SEED POTATO QUALITY IMPROVEMENT.

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1003069
• Project Start Date: Jul 2, 2014
• Project End Date: Feb 3, 2016
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIV OF IDAHO
875 PERIMETER DRIVE
MOSCOW,ID 83844-9803

Performing Department
Plant Soil & Entomological Sci

Non Technical Summary
Some of the most important challenges that face the seed potato industry are the potato viruses such as potato virus Y (PVY) and potato leaf roll virus (PLRV). Another important seed borne disease is bacterial ring rot (BRR). Significant developments have taken place over the last several years in our understanding of the potato virus Y complex (PVY) which is now made up of not only the PVYo (ordinary strain), but also includes the PVYn (tobacco veinal necrosis strain) and the PVYntn (potato tuber necrotic strain) variants. In addition, more and more previously unreported viral strains, probably recombinants, with new and unknown capabilities continue to be discovered within U.S. seedstocks. The impact of PLRV (and the serious "net necrosis" tuber symptom that it causes) was greatly reduced by the advent of systemic insecticides, such as imidacloprid, that effectively control the aphid vectors of the virus. While the amount of PLRV in Idaho seed lots has not rebounded to high levels, there appears to have been a small but steady increase over the last three years. BRR is a disease that follows a cyclic pattern of boom and bust within the seed potato industry. The ebb and flow of this disease is due to a greater emphasis on sanitation during outbreaks followed by a gradual relaxation in sanitation over the next few years following the initial outbreak. Lax sanitation leads to resurgence in the disease and the cycle is repeated. New and far more powerful detection techniques in the form of Real-time PCR have given the industry the ability to detect this disease at levels unheard of just few years ago. The application of these new detection techniques combined with a constant emphasis on sanitation should allow the industry to break these seemingly inevitable cycles and put the disease into remission.

Animal Health Component

100%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
212	1310	1160	100%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
1310 - Potato;

Field Of Science
1160 - Pathology;

Keywords

potato

seed potato

pvy

plrv

virus transmission

brr

sanitation

real time pcr

Goals / Objectives
The overall objective of the proposed research is to bring about an improvement in the health and quality of Idaho seed potatoes. Within this overall objective, this Hatch project will concentrate on management of 1) the potato mosaic virus complex, a disease problem that, with the advent of tuber necrotic strains of virus, has a high potential to cause serious quality losses and 2) The bacterial ring rot disease of potato. The research will concentrate on developing recommendations for managing these two diseases with possible certification recommendations as well as in-season and post-harvest management protocols.

Project Methods
Investigate methods to better identify seed lots with high levels of virus and target them for removal from the seed system. Seed lots intended for recertification will be tested for the mosaic viruses during the winter test grow outs. This information will be shared with the seed producer with the recommendation that seed lots with mosaic virus levels greater than 0.25% not be planted for recertification.Monitor the occurrence of PVYn, PVYntn and possible new strains or recombinants using ELISA and PCR techniques. Potato plants or tubers that test positive for PVYn will be sent to the laboratory in Moscow for further characterization using PCR. This investigation will concentrate on identifying strains of PVYn and ntn as well as new or recombinant strains. Expand the monitoring efforts to include screening for PLRV.Monitor and confirm BRR occurrences within the Idaho industry. Positive finds will be followed up with extension activities to outline the best management practices to eliminate the disease from the affected farming operation and the steps to follow that will prevent future occurrences.

Progress 07/02/14 to 09/30/14

Outputs
Target Audience: Growers, industry representatives, county faculty Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? OUTPUTS: Thirty-five early generation seed lots, planted for recertification in Idaho, from various out of state and in state seed sources were sampled and tested with ELISA to determine actual mosaic virus content. A 400 leaf sample was tested to determine the actual percentage of mosaic that was planted. Fifteen varieties originating from seed sources in ID, MT, ND, NE, and Canada were represented. Only seven seed lots tested positive for PVY. None of the lots tested positive for potato leaf roll virus or for PVA Results from this survey has been presented to the industry in trade journal articles and in oral presentations. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? After the percentages of PVY in Idaho seed potatoes had declined for each of the previous four years, the industry experienced a slight increase last year. However, this slight increase in Idaho seed was only a fraction of the increases suffered throughout the rest of the US. Even with the increase, almost eighty percent of Idaho seed lots were still eligible for recertification.

Publications

• Type: Other Status: Published Year Published: 2014 Citation: Nolte, P. and N. Olsen. Bacterial Ring Rot Update: Latent Testing Information. Potato Grower Magazine. 42(11) November, 2013.
• Type: Other Status: Published Year Published: 2014 Citation: Nolte, P, and A Westra. Aloha! Idaho winter seed test report. Potato Grower Magazine. 42(5):36-37. April, 2014.
• Type: Other Status: Published Year Published: 2014 Citation: Nolte, P. The Job's Not Finished. Potato Grower Magazine. 43(11) November, 2014. Potato Grower Magazine 43(11):62-63.
• Type: Other Status: Published Year Published: 2014 Citation: Nolte, P. Bacterial Ring Rot Update. Proceedings of the 48th Annual Montana Seed Potato Seminar, November 13-14, 2013.
• Type: Other Status: Published Year Published: 2014 Citation: Nolte, P. Seed Piece Decay: Proven Management Practices. Proceedings of the Washington-Oregon Potato Conference. January 26-30, 2014.
• Type: Other Status: Published Year Published: 2014 Citation: Nolte, P. Bacterial Ring Rot: Review of Biology and Management. Proceedings of the Washington-Oregon Potato Conference January 26-30, 2014.