• Korean journal of applied entomology
• /
• v.23 no.4 s.61
• /
• pp.203-208
• /
• 1984

Four varieties of tobacco, Nicotiana tabacum var. NC 2326. NC 95, NC 744 and Havana. and two plant species, Physalis floridana Rydb., N. repanda Wild. were used for classification of ten isolates of potato virus Y(PVY) obtained Iron potato or tabacco plants showing various symptoms. Each of the 10 isolates could be distinguished by the host reactions showing necrosis, vein banding and/or mottling, or no symptom on these hosts. Five isolates of PVY, PVY-VN, PVY-N, PVY-NSNR, PVY-Chile, and PVY-Argentina, showed necrotic symptom on NC 2326, but others showed vein handing and/or mottling symptom. On NC95, each of the isolates tested showed similar symptons as on NC2326, except necrotic symptom by the isolate PVY-MSNR. Havana showed mottling reaction to the PVY-NSNR, PVY-MSNR, PVY-MSMR, PVY-VB, and necrosis to PVY-Chile, PVY-Argentina, but showed no symptom to the others. NC744 showed mottling symptom to the PVY-MSNR and PVY-MSMR, necrosis to the PVY-Chile and PVY-Argentina, and no symptom to the others. On N. repanda, necrotic reaction to PVY-Argentina. no symptom to PVY-VN and PVY-C, and nettling to others were observed.

• The Plant Pathology Journal
• /
• v.32 no.1
• /
• pp.33-46
• /
• 2016

In this study, the full-length nucleotide sequences of four Iranian PVY isolates belonging to $PVY^N$ strain were determined. The genome of Iranian PVY isolates were 9,703-9,707 nucleotides long encoding all potyviral cistrons including P1, HC-Pro, P3, 6K1, CI, 6K2, VPg, NIa-Pro, NIb and CP with coding regions of 825, 1,395, 1,095, 156, 1,902, 156, 564, 732, 1,557 and 801 nucleotides in length, respectively. The length of pipo, embedded in the P3 cistron, was 231 nucleotides. Phylogenetic analysis showed that the Iranian isolates clustered with European recombinant NTN isolates in the N lineage. Recombination analysis demonstrated that Iranian $PVY^N$ isolates had a typical European $PVY^{NTN}$ genome having three recombinant junctions while $PVY^N$ and $PVY^O$ were identified as the parents. We used dN/dS methods to detect candidate amino acid positions for positive selection in viral proteins. The mean ${\omega}$ ratio differed among different genes. Using model M0, ${\omega}$ values were 0.267 (P1), 0.085 (HC-Pro), 0.153 (P3), 0.050 (CI), 0.078 (VPg), 0.087 (NIa-pro), 0.079 (NIb) and 0.165 (CP). The analysis showed different sites within P1, P3 and CP were under positive selection pressure, however, the sites varied among PVY populations. To the best of our knowledge, our analysis provides the first demonstration of population structure of $PVY^N$ strain in mid-Eurasia Iran using complete genome sequences and highlights the importance of recombination and selection pressure in the evolution of PVY.

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

• The Plant Pathology Journal
• /
• v.33 no.4
• /
• pp.382-392
• /
• 2017

This study reports the findings of a distinct Potato virus Y (PVY) isolate found in Northeast China. One hundred and ten samples (leaves and tubers) were collected from potato plants showing mosaic symptoms around the city of Harbin in Heilongjiang province of China. The collected tubers were planted and let to grow in a greenhouse. New potato plants generated from these tubers showed similar symptoms, except for one plant. Subsequent serological analyses revealed PVY as the causing agent of the disease. A novel PVY isolate (referred to as HLJ-C-44 in this study) was isolated from this sample showing unique mild mosaic and crisped leaf margin symptoms. The complete genome of this isolate was analyzed and determined. The results showed that HLJ-C-44 is a typical PVY isolate. Phylogenetic analysis indicated that this isolate belongs to the N-Wi strain group of PVY recombinants ($PVY^{N-Wi}$) and also shared the highest overall sequence identity (nucleotide and amino acid) with other members of this strain group. However, recombination analysis of isolate HLJ-C-44 revealed a recombination pattern that differed from that of other $PVY^{N-Wi}$ isolates. Moreover, biological assays in four different potato cultivars and in Nicotiana tabacum also revealed a different phenotypic response than that of a typical $PVY^{N-Wi}$ isolate. This data, combined, suggest that HLJ-C-44 is a novel PVY recombinant with distinct biological properties.

• 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.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 1995.06b
• /
• pp.77-96
• /
• 1995

To obtain basic informations for the improvement of seed potato production in Korea, some etiological properties of potato virus Y(PVY) distributed in the major seed potato production area(Daekwanryeong) were characterized, and the nucleotide and amino acid sequences of the coat protein gene of the PVY strains isolated were analyzed. PVY strains in Daekwonryeong, an alpine area, were identified to be two strains, PVYo and PVYN by symptoms of indicator plants, and their distribution in potato fields was similar. Major symptom on potato varieties by PVY was grouped as either mosaic alone or mosaic accompanied with veinal necrosis in the lower leaves. The symptom occurrence of the two symptoms was similar with Irish Cobbler, but Superior showed a higher rate of mosaic symptom than the other. The PVY strain which was isolated from potato cv. Superior showing typical mosaic symptoms produced symptoms of PVY-O on the indicator plants of Chenopodium amaranticolor, Nicotiana tabacum cv. Xanthi nc and Physalis floridana, but no symptom o Capsicum annum cv. Ace. Moreover, results from the enzyme-linked immunosorbent assay with monoclonal and polyclonal antibodies showed that the isolated PVY reacts strongly with PYV-O antibodies but does not react specifically with PVY-T antibodies. The purified virus particles were flexious with a size of 730$\times$11nm. On the basis of the above characteristics, the strain was identified to be a PVY-O and named as of PVY-K strain. The flight of vector aphids was observed in late May, however, the first occurrence of infected plants was in mid June with the bait plants surrounded with PVY-infected potato plants and early July with the bait plants surrounded with PVY-free potato plants. PVY infection rates by counting symptoms on bait plants (White Burley) were 1.1% with the field surrounded with PVY-free potato plants and 13.7% the fields surrounded with PVY-infected potato plants, showing the effect of infection pressure. The propagated PVY-K strain on tobacco(N. sylvestris) was purified, and the RNA of the virus was extracted by the method of phenol extraction. The size of PVY-K RNA was measured to be 9, 500 nucleotides on agarose gel electrophoresis. The double-stranded cDNAs of PVY-K coat protein(CP) gene derived by the method of polymerase chain reaction were transformed into the competent cells of E. coli JM 109, and 2 clones(pYK6 and pYK17) among 11 clones were confirmed to contain the full-length cDNA. Purified plasmids from pYK17 were cut with Sph I and Xba I were deleted with exonuclease III and were used for sequencing analysis. The PVY-K CP gene was comprised of 801 nucleotides when counted from the clevage site of CAG(Gln)-GCA(Ala) to the stop codon of TGA and encoded 267 amino acids. The molecular weight of the encoded polypeptides was calculated to be 34, 630 daltons. The base composition of the CP gene was 33.3% of adenine, 25.2% of guanine, 20.1% of cytosine and 21.4% of uracil. The polypeptide encoded by PVY-K CP gene was comprised of 22 alanines, 20 threonines, 19 glutamic acids and 18 glycines in order. The homology of nucleotide sequence of PVY-K CP gene with those of PVY-O(Japan), PVY-T(Japan), PVY-TH(Japan), PVYN(the Netherlands), and PVYN(France) was represented as 97.3%, 88.9%, 89.3%, 89.6% and 98.5%, respectively. The amino acid sequence homology of the polypeptide encoded by PVY-K CP gene with those encoded by viruses was represented as 97.4%, 92.5%, 92.9%, 92.9%, and 98.5%, respectively.

• Journal of the Korean Society of Tobacco Science
• /
• v.31 no.2
• /
• pp.69-74
• /
• 2009

Potato Virus Y (PVY), PVY-vein necrosis strain, causes severe damage at growth, yield and leaf quality on flue-cured tobacco in Korea. The development of PVY resistant flue-cured varieties without quality deterioration is therefore urgently desired. The flue-cured tobacco, KF120 (Korea Flue-cured 120), was a male-sterile (ms) $F_1$ hybrid derived from the cross between msKF117 and KF0007-7. msKF117 was developed from the cross of NC82 with N. africana and KF0007-7 was developed from the cross of KF117 with NC82. The agronomic characteristics and disease resistance of KF120 was evaluated during 2006-2007 field performance test. It showed better growth characteristics and yield performance than standard cultivar KF109. It had 2 more leaves per plant, flowered 2 days later than KF109. The yield of cured leaf of KF120 was increased by about 5% compared to KF109. The chemical composition and physical properties of the cured leaf of KF120 were as much acceptable as those of KF109. KF120 showed high resistance to PVY compared to KF109. It showed a similar mode of resistance to bacterial wilt and black shank as was found in KF109.

• Journal of the Korean Society of Tobacco Science
• /
• v.20 no.2
• /
• pp.153-159
• /
• 1998

The vein necrotic strain of Potato Virus Y (PVY - VN) and black shank (Phyto-phthora parasitica var. nicotianae) are the two major diseases causing severe damages especially in burley tobacco (N. tabacum L.) area in Korea. A new tobacco variety, KB 111, resistant to PVY and black shank disease, was developed by Korea Ginseng & Tobacco Research Institute in 1997. It is a male sterile(MS) F$_1$ hybrid of the cross between MS TC 613 and KB 108. KB 111 was compared to Burley 21 on the agronomic characteristics and disease resistances in performance tests: It possessed upright growth habit and flowered two days later than Burley 21. It was resistant to both PVY and black shank and yielded about 3% more cured leaf than Burley 21, but other characteristics are very simiar to those of Burley 21. The chemical composition and physical properties of the cured leaf of KB 111 were as much acceptable as those of Burley 21 while it produced average yield of good quality leaf and appeared to resistant to PVY and black shank disease on regional farm test in 1998.

• The Plant Pathology Journal
• /
• v.18 no.3
• /
• pp.130-137
• /
• 2002

Potato virus Y (PVY) is one of the most important viruses in many field crops in Korea. In this study, 31 PVY isolates were isolated from infected potato (Solanum tuberosum), tobacco (Nicotiana tabacum), pea (Pisum sativum), and weeds (Veronica persica, Lamium amplexicause and Capsella bursa-pastoris) showing different mosaic symptoms in Jeonbuk, Chungnam, Gangwon, and Gyeongbuk areas in Korea. The 640 nucleotide region containing the C-terminal portion of coat protein (CP) gene and 3'non-translated region (NTR) was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using PVY-specific oligonucleotide primers. Sequence analyses of the amplified DNA fragments showed that the C-terminal portion of CP gene was not significantly different from that of previously reported PVY strains from potato (PVY-OK and -T) and tobacco (PVY-VN) in Korea. Homologies of the deduced CP amino acid sequences were 93.3-99.0% to corresponding regions of the other PVY strains including PV $Y^{N}$, PV $Y^{o}$ , PV $Y^{OK}$ , PV $Y^{T}$ , and PV $Y^{VN}$ . In contrast the sequences located at the 3'-NTR showed more diverse sequence homologies (76.4-99.7%). These results indicate that the C-terminal portion of the CP gene was relatively conserved while sequences at the 3'NTR were more diverse and variable over the host species and the regions where they were isolated.e isolated.

• Journal of the Korean Society of Tobacco Science
• /
• v.19 no.2
• /
• pp.117-123
• /
• 1997

Viral coat protein (CP) encoding cDNA with artificial start and stop codons was synthesized by reverse-transcriptase polymerase chain reaction (RT-PCR) from the Korean isolate of potato virus Y-vein nectrosis strain (pVY-VN). To make PVY CP cDNA to untranslatable form, three stop codons were inserted near the start codon by "megaprimer-PCR" method. The untranslatable CP cDNA was subcloned to plant expression vector and transferred to N. tabacum cv. NC82 by Agrobacterium-mediated transformation. Highly resistant plants to PVY infection were screened, based on symptom development after mechanical virus inoculation. By genomic PCR and Southern blot analysis, one or more copies of the untranslatable CP gene were found in all transformants. From northern blot analysis, highly resistant transgenic lines had very low level of CP transcript but susceptible lines had high level, suggesting resistance to PVY infection should be related to RNA-mediated mechanism.mechanism.