floridana, respectively, after being transmitted by aphids that acquired them within a temperature range of $10-20^{\circ}C$. However, infection rates subsequently decreased. Direct qRT-PCR of RNA extracted from a single aphid showed that PLRV infection increased in the $10-20^{\circ}C$ range, but this trend also declined shortly thereafter. We examined the effect of temperature on establishment of virus infection. The greatest number of plants became infected when N. benthamiana was held at $20^{\circ}C$ after inoculation with PVY-O or PVA. The largest number of P. floridana plants became infected with PLRV when the plants were maintained at $25^{\circ}C$. PLRV levels were highest in P. floridana kept at $20-25^{\circ}C$. These results indicate that the optimum temperatures for proliferation of PVY-O/PVA and PLRV differed. Western blot analysis showed that accumulations of PVY-O and PVA coat proteins (CPs) were lower at $10^{\circ}C$ or $15^{\circ}C$ than at $20^{\circ}C$ during early infection. However, accumulation increased over time. At $25^{\circ}C$ or $30^{\circ}C$, the CPs of both viruses accumulated during early infection but disappeared as time passed. Our results suggest that symptom attenuation and reduction of PVY-O and PVA CP accumulation at higher temperatures appear to be attributable to increased RNA silencing.

• Korean journal of applied entomology
• /
• v.8
• /
• pp.7-9
• /
• 1969

거의 모든 국가에서 생산된 씨감자는 감자바이러스 이병율을 검사해서 합격품만을 농민에 분배하고 있다. 우리나라는 딴 씨감자 생산국과는 사정이 달라 고령지에서 씨감자를 생산하고 있는 관계로 감자밭의 필수는 전국적으로 막대한 수에 달한다. 우리나라에서의 감자바이러스 김정은 원원종에 한하고 있으나 농민에 분배되는 씨감자도 바이러스 검정을해서 합격품만을 나누어주어야 국가의 체면이 서겠다. 그러나 현재의 시설로는 이를 감당 할 수 없어 이에 대치 될 만한 실제적 방법의 하나로 매개진딧물 밀도와 감자바이러스 이병율간의 상관관계를 밝혀 번잡한 바이러스 검정법 대신 매개진딧물의 공중밀도를 조사하여 해지점의 감자바이러스 이병율을 추산 할 목적으로 본 시험에 착수하였다. 본 보고에서는 진딧물조사 결과만을 발표하고 18개소에서 행한 포장시험결과는 1970년에 행할 바이러스 검정을 마치면 종합결과를 발표 할 예정이다. 표 1에서와 같이 서해안, 내륙, 및 대관령에서의 매개진딧물과 일반진딧물의 수는 각각 8/31, 179/680 및 50/237이었으며 필자가 행한 1967, 1968년의 조사성적을 뒷받침하는 결과를 얻었다. 이에 필자는 씨감자 부족량 약 60,000톤의 조속한 충족을 위해 씨감자의 증식 단계에서는 서해안 일모작 답을 환용 할 것을 다시 한번 강조하는 바이다.

• The Plant Pathology Journal
• /
• v.21 no.3
• /
• pp.258-261
• /
• 2005

We conducted a survey on pepper virus diseases in 31 regions in Korea from November 2001 to December 2004. Using electron microscopy, test plant reaction, rapid immuno-filter paper assay (RIPA), reverse transcription-polymerase chain reaction (RT-PCR) and/or analysis of viral nucleotide sequences, we found a number of viruses from 1,056 samples that we collected. These included Cucumber mosaic virus (CMV), Pepper mottle virus (PepMoV), Pepper mild mottle virus (PMMoV), Broad bean wilt virus 2 (BBWV2), Tobacco mild green mosaic virus (TMGMV), and Tomato spotted wilt virus (TSWV). Of the samples analyzed, $343(32.5\%)$ were infected with CMV, $209(19.8\%)$ with PepMoV, $141(13.4\%)$ with PMMoV, $12(1.1\%)$ with BBWV2, $40(3.8\%)$ with TMGMV, $5(0.5\%)$ with TSWV, $153(14.5\%)$ with CMV and PepMoV, $54 (5.1\%)$ with CMV and PMMoV, $31(2.9\%)$ with PepMoV and PMMoV, $3(0.3\%)$ with CMV and BBWV2, $1(0.1\%)$ with CMV, PepMoV and BBWV2, $8(0.8\%)$ with CMV, PepMoV and PMMoV, and $30 (2.8\%)$ samples were infected with viruses which were not identified. CMV was the most predominant virus in all inspected fields and the number of the samples infected with PMMoV was relatively low as compared PepMoV infection level in pepper. TMGMV was only found in the southern part of Korea, while TSWV was isolated in Anyang and Yesan. However, we did not encounter in this survey the Alfalfa mosaic virus (AMV), Potato virus Y (PVY), Tobacco mosaic virus (TMV), and Pepper vein chlorosis virus (PVCV).

• Korean journal of applied entomology
• /
• v.57 no.4
• /
• pp.415-423
• /
• 2018

Aphid is a typical vector that transfers various kinds of viruses to potatoes. Therefore, it is very important to control aphids moving into potato fields. We investigated the seasonal movement pattern of aphids and its virus transmission rates mainly in the three seed potato production regions at highland in Gangwon-do, Korea. In addition, we identified the aphid species with over-wintering eggs collected from barks or twigs of total 57 tree species around potato fields in winter season. The peak time of summer and winter migration of aphid was at the mid-June and the early October, respectively. A 2.8% of total aphid trapped in yellow water-pan trap was turned out PLRV-borne, and the virus transmission rate was 15.4% by Myzus persicae and 9.1% by Macrosiphum euphorbiae. PLRV-borne aphids started to flow in from the late May, and virus transmission rate of aphid trapped in mid-June was the highest with 10.4%. Totally 14 species of aphid eggs wintered in the 17 species of trees including Acer pictum subsp. mono and Acer pseudosieboldianum at the 11 sites. In particular, because it is not certain that Betula platyphylla var. japonica and Yamatocallis hirayamae do transmit potato virus, but they over-wintered in host plants distributed over a wide area, further research on transmission ability is necessary.

• The Plant Pathology Journal
• /
• v.31 no.3
• /
• pp.219-225
• /
• 2015

The primary step for efficient control of viral diseases is the development of simple, rapid, and sensitive virus detection. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) has been used to detect viral RNA molecules because of its simplicity and high sensitivity for a number of viruses. RT-LAMP for the detection of Potato virus X (PVX) was developed and compared with conventional reverse transcription polymerase chain reaction (RT-PCR) to demonstrate its advantages over RT-PCR. RT-LAMP reactions were conducted with or without a set of loop primers since one out of six primers showed PVX specificity. Based on real-time monitoring, RT-LAMP detected PVX around 30 min, compared to 120 min for RT-PCR. By adding a fluorescent reagent during the reaction, the extra step of visualization by gel electrophoresis was not necessary. RT-LAMP was conducted using simple inexpensive instruments and a regular incubator to evaluate whether RNA could be amplified at a constant temperature instead of using an expensive thermal cycler. This study shows the potential of RT-LAMP for the diagnosis of viral diseases and PVX epidemiology because of its simplicity and rapidness compared to RT-PCR.

• The Korean Journal of Pesticide Science
• /
• v.5 no.1
• /
• pp.1-11
• /
• 2001

Climate in the year of 2000 was characterized as a long severe drought in tile spring, unusually high and low temperature in summer, two times of typoons, and floods by heavy rains in fall. Rice leaf and panicle blast and bacterial grain rot occurred severely comparing with 1999 and Bipolaris leaf spot spread over tile country. Phytophthora blight and anthracnose in red-pepper became epidemic especially in the late season causing severe yield losses. Tomato fusaruim wilt, CGMMV, powdery mildew, and sudden wilt syndrom of cucurbits and strawberry powdery mildew were also severe in 2000. In garlic, sclerotium rot occurred severely mainly due to the frequent rainfalls in planting time and much snowfalls in 1999's winter. Spring potato had severe infection of viruses due to a long spring drought, and fall potato had high incidence of bacterial soft rot and bacterial wilt due to fall floods by heavy rains. In sweet potato fusarium wilt was the most severe as in other year. Disease incidence of apple and pear trees was rotatively mild compared with previous years. In wheat and barley, Gibberella petch rarely occurred because of spring drought.

• The Plant Pathology Journal
• /
• v.28 no.2
• /
• pp.123-136
• /
• 2012

Diseases caused by begomoviruses (family Geminiviridae, genus Begomovirus) constitute a serious constraint to tropical and sub-tropical agro-ecosystems worldwide. In recent years, they have also introduced in temperate regions of the world where they have great impact and are posing a serious threat to a variety of greenhouse crops. Begomoviral diseases can in extreme cases reduce yields to zero leading to catastrophic losses in agriculture. They are still evolving and pose a serious threat to sustainable agriculture across the world, particularly in tropics and sub-tropics. Till recently, there have been no records on the occurrence of begomoviral disease in South Korea, however, the etiology of other plant viral diseases are known since last century. The first begomovirus infected sample was collected from sweet potato plant in 2003 and since then there has been gradual increase in the begomoviral epidemics specially in tomato and sweet potato crops. So far, 48 begomovirus sequences originating from various plant species have been submitted in public sequence data base from different parts of the country. The rapid emergence of begomoviral epidemics might be with some of the factors like evolution of new variants of the viruses, appearance of efficient vectors, changing cropping systems, introduction of susceptible plant varieties, increase in global trade in agricultural products, intercontinental transportation networks, and changes in global climatic conditions. Another concern might be the emergence of a begomovirus complex and satellite DNA molecules. Thorough understanding of the pathosystems is needed for the designing of effective managements. Efforts should also be made towards the integration of the resistant genes for the development of transgenic plants specially tomato and sweet potato as they have been found to be widely infected in South Korea. There should be efficient surveillance for emergence or incursions of other begomoviruses and biotypes of whitefly. This review discusses the general characteristics of begomoviruses, transmission by their vector B. tabaci with an especial emphasis on the occurrence and distribution of begomoviruses in South Korea, and control measures that must be addressed in order to develop more sustainable management strategies.

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