• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.2
• /
• pp.89-95
• /
• 2006

Potato plants carrying the Ry gene are extremely resistance to a number of potyviruses, but it is not known which variety expressed the resistance. In this investigation, combined classical and molecular techniques were used to identify virus resistance potatoes. Mechanical inoculation of 32 varieties of Korean potato cultivars, with potato virus Y (PVY), induced various symptoms, such as mosaic, yellowing, necrosis, mottle, vein clearing and vein bending. Different virus spreading patterns were observed, such as highly sensitive, moderate and resistant to $PVY^o$ inoculated leaves in different cultivars. From the results of double antibody sandwich-enzyme links immunosorbant assays (DAS-ELISA), coupled with reverse transcription polymerase chain reaction (RT-PCR), Winter valley and Golden valley were found to be highly susceptible and resistant cultivars to $PVY^o$ respectively. TEM was used as a complementary method to conform the localization of the virus in leaf tissues. TEM detect virus particles in Golden valley, where, ELISA and RT-PCR were unable to detect the CP gene. However, the interior part of the tissues was severely deformed in $PVY^o$ infected Winter valley, than Golden valley The Ry gene is involved in an induced response in $PVY^o$ infected Golden valley plants. The methods described in this study could be applied for the screening and development of antiviral potatoes.

• The Plant Pathology Journal
• /
• v.33 no.1
• /
• pp.101-101
• /
• 2017

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.138.1-138
• /
• 2003

Potato mop-top virus(PMTV) was identified from Solanum tuberosum cv. Gawon showing bright chlorotic mottle symptom in Namwon, Korea. Samples were collected green-house in February, 2003. Electron microscopic examination of negatively stained preparation revealed that PMTV were rigid-rod shaped particles about 100-150, 250-300 nm x 18-20 nm in length. In ultrathin sections of leaf tissue from diseased potato plants, cluster of viruses particles were observed in the cytoplasm. TAS-ELISA determined that the virus was serologically related to PMTV. PMTV produced double ring necrotic local lesion in inoculated leaf of Chenopodium amaranticolor in incubated at 15$^{\circ}C$. The PMTV could be detected with RT-PCR using PMTV detectable primer set designed to amplify about 540 bp of the partial CP gene of PMTV

• 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.

• Research in Plant Disease
• /
• v.12 no.1
• /
• pp.28-31
• /
• 2006

One of major potato viruses is Potato virus Y (PVY) in Korea. In the southern part of Korea, potatoes have been grown as double crops in a year by using cv. 'Dejima' and 'Chubak' due to very short dormancy. However, they have caused a serious problem such as a rapid degeneration. It has been thought that the degeneration is affected by the high incidence of PVY in neighboring potato fields. Therefore, the investigation of factors causing the degeneration is very important in the production of healthy seed potato. In this study, the PVY reinfection rates of several potato varieties and the different seed sources of cv. 'Chubak' have been investigated. Results show that the lowest infection rate of PVY among four potato cultivars derived from minitubers is cv. 'Superior'. The others are in order of 'Dejima', 'Atlantic' and 'Chubak'. Also, the incidences of PVY differ significantly when several seed sources are examined. When the seed potatoes (G2, the progeny of microtuber) as spring potato crops are planted in area without potato field nearby, the infection rate of PVY is as low as that of microtubers. However, PVY incidence in the progenies of minitubers as fall potato crops largely increases. Therefore, the best way of potato production under double cropping system is to use the healthy seed potato produced in area without potato field and plant relatively resistant cultivar such as Dejima.

• The Plant Pathology Journal
• /
• v.23 no.1
• /
• pp.13-21
• /
• 2007

Sweet potato feathery mottle virus(SPFMV) is one of the most prevalent viruses infecting sweet potatoes and occurs widely in sweet potato cultivating areas in Korea. To assess their genetic variation, a total of 28 samples infected with SPFMV were subjected to restriction fragment length polymorphism(RFLP) analysis using DNAs amplified by RT-PCR with specific primer sets corresponding to the coat protein(CP) region of the virus. The similarity matrix by UPGMA procedure indicated that 28 samples infected with SPFMV were classified into three groups based on the number and size of DNA fragments by digestion of CP-encoding regions with 7 enzymes including SalI, AluI, EcoRI, HindIII, FokI, Sau3AI, and DraI bands. Four primer combinations out of 5 designed sets were able to differentiate SPFMV and sweet potato virus G infection, suggesting that these specific primers could be used to differentiate inter-groups of SPFMV. Sequence analysis of the CP genes of 17 SPFMV samples were 97-99% and 91-93% identical at the intra-group and inter-groups of SPFMV, respectively. The N-terminal region of the CP is highly variable and examination of the multiple alignments of amino acid sequences revealed two residues(residues 31 and 32) that were consistently different between SPFMV-O and SPFMV-RC.

• The Plant Pathology Journal
• /
• v.22 no.4
• /
• pp.360-363
• /
• 2006

Efficacy of plant growth promoting rhizobacteria(PGPR) Bacillus vallismortis strain EXTN-1 has been proved in eliciting induced systemic resistance(ISR) in several crops. The present paper described the beneficial effects of EXTN-1 in potato as increase in yield and chlorophyll content, and plant protection against Potato Virus Y and X(PVY & PVX). EXTN-1 induced systemic resistance to the plants resulting in significant disease suppression in the field. Also the plants under treatment with EXTN-1 had higher chlorophyll content. The bacterized plants had significantly higher yields over the untreated control plants. The strain induced activation of defense genes, PR-1a and PDF 1.2 in transgenic tobacco model, which indicated the possible role of both SA, and JA pathways in EXTN-1 mediated plant protection against crop diseases.

• Korean Journal Plant Pathology
• /
• v.13 no.4
• /
• pp.219-224
• /
• 1997

A PT-PCR (reverse transcription-polymerase chain reaction) diagnostic method for potato virus Y (PVY) was developed using primer pair derived from conserved region of coat protein genes of several PVY strains, A 764 bp PCR product was detected from several lines of potato cv. Atlantic. We could prove that the 764 bp DNA fragment was indeed the PVY gene by sequencing analysis. PVY detection method using RT-PCR technique was about tuber tissue.

• The Plant Pathology Journal
• /
• v.16 no.2
• /
• pp.110-117
• /
• 2000

Potato virus X (PVX-KO) showing mild mosaic and stunting symptoms on potato (Solanum tuberosum) in Kangwon area has been isolated and characterized. EM observation of the purified virus particles showed flexuous rod shape of about 520 nm in length. The coat protein (CP) of the virus had a molecular weight of 31 kDa in SDS-PAGE analysis, and the viral RNA was approximately 6.4 kb in size in denatured agarose gel electro-phoresis. In gel-immunodiffusion tests, it reacted strongly with an antiserum to common PVX from BIOREABAAG (USA). A rabbit antiserum was produced using purified virus and used for routine PVX detection by ELISA. Cultivated potatoes in Kangwon and other areas were frequently infected with PVX-KO. Both Datura stramonium and Nicotiana tabaccum cultivars developed necrotic local lesions 5 days after inoculation, and systemic mosaic symptoms with vein clearing 2 weeks after inoculation. All the features agree with the description of other PVX strains. To confirm and determine PVX strains, reverse transcription-polymerase chain reaction experiment was conducted using specific primers for viral CP. Amplified DNA fragments were cloned and sequenced. Results showed nucleotide sequence homologies of about 88 to 99% to other PVX strains. Based on CP amino acid sequence deduced from nucleotide sequences and host range studies PVX-KO is considered a member of the type X subgroup of PVX.

• The Plant Pathology Journal
• /
• v.34 no.5
• /
• pp.451-457
• /
• 2018

The Sweet potato chlorotic fleck virus (SPCFV), of the genus Carlavirus (family Betaflexiviridae), was first detected as one of several viruses infecting sweet potatoes (Ipomea batatas L.) in Korea. Out of 154 sweet potato samples collected in 2012 that were showing virus-like symptoms, 47 (31%) were infected with SPCFV, along with other viruses. The complete genome sequences of four SPCFV isolates were determined and analyzed using previously reported genome sequences. The complete genomes were found to contain 9,104-9,108 nucleotides, excluding the poly-A tail, containing six putative open reading frames (ORFs). Further, the SPCFV Korean isolates were divided into two groups (Group I and Group II) by phylogenetic analysis based on the complete nucleotide sequences; Group I and Group II had low nucleotide sequence identities of about 73%. For the first time, we determined the complete genome sequence for the Group II SPCFV isolates. The amino acid sequence identity in coat proteins (CP) between the two groups was over 90%, whereas the amino acid sequence identity in other proteins was less than 80%. In addition, SPCFV Korean isolates had a low amino acid sequence identity (61% CPs and 47% in the nucleotide-binding protein [NaBp] region) to that of Melon yellowing-associated virus (MYaV), a typical Carlavirus.