WERA89: Potato Virus and Virus-Like Disease Management

(Multistate Research Coordinating Committee and Information Exchange Group)

Status: Active

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SAES-422 Reports

Annual/Termination Reports:

[06/16/2022] [06/27/2023] [05/15/2024] [04/18/2025]

Date of Annual Report: 06/16/2022

Report Information

Annual Meeting Dates: 03/15/2022 - 03/16/2022
Period the Report Covers: 10/01/2021 - 09/30/2022

Participants

On-line:
David Douches
Hanu Pappu
Jason Ingram
Jonathan Whitworth
Joseph Coombs
Kylie Swisher Grimm
Max Feldman
Melanie Filiatrault
Steve Hystad
Tami Brown
Alan Westra
Prabu Gnanasekaran
Mathuresh Singh
Richard Manasseh
Hira Kamal
Kiwamu Tanaka
Gregory Elison
Brooke Babler
Rich Novy
Noelle Anglin In-person:
Adam Winchester
Alexander Karasev
Alice Pilgeram
Amy Charkowski
Andrew Houser
Brian Charlton
Erik Wenninger
Jen Rushton
John Mizicko
Julie Pasche
Kasia Duellman
Kenneth Frost
Kent Sather
Lynn Woodell
Mark Pavek
Nathan Gelles
Nina Zidack
Nora Olsen
Rabecka Hendricks
Renee Rioux
Sarah Hensley
Teresa Almeida
Vamsi Nalam
Vidyasagar Sathuvalli
Yuan Zeng

In-person:
Adam Winchester
Alexander Karasev
Alice Pilgeram
Amy Charkowski
Andrew Houser
Brian Charlton
Erik Wenninger
Jen Rushton
John Mizicko
Julie Pasche
Kasia Duellman
Kenneth Frost
Kent Sather
Lynn Woodell
Mark Pavek
Nathan Gelles
Nina Zidack
Nora Olsen
Rabecka Hendricks
Renee Rioux
Sarah Hensley
Teresa Almeida
Vamsi Nalam
Vidyasagar Sathuvalli
Yuan Zeng

Brief Summary of Minutes

Minutes Attachment:

WERA89 Minutes2022.docx

Accomplishments

The group continued to conduct research, extension programs and other outreach related to potato viruses and virus-like organisms. For example:   An SCRI grant, led by Dr. Alex Karasev at the University of Idaho, was awarded in fall of 2021. Numerous collaborators across multiple states have made progress in four areas and continue efforts to develop management solutions for necrotic viruses (PMTV and PVY) that infect potato. Work continues to understand the factors affecting the spread of PVY. Advances have been made in reducing virus levels in New Brunswick in recent years. Major trends in PVY spread were identified via amassing a very large data set of grower practices and other factors. Management decisions by individual growers play a large role, among other factors. Led by Dr. Mathuresh Singh, this effort may provide other regions with strategies to improve PVY management. Research conducted in Idaho and New York to determine the interaction between cultivar and PVY strain in both the foliage and tubers will aid in certification efforts. A poster detailing the results is publicly available by contacting Jonathan Whitworth. Dr. Hanu Pappu’s group is working on several aspects of PVY including virus-induced metabolic adjustments, PVY-coded NIa protein modulating the auxin-signaling pathway and disease development, and the roles of PMTV proteins using a PVX-based expression system. Advances in dormant tuber testing for PVY (potato virus Y) continue. However, the industry is not yet at the point of replacing seed-lot grow outs, particularly since dormant tuber testing cannot efficiently detect chemical injury and variety mix. Continued advances in tuber testing methods will shift the metric of a good test beyond what has always been the first hurdle of the “false negative rate” and how we plan for beyond that. Stakeholders have requested more information that could be collected using expanded dormant tuber tests to aid in farm decision making. SHERLOCK (specific high-sensitivity reporter unlocking) is being investigated for PVY detection. This method combines recombinase polymerase amplification (RPA) with a second by cleavage of a reporter probe by a Cas13 enzyme to reduce false negative results. Environmental sensors are being investigated to improve the ability to predict powdery scab. Sensors were placed in commercial potato fields across five states and environmental / crop data were correlated to disease incidence and severity. Principle component analysis was used on soil characteristics. Root gall formation was correlated to root susceptibility and initial pathogen density.

Publications

Combest, M.M., Moroz N., Rogan C., Tanaka K., Anderson J., Rakotondrafara A.M., and Goyer A. 2021. StPIP1, a predicted PAMP-induced peptide in potato, elicits plant defenses and is associated with disease symptom severity in a compatible interaction with potato virus Y. Journal of Experimental Botany (In Press) https://academic.oup.com/jxb/advance-article-abstract/doi/10.1093/jxb/erab078/6157931 Dahan, J., Cooper, W.R., Munyaneza, J., and Karasev, A.V. (2022) A new Bactericera cockerelli picorna-like virus identified in populations of potato psyllids. Archives of Virology 167: 177-182 (https://doi.org/10.1007/s00705-021-05281-x). Dahan, J., Wenninger, E.J., Thornton, M., Reyes-Corral, C.A., Olsen, N., and Karasev, A.V. (2021) Haplotyping the potato psyllid (Hemiptera: Triozidae), and the associated pathogenic bacterium ‘Candidatus Liberibacter solanacearum’ in non-crop alternative hosts in Southern Idaho. Environmental Entomology 50: 382–389 (<a href="https://doi.org/10.1093/ee/nvaa179">https://doi.org/10.1093/ee/nvaa179</a>). Elison, G.L., Novy, R.G. & Whitworth, J.L. Russet Potato Breeding Clones with Extreme Resistance to Potato Virus Y Conferred by Rychc as well as Resistance to Late Blight and Cold-Induced Sweetening. Am. J. Potato Res. 98, 411–419 (2021). <a href="https://doi.org/10.1007/s12230-021-09852-1">https://doi.org/10.1007/s12230-021-09852-1</a> Goyer A (2021) From tolerant to sensitive: how a small peptide produced by potato plants determines the fate of potato-PVY interaction. Potato Progress. Vol. XXI, Number 4. Mondal, S., Ghanim, M., Roberts, A., and Gray, S. M. 2021. Different potato virus Y strains frequently co- localize in single epidermal leaf cells and in the aphid stylet. Journal of General Virology. 102:001576 DOI 10.1099/jgv.0.001576 Mondal, S., Wintermantel, W. M., and Gray, S. 2022. Infection dynamics of potato virus Y isolate combinations in three potato cultivars. Plant dis. https://doi.org/10.1094/PDIS-09-21-1980-RE Olsen, N. and A. Karasev. 2021. Going viral- tackling the problem of evolving viruses. Potato Grower Magazine. May 50(5):36-37. Olsen, N., A. Karasev, J. Miller and J. Whitworth. 2022. Everything you wanted to know about potato viruses, but were afraid to ask. Idaho Potato Conference. Pocatello, ID. January 19, 2022. Olsen, N. 2021. Effective practices to manage Black Spot Bruise and PVY in potatoes and the proper use of products for good storage management CHS Bingham Cooperative Grower Meeting (virtual). March 4, 2021. Olsen, N. and J. Miller. 2021. Powdery scab and potato mop-top virus (PMTV) management. Miller Research Potato Pest Management seminar (virtual). February 18, 2021. Pandey, B., Mallik, I., Arjarquah, A., Shahoveisi, F., and Pasche, J. S. 2022. Assessing optimum timing for detecting Potato mop-top virus (PMTV) in potato seed tubers. Plant Dis. (abstract) in press. Reyes-Corral, C., Cooper, W.R., Horton, D., Miliczky, E., Riebe, J., Waters, T., Wildung, M., and Karasev, A.V. (2021) Association of Bactericera cockerelli (Hemiptera: Triozidae) with the perennial weed Physalis longifolia (Solanales: Solanaceae) in the potato-growing regions of western Idaho. Environmental Entomology 50: 1416-1424 Rodriguez-Rodriguez, M., Quintero-Ferrer, A., Green, K.J., Robles-Hernandez, L., Gonzalez-Franco, A.C., and Karasev, A.V. (2021) Molecular and biological characterization of recombinant isolates of Potato virus Y circulating in potato fields in Mexico. Plant Disease 105: 2688-2696 (https://doi.org/10.1094/PDIS-10-20-2215-RE). Ross, B.T., Zidack, N., and Flenniken, M.L., Extreme Resistance to Viruses in Potato and Soybean, (2021), Frontiers in Plant Science, https://doi.org/10.3389/fpls.2021.658981. Ross, B.T., Zidack, N., McDonald, R., and Flenniken, M.L. 2022. Transcriptome and Small RNA Profiling of Potato Virus Y Infected Potato Cultivars, Including Systemically Infected Russet Burbank. Viruses. 14(3), 523; https://doi.org/10.3390/v14030523 Tran, L., K. Green, M. Rodriguez-Rodriquez, G. Orellana, C. Funke, O. Nikolaeva, A. Quintero-Ferrer, M. Chikh-Ali, L. Woodell, N. Olsen and A. Karasev. 2021 (online Oct 2021). Prevalence of recombinant strains of potato virus Y in seed potato planted in Idaho and Washington states between 2011 and 2021. Plant Disease. https://doi.org/10.1094/PDIS-08-21-1852-SR. Vales, M.I., Scheuring, D.C., Koym, J.W. et al. Vanguard Russet: A Fresh Market Potato Cultivar with Medium-Early Maturity and Long Dormancy. Am. J. Potato Res. (2022). <a href="https://doi.org/10.1007/s12230-022-09877-0">https://doi.org/10.1007/s12230-022-09877-0</a> Whitworth, J.L., Gray, S.M., Ingram, J.T. et al. Foliar and Tuber Symptoms of U.S. Potato Varieties to Multiple Strains and Isolates of Potato virus Y. Am. J. Potato Res. 98, 93–103 (2021). <a href="https://doi.org/10.1007/s12230-020-09820-1">https://doi.org/10.1007/s12230-020-09820-1</a> Woodell, L. and N. Olsen. 2021. The impact of Tobacco Rattle Virus on Potato Quality at Harvest and in Storage. American Journal of Potato Research (abstract). In press. Zhang, C., Zarka, K.A., Zarka, D.G. et al. Expression of the Tomato pot-1 Gene Confers Potato Virus Y (PVY) Resistance in Susceptible Potato Varieties. Am. J. Potato Res. 98, 42–50 (2021). https://doi.org/10.1007/s12230-020-09815-y

Impact Statements

Presentations on current research were provided by attendees. Over-arching categories for updates included virus-like organisms, diagnostics, TRV/PMTV, PVY biology, PVY management, and other topics. These updates generated good discussion and showed progress in areas such as dormant tuber testing, sampling strategies, PVY strain composition and spread, PVY management with mineral oils and biologicals, tools to breed for resistance, variety reactions to PMTV, powdery scab/PMTV prediction modeling, and others.

Date of Annual Report: 06/27/2023

Report Information

Annual Meeting Dates: 03/16/2023 - 03/17/2023
Period the Report Covers: 01/01/2022 - 12/31/2022

Participants

Attendee Institution
Adam Winchester North Dakota State University Seed Certification
Alex Karasev University of Idaho
Alex Scalzo USDA-ARS
Alice Pilgrim Montana State
Amer Fayad USDA-ARS
Amy Charkowski Colorado State University
Andrew Houser Colorado State University Potato Seed Certification
Andrew Plant Maine Seeed Certification
Aymeric Goyer Oregon State University
Brooke Babler Wisconsin Seed Certification
Chakradhar Mattupalli Washington State University
Chris McIntosh University of Idaho
Emma Tracy Seed Certification Montana
Erik Wenninger University of Idaho
Esra Yilmaz Colorado State University
Jennifer Dillinger Nebraska Seed Certification
Jennifer Rushton Colorado State University
Jessica Chitwood-Brown Colorado State University
Joe Coombs Michigan State
Jonathan Whitworth USDA-ARS
Josie Spurgeion Wisconsin Seed Certification
Julie Pasche North Dakota State University
Kasia Duellman University of Idaho
Keith Schunetz Agdia
Kelie Yoho University of Idaho
Ken Frost Oregon State University
Kent Sather North Dakota State University Seed Certification
Kylie Swisher-Grimm USDA-ARS
Lisa Tran University of Idaho
Mahbuba Fatema Colorado State University
Mark Pavek Washington State University
Mathuresh Singh Seed Certification New Brunswick
Max Feldman USDA-ARS
Melissa Bertram University of Idaho
Michelle Leckler Colorado State University Potato Seed Certification
Mohamad Chickh-Ali Colorado State University
Nathan Gelles University of Idaho
Presely Mosher North Dakota State University
Rabecka Hendricks University of Idaho
Russel Groves University of Wisconsin
Tara Gauthier Agdia
Teresa Almeida Colorado State University Potato Seed Certification
Vidyasagar Sathuvalli Oregon State University
Walter DeJong Cornell University

Brief Summary of Minutes

Minutes Attachment:

WERA Meeting Minutes 031623-Report.docx

Accomplishments

Publications

Journal Publications Chikh-Ali, M. and Karasev, A.V. 2023. Chapter 11. Virus diseases of potato and their control. In: Potato Production Worldwide (Eds., Caliskan, M.E., Bakhsh, A., and Jabran, K.), Elsevier, Inc.: London, San Diego, Cambridge, Oxford; pp. 199-211.   Ding, P., Chen, D., Feng, H., Li, J., Cao, H., Muning, T., Li, J., Hao, X., Han, P., Karasev, A.V., and Feng, X. 2022. Prevalence and strain composition of potato virus Y circulating in potato fields in China’s north-central province of Shanxi. Plant Disease 106: 1434–1445 (<a href="https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1094%2FPDIS-09-21-1950-RE&data=05%7C01%7C%7C52b664a18fe3469760c908db68372135%7Ced5b36e701ee4ebc867ee03cfa0d4697%7C0%7C0%7C638218358214345045%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=do3T5e17HDLPLwuMSQd3szsxn%2BJD6ILhD8CE6ztPR9I%3D&reserved=0">https://doi.org/10.1094/PDIS-09-21-1950-RE</a>).   Duellman, K.M.*, Whitworth, J., Lent, M.A., Bertram, M.C., and Randall, J.C. Published online ahead of print 19 June 2022. Mechanical transmission of Potato virus Y by seed cutting is not a contributing factor to increased virus in field production. Plant Health Progress. <a href="https://doi.org/10.1094/PHP-02-22-0011-RS">https://doi.org/10.1094/PHP-02-22-0011-RS</a> (1, 2, 3, 4, 5, 6)    Duellman, K., Woodhall, J., Karasev, A.V., Olsen, N., and Whitworth, J.L. 2022. Potato mop-top virus: biology and disease management. University of Idaho Extension Bulletin 1017: June 2022; 5pp.    Gelles, N., Olsen, N., Thornton, M., Karasev, A., Hendricks, R., and Woodell, L. 2023. Novel methods to induce sprouting in dormant potato tubers. Abstracts of the 106th Annual Meeting of The Potato Association of America. American Journal of Potato Research 100 (2): 121.   Hendricks, R.L., N. Olsen, M. Thornton and P. Hatzenbuehler. 2022. Susceptibility of potato cultivars to blackspot and shatter bruise at three impact heights. American Journal of Potato Research 99:358-368.   Kud, J., Dahan, J., Orellana, G.E., Dandurand, L.-M., and Karasev, A.V. 2022. A novel rhabdovirus associated with the Idaho population of potato cyst nematode Globodera pallida. Viruses 14 (12): 2718 (<a href="https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.3390%2Fv14122718&data=05%7C01%7C%7C52b664a18fe3469760c908db68372135%7Ced5b36e701ee4ebc867ee03cfa0d4697%7C0%7C0%7C638218358214345045%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CnKjVJGu860T1U8fu4p0YdId4jdylSwwH2u%2BbJTiBkc%3D&reserved=0">https://doi.org/10.3390/v14122718</a>).   Manasseh, R., Berim, A., Kappagantu, M., Moyo, L., Gang, D. R., & Pappu, H. R. (2023). Pathogen-triggered metabolic adjustments to potato virus Y infection in potato. Frontiers in plant science, 13, 1031629. <a href="https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.3389%2Ffpls.2022.1031629&data=05%7C01%7C%7Cccdb8cf63f294889901008db67d660a4%7Ced5b36e701ee4ebc867ee03cfa0d4697%7C0%7C0%7C638217942678801647%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=WRvDVP26XQP%2FnqqdE13gyRxPWQFENlHFa%2BuKMQ1Ewh4%3D&reserved=0">https://doi.org/10.3389/fpls.2022.1031629</a>   Mora, V., M. Ramasamy, M. B. Damaj, S. Irigoyen, V. Ancona, C. A. Avila, M. I. Vales, F. Ibanez, and K. K. Mandadi. 2022. Identification and characterization of new sources of zebra chip disease resistance among wild Solanum species. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2022.857493.   Novy, R.G., J.L. Whitworth, J.C. Stark, R.R. Spear, B.L. Schneider, M.J. Pavek, N.R. Knowles, L.O. Knowles, B.A. Charlton, V. Sathuvalli, S. Yilma, C.R. Brown, T.L. Brandt, M. Thornton, and N. Olsen. 2021. La Belle Russet: an early maturing, dual-purpose variety having a high percentage of marketable yield, long tuber dormancy, and a reduced incidence of sugar ends. American Journal of Potato Research 98:395-410.   Pandey, J, D.C. Scheuring, J.W. Koym, and M.I. Vales. 2022. Genomic Regions Associated with Tuber Traits in Tetraploid Potatoes and Identification of Superior Clones for Breeding Purposes. Frontiers in Plant Science. https://doi.org/10.3389/fpls.2022.952263.   Tran, L.T., Green, K.J., Rodriguez-Rodriguez, M., Orellana, G.E., Funke, C.N., Nikolaeva, O.V., Quintero-Ferrer, A., Chikh-Ali, M., Woodell, L., Olsen, N., and Karasev, A.V. 2022. Prevalence of recombinant strains of potato virus Y in seed potato planted in Idaho and Washington states between 2011 and 2021. Plant Disease 106: 810-817 (<a href="https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1094%2FPDIS-08-21-1852-SR&data=05%7C01%7C%7C52b664a18fe3469760c908db68372135%7Ced5b36e701ee4ebc867ee03cfa0d4697%7C0%7C0%7C638218358214345045%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=S6zVp95KiWXGa0DqLKoeF7zSliCHVigqHpnhg2WA2bQ%3D&reserved=0">https://doi.org/10.1094/PDIS-08-21-1852-SR</a>).   Toinga-Villafuerte, S., M.I. Vales, J.M. Awika and K.S. Rathore. 2022. CRISPR/Cas9-mediated mutagenesis of the granule-bound starch synthase gene in the potato variety Yukon Gold to obtain amylose-free starch in tubers. International Journal of Molecular Sciences. 23: 4640 DOI: 10.3390/ijms23094640.   Toinga-Villafuerte, S., M.R. Janga, M.I. Vales, and K.S. Rathore. 2022. Green fluorescent protein gene as a tool to examine the efficacy of Agrobacterium delivered CRISPR/Cas9 reagents to generate targeted mutations in the potato genome. Plant Cell, Tissue and Organ Culture. Plant Cell, Tissue and Organ Culture (PCTOC). https://doi.org/10.1007/s11240-022-02310-8.   Vales, M.I., D.C. Scheuring, J.W. Koym, D.G. Holm, S.Y.C. Essah, R.G. Wilson, J.K. Sidhu, R.G. Novy, J.L. Whitworth, J.C. Stark, R.R. Spear, V. Sathuvalli, C.C. Shock, B.A. Charlton, S. Yilma, N.R. Knowles, M.J. Pavek, C.R. Brown, D.A. Navarre, M. Feldman, C.M. Long, and J.C. Miller, Jr. 2022. Vanguard Russet: A Fresh Market Potato Cultivar with Medium-Early Maturity and Long Dormancy. American Journal of Potato Research. 99: 258–267. Hoopes, G., X. Meng, J.P. Hamilton, S.R. Achakkagari, F. de A. Freitas Guesdes. M.E. Bolger, J.J. Coombs, D. Esselink, N.R. Kaiser, L. Kodde, M. Kyriakidou, B. Lavrijssen, N. van Lieshout, R. Shereda, H.K. Tuttle, B. Vaillancourt, J.C. Wood, J. M. de Boer, P.M. Bourke, D. Douches, H.J. van Eck, D. Ellis, M.J. Feldman, K.M. Gardner, J. C.P. Hopman, J. Jiang, W.S. de Jong, J.C. Kuhl, R.G. Novy, S. Oome, V. Sathuvalli, E.H. Tan, R.A. Ursem, M.I. Vales, K. Vining, R. G.F. Visser, J. Vossen, G.C. Yencho, N.L. Anglin, C.W.B. Bachem, J.B. Endelman, L.M. Shannon, M. Strömvik, H.H. Tai, B. Usadel, C. Robin Buell, R. Finkers. 2022. Phased, chromosome-scale genome assemblies of tetraploid potato reveals a complex genome, transcriptome, and proteome landscape that underpin phenotypic diversity. Molecular Plant 15: 520-536.   Conference Abstracts da Silva, J., N. Gracia, I. Vales, S. Gautam, and K. Mandadi. Applications of bioreactors to plant breeding. 76th Annual Meeting of the Subtropical Agriculture and Environments Society. February 11, 2022, Weslaco, TX. (oral presentation)   Duellman, K.M., Lent, M.A., Liu, C., McKinney, L.F., and Wenninger, E.J. 2023. Timing of in-season plant-to-plant spread of Potato virus Y in potato in Idaho, United States. 12th International Congress of Plant Pathology, Lyon, France, August 20-25, 2023 (poster).   Gelles, N., Olsen, N., Thornton, M., Karasev, A., Hendricks, R., and Woodell, L. 2023. Novel methods to induce sprouting in dormant potato tubers. Abstracts of the 106th Annual Meeting of The Potato Association of America. American Journal of Potato Research 100 (2): 121.   Ifeduba, A.M., S. Zhen, and M.I. Vales. Global warming-ready potatoes: Understanding heat tolerance in potato clones from the Texas A&M breeding program. National Association of Plant Breeders 2022 Annual Meeting. August 8-11, 2022, Ames, IA. Poster.   Jiao, A., S. Gautam, J. Pandey, D.C. Scheuring, J.W. Koym, M.I. Vales. 2022. Genome-wide association studies for tuber dormancy in tetraploid potatoes. American Society for Horticultural Sciences. 2022 Annual Conference. Chicago, IL, July 30 - August 3, 2022. Poster.   Jiao, A., S. Gautam, J. Pandey, D.C. Scheuring, J.W.  Koym, M.I. Vales. Investigating the genetic background of potato tuber dormancy. Plant and Animal Genome Conference XXIX. January 8-12, 2022. Online. Digital poster.   Gautam S., J. Pandey, D.C. Scheuring, J.W. Koym, and M.I. Vales. Genome-wide association study on potato tuber defects under heat stress. Plant and Animal Genome Conference XXIX. January 8-12, 2022. Online. Digital poster.   Pandey, J., D.C. Scheuring, J.W. Koym, and M.I. Vales. Genomic prediction of chipping quality in tetraploid potato. Plant and Animal Genome Conference XXIX. January 8-12, 2022. Online. Digital poster.   Tran, L.T., Green, K.J., Rodriguez-Rodriguez, M., Orellana, G.E., Funke, C.N., Nikolaeva, O.V., Quintero-Ferrer, A., Chikh-Ali, M., Woodell, L., Olsen, N., and Karasev, A.V. 2023. Changes in prevalence of potato virus Y strains circulating in potato in the Pacific Northwest, 2011-2021. Abstracts of the 106th Annual Meeting of The Potato Association of America. American Journal of Potato Research 100 (2): 128.   Press Duellman, K. 2022. Border crops for Potato virus Y management in seed potato production. Potato Grower, December 2022, pp. 24-25.   Gelles, N., Olsen, N., Thornton, M., and Karasev, A. 2022. Early detection. New methods to break tuber dormancy to facilitate virus testing of seed potato. Potato Country, December 2022; pp. 20-22.   Olsen, N. Karasev, A., and Whitworth, J. 2022. Changing faces. How the industry can adjust to evolving PVY strains. Potato Grower Magazine, April 2022; pp. 30-31.   Olsen, N., Whitworth, J. and Karasev, A. 2022. New kids on the block. Success in PVY-resistant varieties. Potato Grower Magazine, May 2022; pp. 32-33.

Impact Statements

The WERA-89 meeting allows for stronger collaboration among certification programs and researchers to tailor future research projects to address problems currently being faced in potato production across the US.

Date of Annual Report: 05/15/2024

Report Information

Annual Meeting Dates: 03/12/2024 - 03/13/2024
Period the Report Covers: 01/01/2023 - 12/31/2023

Participants

In-person attendees
First name Last name Affiliation
Noelle Anglin USDA ARS
Alex Karasev University of Idaho
Nora Olsen University of Idaho
Nina Zidack Montana Seed Certification
Sagar Sathuvalli Oregon State University
Mark Pavek Washington State University
Rebecka Hendricks University of Idaho
Walter DeJong Cornell University
Jonathan Whitworth USDA ARS
Ana Cristina Fulladolsa Colorado State University
Jaime Willbur Michigan State University
Alan Westra ICIA
Rhett Spear University of Idaho
Keith Schultz Agdia
Heidi Falzon Agdia
Eric Wenninger University of Idaho
Chris McIntosh University of Idaho
Pragati Dahal University of Idaho
Cole Lubinski Wisconsin Seed Potato Certification
Alex Scalzo University of Idaho
Kelie Yoho University of Idaho
Alice Pilgeram Montana State University
Josie Spurgeon Wisconsin Seed Potato Certification
John Onditi USDA ARS/ORISE
Melanie Filiatrault USDA ARS
Adam Winchester North Dakota SSD
Andrew Houser Colorado Potato Certification Service
Sarah Hensley Colorado Potato Certification Service
Chakradhar Mattupalli Washington State University
Julie Pasche North Dakota State University
Brooke Babler Wisconsin Seed Potato Certification

Zoom attendees
First name Last name Affiliation
Amer Fayad USDA ARS
Aymeric Goyer Oregon State University
Benita Matheson Washington Seed Potato Association
Tami Brown Oregon State University
Caroline Gray Colorado State University
Eric Byre Minnesota Dept. of Agriculture
Eric Hitchcock Maine Seed Potato Certification
Jenn Dillinger Nebraska Potatoes
Joseph Coombs Michigan State University
Ken Frost Oregon State University
Kiwamu Tanaka Washington State University
Kylie Swisher Grimm USDA ARS
Lisa Tran ICIA
Mathuresh Singh Agri-Food Canada Potato Research Centre
Max Feldman USDA ARS
Teresa Almeida Colorado Potato Certification Service
Vamsi Nalam Colorado State University
Zachariah Hansen USDA ARS
Jason Ingram Cornell University
Amy Charkowski Colorado State University
Jacob Schow Montana Seed Certification
Damen Kurzer Michigan Seed Potato Association
Melinda Lent University of Idaho
Melissa Bertram University of Idaho
Mio Sato-Cruz Michigan State University
Hanu Pappu Washington State University
Karkee Manoj Washington State University
Jeffrey Endelman UW-Madison

Brief Summary of Minutes

Accomplishments

<ul> <li>The potato virus and virus-like research and extension community continued to make advancements towards the management of economically important diseases caused by these organisms. Examples include:</li> <li>A Specialty Crop Research Initiative (SCRI) was awarded in 2021. The SCRI titled Development of sustainable system-based management strategies for two vector-borne, tuber necrotic viruses in potato is led by Alexander Karasev (U of ID). Many members of the WERA89 are involved in the four specific objectives outlined in the SCRI. Discussions were started on the next steps needed to advance research and extension efforts in this area.</li> <li>The renewal for WERA89 will be submitted during the next year. Discussions were initiated concerning responsibilities for completion of the resubmission.</li> <li>Validation studies for direct tuber testing of PVY is continuing in states such as Colorado, Wisconsin, and Montana.</li> <li>Mail-away PVY test project conducted with over 40,000 tubers yielded results comparable to those obtained from winter grow outs. Efforts are in progress to build an automated tuber sampling robot that will ease tedious sampling collection process involved with direct tuber testing.</li> <li>Role of dogs in detecting PVY from tubers was found to yield inconsistent results in studies conducted at Montana and Colorado.</li> <li>Modifying irrigation to manage powdery scab and/or PMTV tuber symptoms was not effective and resulted in significant yield and quality reductions.</li> <li>Field studies from Idaho showed that seedborne PVY can impact yield, but the response is cultivar dependent and physiological age of the seed.</li> <li>Ten peer reviewed papers, eight articles in trade journals, and six abstracts focusing on necrotic potato viruses were published between Mar 2023-24.</li> </ul>

Publications

Peer-reviewed Publications: Bvindi, C. N., Howe, K., Wang, Y., Mullen, R. T., Rogan, C. J., Anderson, J., Goyer, A. J. 2023. Potato non-specific lipid transfer protein StnsLTPI.33 is associated with the production of reactive oxygen species, plant growth, and susceptibility to Alternaria solani. Plants 12:3129. <a href="https://doi.org/10.3390/plants12173129">https://doi.org/10.3390/plants12173129</a> Dahan, J., Pedroni, M.J., Thompson, B.D., Chikh-Ali, M., Dandurand, L.-M., Kuhl, J.C., and Karasev, A.V. 2023. First report of tomato chlorotic dwarf viroid infecting litchi tomato (Solanum sisymbriifolium). Plant Disease 107: 2564. <a href="https://doi.org/10.1094/PDIS-03-23-0422-PDN">https://doi.org/10.1094/PDIS-03-23-0422-PDN</a>    Dahan, J., Orellana, G.E., Wald, K.B., Wenninger, E.J., Cooper, W.R., and Karasev, A.V. 2024. Bactericera cockerelli picorna-like virus and three new viruses found circulating in populations of potato/tomato psyllids (Bactericera cockerelli). Viruses 16: 415 <a href="https://doi.org/10.3390/v16030415">https://doi.org/10.3390/v16030415</a> Daniel, J., and Chikh-Ali, M, 2024. Dynamics of potato virus Y infection pressure and strain composition in the San Luis Valley, Colorado. Plant Disease (Accepted Jan 2024. In Press). Gnanasekaran, P., Zhai, Y., Kamal, H., Smertenko, A., and Pappu, H.R. 2023. A plant virus protein, NIa-pro promotes disease development via by modulating Indole-3-acetic acid amido synthetase. Frontiers in Plant Science. 14:1112821. <a href="https://doi.org/10.3389/fpls.2023.1112821">https://doi.org/10.3389/fpls.2023.1112821</a> Goyer, A. J., Bvindi, C. N. 2023. Overexpression of VQ motif-containing gene does not affect infection rates of potato with potato virus Y. American Journal of Potato Research 100: 233–239. <a href="https://doi.org/10.1007/s12230-023-09913-7">https://doi.org/10.1007/s12230-023-09913-7</a> Goraya, M., Yan, G., Whitworth, J., and Swisher Grimm, K.D. 2023 Advancing nematode identification on potato: An isothermal recombinase polymerase amplification assay for stubby root nematode, Paratrichodorus allius. American Journal of Potato Research 101:52-64. <a href="https://doi.org/10.1007/s12230-023-09940-4">https://doi.org/10.1007/s12230-023-09940-4</a> Kamal, H., V. Lynch-Holmes, H.R. Pappu, and Tanaka, K. 2024. Starch plays a key role in sporosorus formation by the powdery scab pathogen Spongospora subterranea. Phytopathology 114:568-579. <a href="https://doi.org/10.1094/PHYTO-07-23-0224-R">https://doi.org/10.1094/PHYTO-07-23-0224-R</a> Rodriguez-Rodriguez, M., Chikh-Ali, M., Feng, X., and Karasev, A.V. (2024). Genome sequences of six recombinant variants of potato virus Y identified in North American potato cultivars grown in China. Microbiology Resource Announcements 12: e00512-23 <a href="https://doi.org/10.1128/MRA.00512-23">https://doi.org/10.1128/MRA.00512-23</a> Wenninger, E.J. and Rashed, A. 2024. Biology, ecology, and management of the potato psyllid, Bactericera cockerelli (Hemiptera: Triozidae), and zebra chip disease in potato. Annual Review of Entomology 69:139–157. <a href="https://doi.org/10.1146/annurev-ento-020123-014734">https://doi.org/10.1146/annurev-ento-020123-014734</a>   Abstracts: Arjarquah, A., Singh, J., Zitnick-Anderson, K., Pandey, B., Gill, U., and Pasche, J.S. 2023. A draft reference genome of Spongospora subterranea from North America. (Abst.) Amer J Potato Res. (In Press) Dahan, J., Pedroni, M.J., Thompson, B.D., Chikh-Ali, M., Dandurand, L.-M., Kuhl, J.C., and Karasev, A.V. 2023. An asymptomatic infection of tomato chlorotic dwarf viroid in litchi tomato (Solanum sisymbriifolium). (Abstr.) Phytopathology 113: S3.197. <a href="https://doi.org/10.1094/PHYTO-113-11-S3.1">https://doi.org/10.1094/PHYTO-113-11-S3.1</a> Gelles, N., N. Olsen, M. Thornton, A. Karasev, R. Hendricks, and Woodell, L. 2023. Alternative methods to initiate sprouting in potatoes to facilitate PVY testing (abstract). American Journal of Potato Research 100:115-134. Ingram, J.T., Mattupalli, C., Charkowski, A.O., Karasev, A.V., and Filiatrault, M.J. 2023. A grower-supported mail-away dormant potato tuber test for molecular detection of potato virus Y, and two other tuber necrotic viruses. (Abstr.) Phytopathology 113: S3.35. <a href="https://doi.org/10.1094/PHYTO-113-11-S3.1">https://doi.org/10.1094/PHYTO-113-11-S3.1</a> Kud, J., Dahan, J., Orellana, G.E., Dandurand, L.-M., and Karasev, A.V. 2023. A novel rhabdovirus associated with the Idaho population of the potato cyst nematode Globodera pallida. (Abstr.) Phytopathology 113: S3.21. <a href="https://doi.org/10.1094/PHYTO-113-11-S3.1">https://doi.org/10.1094/PHYTO-113-11-S3.1</a> Qin, R., Goyer, A. J., and Torabian, S. 2023 Effect of potassium fertilization on the nutritional contents of potato tubers. ASA, CSSA, SSSA International Annual Meeting <a href="https://scisoc.confex.com/scisoc/2023am/meetingapp.cgi/Paper/149926">https://scisoc.confex.com/scisoc/2023am/meetingapp.cgi/Paper/149926</a>    Thesis: Gelles, N. A. 2023. Altering potato tuber physiology to promote dormancy break and implications of PVY in seed certification. Master’s Thesis, University of Idaho.   Trade Publications: Duellman, K., and Wenninger, E. 2023. Tracking Potato virus Y. Potato Grower 52(13):28-29. Duellman, K., Wenninger E., and Woodhall, J. 2023. Monitoring vectors of potato pathogens to assess risk. Potato Grower 52(11):24-25. Grimm, K. S., Quick, R., Cimrhakl, L., Feldman, M., and Pavek, M. 2024. Improving our understanding of potato mop-top virus in the northwest U.S. Potato Grower 53(1):33-38. Karasev, A., and Olsen, N. 2023. Potato virus initiative developing direct tuber testing alternatives. Potato Grower 52(4):22-23. Miller, J. N. Olsen, and J. Woodhall. 2023. Can irrigation management reduce powdery scab or PMTV symptoms? Potato Progress 23(6). Schreiber, A., A. Jensen, S. Rondon, E. Wenninger, S. Reitz, and Waters, T. 2023. Integrated pest management guidelines for insects and mites in Idaho, Oregon and Washington potatoes. <a href="https://www.nwpotatoresearch.com/item/pest-management-options">https://www.nwpotatoresearch.com/item/pest-management-options</a> Zidack, N. 2023. Seed potato workshop proves highly valuable. Potato Grower 52(6):36.37. Zidack, N. 2024. Why Hawaii for seed growout? Potato Grower 53(1):90-91.         Presentations: Berrian, T., Clarke, C., and Goyer, A. J. 2023. Annual Meeting of the Potato Association of America, "Testing thiamin as an immunity inducer against diseases of potato," Charlottetown, Prince Edward Island, Canada. July 23, 2023. Duellman, K.M., Lent, M.A., Liu, C., McKinney, L.F., and Wenninger, E.J. 2023. Timing of in-season plant-to-plant spread of Potato virus Y in potato in Idaho, United States. 12th International Congress of Plant Pathology, Lyon, France, August 20-25, 2023 (poster). Gelles, N. and Olsen, N. 2023. Breaking tuber dormancy to support the seed certification process. WERA89 Meeting. Denver, CO, March 16, 2023. Gelles, N. and Olsen, N. 2023. Use of smoke in seed certification to induce sprouting. Nebraska Potato Council Meeting (virtual). January 27, 2023. Goyer, A. J., Bvindi, C., Wang, Y., and Mullen, R. T. 2023. International Society of Plant Microbe Molecular Interactions, "Functional characterization of a member of the non-specific lipid transfer protein family in potato," Providence, Rhode Island. July 17, 2023. Goyer, A. J., Combest, M., and Bvindi, C. 2023. Annual Meeting of the Potato Association of America, "Inferring gene functions from transcriptomic data: a precautionary tale," Charlottetown, Prince Edward Island, Canada. July 23, 2023. Hendricks, R. and Olsen, N. 2023. PVY and Yield- How much of an impact. WERA89 Meeting. Denver, CO, March 16, 2023. Hendrick, R. and Olsen, N. 2023. Progress on sprout promotion for direct tuber testing and the WGO, PVY impact on yield, seed size and PVY relationship, and extension activities. Potato Virus Initiative SCRI meeting. Denver, CO, March 17, 2023. Olsen, N., A. Karasev, E. Wenninger, K. Duellman, and Whitworth, J. 2024. PVY and PMTV and what we have learned from the SCRI project. Idaho Potato Conference. Pocatello, ID January 18, 2024. Olsen, N. R. Hendricks, and Karasev, A. 2023. Highlights from the Potato Virus Initiative. Idaho Association of Plant Protection Annual Meeting. Rupert, ID. November 2, 2023. Olsen, N. 2023. Potato Production and Storage Research: Emphasis on testing for PVY. Snake River Weed Management Tour and Field Day. Kimberly, ID, June 28, 2023. Olsen, N. and Karasev, A. 2023. Potato Virus Initiative: developing solutions update and discussion. Washington State University Potato Field Day. Othello, WA, June 22, 2023. Olsen, N. 2023. Diagnosing potato diseases and management options. Shoshone-Bannock Tribes ARM 29th Annual Grower Meeting. Fort Hall, ID, March 2, 2023. Olsen, N. 2023. Seed potatoes: stem numbers, seed size and PVY. Bingham Ag Services Annual Grower Meeting. Blackfoot, ID, March 1, 2023. Olsen, N. and Miller, J. 2023. Interactive storage disease diagnosis workshop. Idaho Potato Conference. Pocatello, ID January 18, 2023. Qin, R., Goyer, A. J., and Torabian, S. 2023. ASA, CSSA, SSSA International Annual Meeting, "Effect of potassium fertilization on the nutritional contents of potato tubers," St Louis, Missouri. October 31, 2023.

Impact Statements

WERA89 continued to foster a collaborative platform for both seed potato certification agencies and potato researchers to discuss topics related to current state, challenges and prospects in seed certification; pest management; breeding innovations; diagnostic testing and optimization capabilities; and improving our overall understanding of necrotic viruses of potato.

Date of Annual Report: 04/18/2025

Report Information

Annual Meeting Dates: 03/11/2025 - 03/12/2025
Period the Report Covers: 03/10/2025 - 03/11/2025

Participants

Brooke Babler
Chakradhar Mattupalli
Jaime Willbur
Heidi Falzon
Josie Spurgeon
Sarah deVeer
Cole Lubinski
Nina Zidack
Andrew Houser
Teresa Almeida
Michelle Leckler
Jack Meevwsen
Zach Holden
Alice Pilgeram
Walter DeJong
Pia Spychalla
Mark Pavek
Alan Westra
Adam Winchester
Damen Kurzer
Aritra Roy Choudhury
Julie Pasche
Rachel Johnston
Rabecka Hendricks
Nora Olsen
Alex Karazev
Erik Wenninger
Chris McIntosh
Tami Brown
Mohamad Chikh-Ali

New in-person Day 2:
Pragati Dahal
Zoom: Joseph Coombs MSU, Benita Matheson WSDA, Rachel Selstedt NDSU, Melanie Filiatrault, Lisa Piche, Robert Alvarez U of MN, Noelle Anglin USDA, Aymeric Goyer, Beth Niebaum, Caroline Gray, Carolyn Keller, Dallas Domingues, Dipinte Gupta, Jenn Dillinger PCAN, John Hammel, John Onditi, Jonathan Whitworth USDA ARS ID, Kylie Swisher Grimm, Max Feldman USDA ARS WA, Megan, Melindab, Melissa Bertram, Muhammad Azmat Ullah Khan, Noelle Anglin, Rachel Selstedt, Rhett Spear, Sagar, Stephanie, Carolyn Keller, Meret B, Amy Charkowski

Brief Summary of Minutes

Meeting Minutes

8:00 am Call to Order (start 8:02 am)

Introduction

2024 Minutes approval (motion to approve Alex Karasev, seconded Nina Zidack)

2025 Agenda discussion/approval (motion to approve Julie Pasche, seconded Andrew Houser)

Other announcements: Lunch location, SCRI meeting tomorrow in same room

8:15 am State Certification Reports

Tami Brown - Oregon State Seed Potato Certification (8:11-8:23)

Certified 3,364 acres with 112 lots, some deferred for nematode concerns, commercial use, or size exemptions. The growing areas are located in four counties: Gilliam, Union, Jefferson, and Klamath. Certified production has been ongoing since 2017, with approximately 3,300 acres under certification. The primary varieties grown are Clearwater Russet and Lamoka, mostly FY2 and FY3, with one grower producing FY1. DTT was conducted on 14 lots, with 12 testing negative; the protocol included a two-week warm incubation (~85°F) followed by lab testing. Greenhouse growth post-coring was reportedly affected. Among 19 samples, PVY strains detected were predominantly NTN and N-Wi, with one N:O. Concerns were raised about the feasibility of on-farm coring in Oregon.

Alan Westra - Idaho Crop Improvement Association (8:25-8:39)

Between 2008 and 2024, approximately 32,000 acres of potatoes were planted, exceeding current needs, prompting some dumping this year, with an ideal target closer to 30,000 acres. Rejection rates were low at 0.10%, mostly due to paperwork issues rather than virus presence. In 2024, monitoring for leaf roll and mosaic showed 7.9% of seed lots testing positive – slightly higher than the 7.6% in 2008 – with 59 positive and 750 negative samples. Blackleg incidence was low at 0.89%, increasing to 2.58% on second inspection, with rates ranging from 0.01% to 0.03%. Since 2014, over 4.5 million cores have been tested for bacterial ring rot (BRR) using the core and soak method. However, growers have shown little interest in on-farm tuber coring due to testing fatigue with FTA cards. Winter growouts have been poor, with slow and uneven emergence – only 7% of potatoes picked and tested by January 1 compared to the usual 30% – and overall stands averaging 79% with a 10-year average of 78%. Post-harvest test (PHT) PVY results in 2024 showed about 50% certification eligibility, with 30% of samples at 0% PVY, another 30% under 1%, and an overall PVY mean of 3%. Discrepancies between leaf and retests pointed to possible late-season PVY infections.

Nina Zidack - Montana Potato Seed Certification Program (9:26-9:45)

Poor emergence in Hawaii due to dry soil conditions, despite irrigation being used. Shared the optimal sampling height (10-12 inches) for testing and explained the mandatory summer testing process, which includes selecting 10 leaves per family from the first generation (G1) planted in families. She mentioned that some varieties, like Umatilla and Clearwater Russet, showed slow emergence. Physiological age and immature seed played a role in emergence, and the PVY rate was 0.78% in 2024, with a target of 0.5% for re-certification. PVY increased as the generation number grew, with Norkotah showing particularly high levels in G2 and G3. Testing and roguing strategies were described, as well as the importance of inoculum levels, field placement, and isolation. Several questions were asked regarding the integration of DTT in certification and advice to growers, with an emphasis on staying responsive and maintaining communication with them.

Technical issue with computers

Brooke Babler - Wisconsin Seed Potato Certification Program (9:02-9:25)

Shared that 29 lots were downclassed in 2024, with 16 downclassed to certified and 2 rejected. Rejections higher since 2020, with 6% of lots rejected and 20% downclassed to certified in 2024 due to virus levels. Provided insights into the testing process, including ELISA, visual inspections, and lab testing. Visual and lab testing completed by January 27. The testing also included comparing IC-PCR and ELISA on same tubers following three-week warm period, gassed, and grown out in greenhouse for 119 samples as part of a DTT survey. In 2024, a slight decrease in PVY was observed, although discrepancies in classifications were noted between testing methods. Discussed the efforts to identify PVY strains (O, N:O, NTN, and N-Wi with Chikh-Ali primers) and ongoing work in gel optimization and RNA extraction.

Eric Byre-Minnesota Potato Seed Certification

Shared that Minnesota growers applied to certify 7,061.15 acres for the 2024 crop year, which was a increase from the 6,826.91 entered in 2023. In total 5,253.11 acres were certified-326 withdrawn due to flooding, 8.04 experimental, and 1,474 acres rejected due to severe mosaic and various other issues. Russet Burbank acres were the largest of any variety. Growers saw a delay in planting, then record rainfalls and flooding, and then the growing season turning hot leading to harvest delays. There was 308 samples submitted for the PHT in Hawaii, with 6 grown in the office due to missing the deadline. PHT inspections started Jan 6^th and excellent growing conditions observed in Hawaii this season. Plants expressing visual mosaic symptoms were picked along with negative controls. Latent varieties were screened for PVY. Overall, a increase in PVY this year compared to prior years.

Andrew Houser - Colorado Potato Certification Service (9:49~10:20)

Colorado is currently looking to fill a position in their lab. Provided data on PVY prevalence, noting that 2024 had significantly lower PVY levels compared to recent years, with 1.9% of lots testing positive. Highlighted that extra gassing and variety-specific treatments, like double gassing, can help with dormant varieties (e.g., Waneta and Sangre). Also discussed the Colorado seed law and requirements for plantback testing, as well as the importance of aphid monitoring. He also addressed the use of DTT in testing and survey of growers' confidence in its accuracy and value of earlier results in combination with current growout. A major change for 2025 was also noted, with a requirement for all seed intended for plantback to be tested for PVY.

---30 min Break---

Adam Winchester - North Dakota Seed Potato Certification (10:55-11:15)

Provided an overview of North Dakota’s seed potato regions, with most seed staying within the state. 330 lots were entered and PHT conducted at Pioneer in Waialua, HI. Described field conditions for the 2024 season, noting excellent emergence and vigor despite high virus levels. Latent varieties Silverton, Shepody, Norkotah, and Prospect (new) were noted. Outlined the state’s visual testing and ELISA testing practices, mentioning that 41% of eligible acres had virus levels below 0.5%, but the virus levels in lots were increasing. Discussed state’s work on strain identification and the use of IC-PCR in DTT. Strain concerns include import restrictions and potential NTN impact on processors. Outlined testing of DTT, including timing, composite, and survey studies. Also noted that 2025 would see an expansion of DTT in the certification process.

Jenn Dillinger- Nebraska Potato Certification Association (11:17-11:20)

PHT planted November 20-22, leaf testing conducted December 19-January 18 (late test January 28~). 75 lots were sprout-tested at PCAN. PVY detected in one lot and was rejected.

Damen Kurzer-Michigan Potato Seed Certification Program (11:21-11:44)

Shared that Michigan’s 2023 crop was its largest in state history, but PVY levels were worst since 2010. In 2024, 534 acres certified with 80% chippers, 17% russet, and 3% non-red tablestock varieties. PVY levels were better than 2023. Green peach aphids were noted overwintering in Upper Peninsula in 2024. Mentioned that poor emergence was observed in all PHT lots, with complete failure in 15%. Discussed the use of visual inspections, ELISA, and PCR to test for PVY and emphasized a new policy that lab tests would be required for all new varieties. Also noted that there were differences in PVY strain prevalence, with NTN surpassing N-Wi in 2024. Shared experiences of on-farm coring and strain surveys in identifying virus sources. Additionally, discussed research interests to investigate timing studies, dormancy, and on-farm coring optimization.

Benita Matheson-Washington Potato Seed Certification (11:45-11:57)

Discussed the state of Washington's seed potato certification, with 3,123 acres entered in the program, although the acreage has been decreasing slightly each year. Noted that a change in the BRR isolation zone had been implemented in September 2023, requiring that all lots entering the isolation zone must be tested negative for BRR. During the 2024 season, 35 lots were tested for PVY, all of which came back negative. Also mentioned that one grower was dissatisfied with the PHT and was opting for greenhouse growout. Reported that seed potato isolation district appears to continue to be effective.

12:00 pm ---Break for lunch 45 min---

12:50 pm PVY Research Updates -

Erik Wenninger-Unravelling Relationships Among Aphids, In-season PVY, and PVY Post-harvest-Part 1 (12:50-

Discussed the complex relationship between aphids, PVY, and the factors that influence its transmission. Highlighted that over 65 aphid species are involved in PVY transmission, with the green peach aphid using potato as a reproductive host but non-colonizing aphids are more important for transmission in most areas, including Idaho. Factors contributing to risk of PVY: PVY in seed, timing of aphid flights, PVY in aphid vectors, age-related resistance. Discussed the impact of various insecticides and crop oil treatments on PVY transmission, noting that while oil alone significantly reduced PVY compared to nontreated control, combining oil with insecticides showed a further numerical reduction. Mentioned the challenges in monitoring aphid populations and PVY spread, as aphids often originate from weeds and other crops, making them difficult to track accurately.

Nora Olsen-Unravelling Relationships Among Aphids, In-season PVY, and PVY Post-harvest-Part 2

Presented her research on PVY spread in fields with monitored aphid populations. Observed that PVY increased substantially from July to August, correlating with aphid activity prior to vine kill. Also found spatial differences in PVY levels across seed lots, which indicated that the placement of seed lots within a field may affect PVY incidence. Work involved direct aphid testing using PCR, although this method was abandoned due to the large number of negative results. Findings indicate leaf sampling in August and winter growout were correlated and late-season sampling may provide potentially useful information of PVY levels (more than in June and July).

Alex Karasev-Unravelling Relationships Among Aphids, In-season PVY, and PVY Post-harvest-Part 3 (1:25-1:38)

Continued the discussion on PVY strain identification from the six seed lots described previously using ELISA and RT-PCR tests. Strain O was detected in one plant and determined to be the PVY O5 type, which had not been seen in the U.S. since 2010. Overall, research detected N-Wi, NTN, and PVY O strains. Highlighted that monitoring aphid populations and abundance may correlate with PVY levels in leaf samples at the end of the season, which may help predict PVY incidence in winter growout.

1:30 pm PVY Research Updates-Continued

Jonathan Whitworth-PVY Over Time, Efforts to Research and Educate (1:40-1:57)

Reviewed the changes in PVY strains over the years, noting that the primary strain used to be PVY O, but now N-Wi and NTN are more prevalent. Growers have had formative experiences with PVY O but has been largely displaced. Many latent varieties are known with Russet Burbank and Norkotah noted as particularly susceptible to PVY. Highlighted demo plot efforts from 2016, -18, -22, and -24 and the development of the University of Maine PVY symptom gallery. Also discussed efforts to bring resistance to PVY into new potato varieties, focusing on one to several Ry genes, which provide resistance to multiple strains and isolates (e.g., Payette, Lady Liberty, Mackinaw, Ciklamen). Announcement of PAA July 27-31, 2025 in Madison, WI.

John Onditi-Characterization of the Nature of PVY Resistance in the Potato Variety Bistra (russet variety) (1:59-2:10)

Presented research on the nature of PVY resistance in the russet potato variety Bistra. Identified a quantitative trait locus (QTL) on chromosome 11, which may correspond to the Ryadg gene, known for extreme PVY resistance. However, current markers do not confirm its identity, as noted in Ellison et al. (2024). Grafting inoculation showed Bistra's resistance resembled extreme resistance rather than a strain-specific hypersensitive response. Bistra has Sante in its lineage, a variety with Ryadg and Rysto genes. Mentioned Castle Russet carries Rysto. It was noted that alternative adg markers were previously developed under similar uncertain conditions.

Andrew Houser-The Effect PVY has on Potato Yield & Quality in Colorado (2:10-2:25)

Discussed the impact of PVY on potato yield and quality in Colorado. With the Colorado Seed Law introduced in 2012 and new plantback testing starting in 2024, studies have shown yield losses associated with different PVY strains. Field data from single-plant tests revealed that Reveille, when infected with PVY O, produced significantly fewer and smaller tubers. Norkotah 278 also suffered from reduced yield, larger tuber loss, and increased growth cracking. He emphasized that replanting clean seed is more cost-effective than using infected material, with an estimated loss of 1–3 cwt per 1% PVY infection. Early vine kill was highlighted as a crucial management strategy.

Nina Zidack-PVY-How do We Address Training for Uniform Seed Potato Inspection and Testing in the US? (2:28-2:49)

Focused on strategies to improve uniform training for seed potato inspection and testing across the U.S. Suggested expanding laboratory and inspector training, creating a validation network for ring testing, and possibly developing a fee-based inspector school. Curriculum could include modules on potato certification, varietal ID, disease recognition, virus plots, and sampling strategies. Referenced the 2016 SCRI-supported inspector training and proposed leveraging PAA workshops and Potatoes USA support to establish a 2–3-day training program. Accreditation options and inclusion of agronomists were also discussed.

3:00 pm Tobacco Rattle Virus/Mop-Top/Powdery Scab/Cultivar Development Research Update

Kylie Swisher Grimm-Update on TRV and PMTV Research (3:12-3:36)

Provided updates on TRV and PMTV. Highlighted the complexity of symptom expression due to possible co-infection and vector variability. Despite using two commercial nucleic acid extraction kits, detection of TRV was initially unsuccessful. Castle Russet appeared to lower TRV load, according to greenhouse studies (Quick et al. 2020). In 2023 field trials, Castle Russet showed no symptoms, while Ranger exhibited visible disease. In 2024, differences in TRV load were found in Castle Russet post-season, no differences in pre- and post-season Ranger. Additionally, reported that planting PMTV-infected seed led to detectable virus in daughter tubers, but environmental conditions and clean practices significantly influenced disease development.

Max Feldman-USDA-ARS WA Potato Breeding for Virus Resistance (3:36-3:55)

Shared USDA-ARS breeding updates from the Tri-State program. Team evaluated TRV resistance in advanced lines and found low incidence of corky ringspot (CRS) in germplasm. Payette and Castle Russet emerged as promising cultivars with multiple resistances. Described tools for QTL development and genotyping platforms like the Illumina SolCap array and DArTseq, which is substantially more affordable. SNP markers TRNL and YES3A showed promise, results for TRV20/TRV490 were not clear. PA99N82-4 was noted as potentially TRV-resistant, and both male and female parents were shown to influence tuber size traits.

Sagar Sathuvalli-An Update on Breeding for Resistance to Tuber Necrotic Viruses (3:56-4:12)

Confirmed Castle Russet resistance to CRS and insensitivity to PMTV. Research identified PVY adg resistance derived from Eva, which is also immune to PVY and PVX. QTLs for CRS were mapped to chromosome 9. And resistance to powdery scab was found in POR08BD1-3, Mesa Russet, and Summit Russet, which exhibited root galling resistance linked to two QTLs on chromosome 7. Also reported the discovery of four unique R genes in the Ryadg region, pending further validation.

Noelle Anglin-Expect the Unexpected-PMTV the black swan of viruses (4:14-4:31)

PMTV the “black swan” of potato viruses due to its unpredictable behavior. In a three-year trial, PMTV pressure peaked in 2021 and 2023 but was lower in 2022. In 2021 and 2022, single-plant studies showed that Clearwater and Pomerelle had increased virus levels (lower Ct values) 4-5 months after harvest. Sampling across different tuber parts revealed minimal internal variation before sprouting, with more variability after sprouting but no clear pattern.

4:30 pm Diagnostic Research Updates

Manoj Karkee-AI-enabled Robotic System for Tissue Sampling of Potato Tubers (4:32-5:04)

Presented a robotic AI-enabled system for automated tissue sampling in potato tubers. System integrates machine vision, a manipulator arm, and an end-effector to identify and extract tissue from tubers on a conveyor line. The model, based on YOLO (You Only Look Once), achieved 98.5% tuber detection accuracy and 92.4% for identifying eyes and stolon scars. The robotic system reached about 80% sampling success, with failures largely due to insufficient tissue penetration and deposition.

Heidi Falzon-PVY Antibody Optimized for Immunocapture (5:05-5:13)

Introduced a PVY antibody optimized for immunocapture, enhancing detection through a hybrid serological-molecular approach. Unlike conventional ELISA reagents, Agdia developed monoclonal antibodies from purified PVY N-Wi and NTN strains that provided a 2–3 cycle improvement in detection compared to previous ELISA CAB antibody. The new IC antibody showed greater sensitivity and results comparable to winter growout trials. Agdia is planning direct tuber testing and pricing will be based on test volume.

Mohamad Chikh-Ali-Duplex Immunocapture qRT-PCR for Large-scale Detection of Potato Mop-top Virus in Dormant Potato Tubers (5:14-5:21)

Duplex immunocapture RT-qPCR developed for larger-scale PMTV detection in dormant tubers. As Colorado expands fresh potato exports, especially to Mexico, emphasized the need for reliable diagnostics. Past research had issues with false negatives for PMTV isolates. Study showed improved detection when sampling stem ends and bud cores, however, false negatives were noted to increase toward the rose end. The duplex format offered reliable sensitivity and scalability for certification labs.

5:20 pm Other Business

Election of Secretary (motion to nominate Mohamed Chikh-Ali by Alex Karasev, seconded Nina Zidack)

Impact Statement, publications from 2024 (publications send to Brooke/Chaks/Jaime - will send a reminder email)

Locations for next year’s meeting and date (Austin, Tucson, Miami/Tampa Florida, San Diego or potential dates March 3-4 or 10-11)

Will calculate meals/room fees for in person attendees - invoice together from UW-Madison email

5:30 pm Adjourn (motion to adjourn Nina Zidack, seconded by Alan Westra)

Wednesday March 12, 2025

8:00 am – 5:00 pm SCRI Research Meeting, separate agenda available