First Report of the Necrotic Strain of Potato virus Y (PVYN) on Potatoes in the Northwestern United States

More than 50 isolates of Potato virus Y (PVY) with characteristics of strains that cause tobacco veinal necrosis (PVYN) were obtained from potatoes (Solanum tuberosum L.) grown in the northwestern United States. These isolates are being characterized at the biological and molecular levels. Isolate RR1 was obtained from leaves of potato cv. Ranger Russet showing distinct mottling and leaf deformity, which is in contrast to the leaf-drop and necrosis usually observed with ordinary strains of PVY (PVYO) in this variety. Isolate AL1 was obtained from tubers of potato cv. Alturas showing distinct internal light brown rings and blotches. When RR1 and AL1 were transmitted to tobacco (Nicotiana tabacum L. cvs. Samsun NN and 423), they caused systemic veinal necrosis, including stem and petiole lesions typical of PVYN strains (2). Symptoms induced by RR1 and AL1 on tobacco appeared 9 to 11 days after inoculation, whereas some other isolates caused delayed veinal necrosis. All isolates that produced veinal necrosis on tobacco were detectable with PVY polyclonal antisera. Potato virus X was not detected by enzyme-linked immunosorbent assay in tobacco plants showing veinal necrosis. Some isolates, including AL1, failed to react in serological tests using PVYN-specific monoclonal antibodies obtained from three commercial sources. Other isolates, including RR1, were detectable with these monoclonal antibodies. Reverse transcription-polymerase chain reaction (RT-PCR) products obtained with primers specific for the coat protein (CP) open reading frame (ORF) were cloned and sequenced. AL1 possesses a CP more closely related to PVYO type isolates, which would account for its failure to react with PVYN monoclonal antibodies. In this regard, AL1 is similar to the PVYN-Wilga isolate (1). Other isolates that are detectable with the PVYN monoclonal antibodies possess a CP more consistent with N strains of the virus. Results of RT-PCR tests using primers derived from the P1 ORF sequence (3), and the restriction enzyme analysis and sequencing of the RT-PCR products, all suggest that AL1 and RR1 are related to European-type members of PVY tuber necrotic (NTN) or N strains. However, other isolates under investigation appear to be more closely related to previously reported North American NTN types (3). The symptomatology of these viruses on tobacco and potato, and the serological and molecular data clearly show that at least two distinct variants of PVYN have been found for the first time in a major potato production area of the United States, and pose a potential threat to the potato industry. References: (1) B. Blanco-Urgoiti et al. Eur. J. Plant Pathol. 104:811, 1998. (2) J. A. de Bokx and H. Huttinga. Potato virus Y. Descriptions of Plant Viruses. No. 242, CMI/AAB, Surrey, England, 1981. (3) R. P. Singh et al. Can J. Plant Pathol. 20:227, 1998.

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Identification of Potato virus Y Strains Associated with Tuber Damage During a Recent Virus Outbreak in Potato in Idaho

Plant Disease ◽

10.1094/pdis-92-9-1371a ◽

2008 ◽

Vol 92 (9) ◽

pp. 1371-1371 ◽

Cited By ~ 16

Author(s):

A. V. Karasev ◽

T. Meacham ◽

X. Hu ◽

J. Whitworth ◽

S. M. Gray ◽

...

Keyword(s):

United States ◽

Potato Virus ◽

Potato Virus Y ◽

Potato Production ◽

Russet Burbank ◽

Rt Pcr ◽

Tobacco Plants ◽

Commercial Potato ◽

Pcr Products ◽

Das Elisa

Potato virus Y (PVY) causes substantial losses in potato production by decreasing yields and affecting the quality of potato tubers. Management of PVY in potato is dependent primarily on potato seed certification programs to prevent or limit initial levels of virus inoculum. Prior to 1990, the ordinary strain of PVY (PVYO) was the predominant virus in North America. PVYO induces clear foliar symptoms in many potato cultivars, allowing successful management in seed potato through a combination of visual inspections and limited laboratory testing. In recent years, necrotic strains of PVY (PVYN, PVYNTN, and PVYN:O) have begun to spread in the United States, many of which induce mild symptoms in potato, making them more difficult to manage through visual inspections. In addition to reducing yield, necrotic isolates may also cause external and internal damage in tubers of susceptible cultivars, which is known as potato tuber necrotic ringspot disease (PTNRD). Tuber necrotic strains of PVY have been reported across the northern United States (1,2,4), although limited information is available on their incidence and spread in commercial potato production. During June and July of 2007, 38 random samples were collected from three different commercial fields displaying disease problems (cvs. Russet Ranger, Alturas, and Russet Burbank) in the vicinity of Idaho Falls, ID. Plants collected showed various degrees of mosaic and leaf yellowing. By using double-antibody sandwich (DAS)-ELISA and reverse transcription (RT)-PCR, 25 of these plants were identified as PVY positive. The mutiplex RT-PCR assay (3) confirmed that nine plants were infected with PVYNTN and 11 with PVYN:O. No RT-PCR products were amplified from five samples. During September and October of 2007, 25 tuber samples (cv. Russet Burbank) showing various degrees of unusual internal symptoms (e.g., brown spots) were collected near Idaho Falls, ID. Twenty-two tubers were found PVY positive by DAS-ELISA, and multiplex RT-PCR determined 13 of those were PVYNTN, three were PVYO, one was a PVYNTN/N:O mixture, and one was a PVYO/N:O mixture. No RT-PCR products were amplified from four samples. In October 2007, six tubers showing distinct external tuber damage characteristic of PTNRD (cv. Highland Russet) were collected near Twin Falls, ID. All six tubers were determined to be PVY positive by DAS-ELISA, and RT-PCR identified five as infected with PVYNTN and one with PVYN:O. All the mixtures were easily separated by inoculating tobacco plants followed by subsequent testing of individual plants. Asymptomatic tubers from the same lot not showing PTNRD damage were found PVY negative by DAS-ELISA and RT-PCR. All PVYNTN isolates collected during 2007 were inoculated into tobacco plants (Nicotiana tabacum L. cv. Xanthi) and confirmed to induce systemic vein necrosis. Limited sequencing of four of the PVYNTN isolates determined that they contained recombinant junctions 2 and 3, identifying them as being related to the European strain of PVYNTN (3). The data suggest an increase in distribution and incidence of necrotic strains of PVY in commercial, potato-production areas in Idaho during an outbreak in 2007 and the potential for an increase in PTNRD. References: (1) P. M. Baldauf et al. Plant Dis. 90:559, 2006. (2) J. M. Crosslin et al. Plant Dis. 90:1102, 2006. (3) J. H. Lorenzen et al. Plant Dis. 90:935, 2006. (4) L. M. Piche et al. Phytopathology 94:1368, 2004.

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Molecular Characterization of Recombinant Strains of Potato virus Y From Saudi Arabia

Plant Disease ◽

10.1094/pdis-05-15-0562-re ◽

2016 ◽

Vol 100 (2) ◽

pp. 292-297 ◽

Cited By ~ 14

Author(s):

Mohamad Chikh-Ali ◽

Hayam Alruwaili ◽

Dalton Vander Pol ◽

Alexander V. Karasev

Keyword(s):

United States ◽

Saudi Arabia ◽

Seed Potato ◽

Potato Virus ◽

Potato Virus Y ◽

The United States ◽

Tuber Quality ◽

Rt Pcr ◽

First Report ◽

Recombinant Strains

Potato virus Y (PVY) exists as a complex of strains, many of which are recombinants. The practical importance of PVY recombinant strains has increased due to their ability to induce potato tuber necrotic ring spot disease (PTNRD) that seriously affects tuber quality. In Saudi Arabia, potato production has increased fivefold during the last three decades, reaching 460,000 tons per year. Although PVY has been reported as one of the main viruses affecting potatoes, no information is available on PVY strains circulating in the country. In August 2014, a survey was conducted in a seed potato field at Al-Jouf, Saudi Arabia. PVY-positive samples selected based on visual symptoms and serological reactivity were subjected to strain typing using multiplex RT-PCR assays and were determined to represent recombinant PVY strains. Whole genome sequences were determined for two representative isolates, S2 and S9, through direct sequencing of a series of overlapping RT-PCR fragments for each isolate, and found to represent strains PVY-NE11 and PVYZ (SYR-III), respectively. One of the recombinant types, SYR-III, was previously found in nearby Syria and Jordan, but the second recombinant, PVY-NE11, was found before only in the United States. Both recombinants, PVY-NE11 and SYR-III, were previously found associated with PTNRD and thought to be rare. The current identification of PVY-NE11 and SYR-III in seed potato in a new geographic region suggests that these recombinants may not be as rare as previously believed. This is the first report on the occurrence of recombinant strains of PVY in potato in Saudi Arabia, and the first report on the PVY-NE11 strain of PVY found in potato outside of the United States.

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Identification and Geographic Distribution of Serotypes of Potato Virus Y

Plant Disease ◽

10.1094/pdis.1997.81.5.481 ◽

1997 ◽

Vol 81 (5) ◽

pp. 481-484 ◽

Cited By ~ 37

Author(s):

P. Ellis ◽

R. Stace-Smith ◽

G. de Villiers

Keyword(s):

Monoclonal Antibodies ◽

North America ◽

Geographic Distribution ◽

Potato Virus ◽

Potato Virus Y ◽

Potato Seed ◽

Seed Certification ◽

Strain Group ◽

Veinal Necrosis ◽

Potato Seed Certification

From a panel of 10 monoclonal antibodies (MAbs) prepared against specific isolates representing the three recognized strain groups of potato virus Y (PVY), i.e., common (PVYO), tobacco veinal necrosis (PVYN), and stipple streak (PVYC), seven were selected for serotype analysis. These MAbs were tested for reactivity with 52 PVY strains representing all three strain groups from an international collection. Within the PVYN strain group, five serotypes were identified and designated N1 to N5. The PVYO strain group was more diverse, and nine serotypes were defined and designated O1 to O9. Only one serotype, designated C1, was defined) within the PVYC strain group. The same panel of MAbs was used to test 632 PVY samples collected from potato seed certification plots in North America. Although no PVY(N) serotypes were found, all of the PVYO serotypes were identified, and several samples, tentatively assigned to the C1 serotype, were found.

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Biological and molecular characterization of various isolates of Potato virus Y-N (PVY-N) strain group

Plant Protection Science ◽

10.17221/10469-pps ◽

2017 ◽

Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽

pp. 278-280

Author(s):

J. Ptáček ◽

P. Dědič ◽

J. Matoušek

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Molecular Genetic ◽

Rt Pcr ◽

Nucleotide Level ◽

Tobacco Plants ◽

Specific Identification ◽

Pcr Products ◽

Necrotic Symptoms

Fourteen Potato virus Y (PVY) isolates were characterized. They represented PVYN strain only. However, application of serological and molecular genetic methods led to a more complicated characterization. For example, five isolates induced necrotic symptoms on tobacco plants typical of PVYN, despite reacting as PVYO serologically. Moreover, the PVY isolates were not identical according to molecular genetic properties. Typical PVYNTN PCR products were observed for 11 isolates, but four of them (Hr220-5, Hr387-7, Nord 242 and Syn1Scot) did not produce potato tuber necrotic symptoms in infected cultivars. An immunocapture RT-PCR probing was developed using a set of 24 primer pairs derived from eight regions of the PVY genome. Using this method, five out of seven PVYNTN isolates including the Czech standard PVYNTN from the potato cv. Nicola were found to be identical. However, two PVYNTN isolates and all the other probed PVY samples showed unique patterns, suggesting specific differences at the nucleotide level. This method enabled specific identification of individual isolates variability even within different PVY strains.

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Immunocapture-Multiplex RT-PCR for the Simultaneous Detection and Identification of Plant Viruses and Their Strains: Study Case, Potato Virus Y (PVY)

Plant Pathology - Methods in Molecular Biology ◽

10.1007/978-1-4939-2620-6_14 ◽

2015 ◽

pp. 177-186 ◽

Cited By ~ 2

Author(s):

Mohamad Chikh-Ali ◽

Alexander V. Karasev

Keyword(s):

Potato Virus ◽

Potato Virus Y ◽

Simultaneous Detection ◽

Plant Viruses ◽

Rt Pcr ◽

Detection And Identification ◽

Study Case

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Monitoring Current-Season Spread of Potato virus Y in Potato Fields Using ELISA and Real-Time RT-PCR

Plant Disease ◽

10.1094/pdis-03-12-0283-re ◽

2013 ◽

Vol 97 (5) ◽

pp. 641-644 ◽

Cited By ~ 17

Author(s):

Manphool S. Fageria ◽

Mathuresh Singh ◽

Upeksha Nanayakkara ◽

Yvan Pelletier ◽

Xianzhou Nie ◽

...

Keyword(s):

Real Time ◽

Potato Virus ◽

Potato Virus Y ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Pcr Assay ◽

Current Season ◽

Seed Market ◽

Polymerase Chain ◽

Time Of Harvest

The current-season spread of Potato virus Y (PVY) was investigated in New Brunswick, Canada, in 11 potato fields planted with six different cultivars in 2009 and 2010. In all, 100 plants selected from each field were monitored for current-season PVY infections using enzyme-linked immunosorbent assay (ELISA) and real-time reverse-transcription polymerase chain reaction (RT-PCR) assay. Average PVY incidence in fields increased from 0.6% in 2009 and 2% in 2010 in the leaves to 20.3% in 2009 and 21.9% in 2010 in the tubers at the time of harvest. In individual fields, PVY incidence in tubers reached as high as 37% in 2009 and 39% in 2010 at the time of harvest. Real-time RT-PCR assay detected more samples with PVY from leaves than did ELISA. A higher number of positive samples was also detected with real-time RT-PCR from growing tubers compared with the leaves collected from the same plant at the same sampling time. PVY incidence determined from the growing tubers showed a significant positive correlation with the PVY incidence of tubers after harvest. Preharvest testing provides another option to growers to either top-kill the crop immediately to secure the seed market when the PVY incidence is low or leave the tubers to develop further for table or processing purposes when incidence of PVY is high.

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