Source: UNIV OF IDAHO submitted to NRP
A MULTIDIMENSIONAL APPROACH FOR THE MANAGEMENT OF THE POTATO VIRUS Y (PVY) POTYVIRIDAE: POTYVIRUS) COMPLEX IN IDAHO
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
0210692
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jul 1, 2007
Project End Date
Jun 30, 2012
Grant Year
(N/A)
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
The potato industry in Idaho and the US is currently being affected by aphid-transmitted viruses such as Potato virus Y (PVY) (Potyviridae: Potyvirus). PVY reduces yields and is jeopardizing the seed production industry. Potato colonizing aphids are the most efficient vectors of PVY. However, aphids that do not colonize potatoes may play an important role in the epidemiology of PVY in Idaho because of their high densities during the summer. Hairy nightshade, an abundantly occurring weed in the PNW, may play an important role in the epidemiology of PVY. Current vector and disease management practices in potato do not incorporate multidiscipline strategies and have proven largely ineffective. This project will determine the importance of hairy nightshade in the PVY epidemiology, test percentage transmission of PVY by three aphid vectors using hairy nightshade and potato as inoculum sources in field experiments, develop management strategies for non-colonizing aphids through adoption of a "Good neighbor strategy" (controlling non-colonizing aphids arising from cereal crops adjacent to potato fields to reduce PVY infection), and incorporate information generated into an overall, effective, multidimensional management plan for vector, disease, and weed control in the PNW. The overall goal of this project will be the development of an improved IPM program for PVY, nightshade, and aphids in potato systems.
Animal Health Component
85%
Research Effort Categories
Basic
15%
Applied
85%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2111310113035%
2121310110125%
2131310113020%
2162410113020%
Goals / Objectives
1. Determine hairy nightshade susceptibility to infection by PVY-strain variants and characterize the respective symptoms in the laboratory/greenhouse and field. 2. Determine the preference of a non-colonizing aphid vector (BCOA) for hairy nightshade compared to potato under laboratory and field conditions. 3. Test the aphid vector efficiency of PVY transmission from hairy nightshade and potato through transmission experiments and RT-PCR (see methodology). 4. Determine percentage transmission of PVYo by three aphid vectors using hairy nightshade and potato as inoculum sources in field experiments 5. Develop management strategies for non-colonizing aphids through adoption of a Good neighbor strategy [explained below in the methods]. 6. Incorporate information generated in the preceding five objectives into an overall, effective, multidimensional management plan for vector, disease, and weed control in the PNW. 7. Disseminate research results to potato growers in the PNW.
Project Methods
This research employs a combination of both laboratory and field experiments that included a wide array of chemical, ecological, serological and molecular tools. All laboratory (insect colonies, virus inoculations and serological and molecular testing) and greenhouse (plant production and maintenance) experiments will be conducted at the University of Idaho Aberdeen R&E Center. Field experiments will be conducted at the University of Idaho Kimberly R & E Center in south-central Idaho and Rexburg in Northeastern Idaho. A detailed description of the procedures for each objective is included in the full proposal.

Progress 07/01/07 to 06/30/12

Outputs
OUTPUTS: The last submitted progress report will serve as the final report. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The last submitted progress report will serve as the final report.

Publications

  • No publications reported this period


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: OBJECTIVES: 1. Study the biological and epidemiological basis for the increased incidence of necrotic strains in the PNW potato cropping systems. 2. Determine the effect of PVY necrotic strains in recently released or soon to be released potato cultivars, including recording foliar and tuber symptoms. To determine the reaction of advanced breeding lines and newly released cultivars to PVY, testing in the greenhouse was done by challenging the plants with three different Potato Virus Y (PVY) strains. The lines/cultivars tested in 2009 include A99326-1PY (Huckleberry Gold), A97066-42LB, A0008-1TE (Teton Russet), A00286-3Y, A00293-2Y. The following lines/cultivars have been collected for testing in February-April, 2011; A97066-42LB, A0008-1TE (Teton Russet), A99326-1PY (Huckleberry Gold), and A98345-1. Yukon Gold is used as a standard susceptible cultivar in each of the trial years. Virus isolates used for 2009 are AL1 (N:O), N4 (NTN), Oz (O). In order to determine the impact of temperature on tuber necrosis caused by PVY strains, a growth chamber experiment was set up in 2010 and is currently in progress. This experiment has three PVYO isolates and one PVYNTN isolate. The growth chamber is set at 27C for 16 hrs light and 20C for 8 hrs dark. The three PVYO isolates have been shown to cause tuber necrotic symptoms which is a reaction not previously reported in the literature. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Dr. Alvarez resigned from the University of Idaho effective Oct. 2010. Dr. Pamela J.S. Hutchinson, University of Idaho Potato Cropping Systems Weed Scientist will be supervising graduate students involved in this project.

Impacts
Results from the 2009 testing showed that Yukon Gold produced necrotic tuber symptoms when infected with the NTN and N:O strains, but not the healthy or O treatments. The only other clone/virus isolate combination that produced symptoms was with NTN and A00293-2Y. At this point results from the effect of temperature experiments have not been collected. Plants that were inoculated with the different virus isolates have been ELISA tested and are all confirmed positive for PVY. A preliminary run of this experiment showed that the experimental parameters were conducive for producing necrotic tuber symptoms.

Publications

  • No publications reported this period


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: After conducting and analyzing several experiments, it was confirmed that aphids efficiently transmitted the necrotic strains to potato and the transmission rates were higher than those with the common PVYO strain. Awareness of aphid-virus-plant interactions in the epidemiology of PVY has been created. The information generated by this project has been delivered to scientific community with 3 professional international papers and 5 national professional papers presented. Information has also been delivered to growers (467) and industry groups through 6 extension talks and workshops. One extension presentation was in Spanish as part of the UI Cooperative Extension System Spanish IPM Training Clinics. I also responded to 79 phone calls, 103 e-mails and more than 10 visits to my office from growers, University of Idaho colleagues, county faculty, industry personnel and homeowners requesting information on hairy nightshades-virus-vector interactions. Indirect outputs include three articles and interviews on PVY-hairy nighshade-vectors published on trade journals. Two symposia were organized on the subject of vector-virus interactions: Insect Vector-pathogen interactions: from the molecule to the field and beyond. 8 talks. Annual PB-ESA Meeting. San Diego, CA, March 29- April 1, 2009. 2) Vector‐Virus Interactions in Agro Ecosystems: Approaches, Advancements, and Limitations. 9 talks, Annual ESA Meeting. Indianapolis, IN, December 13-16, 2009. The workshop "Nightshade & Aphid Management to Control Potato Virus", was presented again at the 2009 Idaho Potato Conference and was very well attended (109 growers, consultants, industry representatives, university researchers, and extension specialists and county educators). Various hairy nightshade and aphid control strategies also were discussed. Letters from PSES Department Head, Dr. Johnson, indicated that the evaluations he received from the extension talks showed "extremely strong clientele satisfaction". PARTICIPANTS: Felix A. Cervantes was a Ph.D. student in my laboratory. He graduated in December 2008 and worked as a Postdoctoral Researcher in my lab from Jan to July 2009. Collaboration has been established with Dr. Jonathan Whitworth, Plant Pathologist with the USDA-ARS Aberdeen. TARGET AUDIENCES: Scientific community working on potato viruses and their insect vectors. Also, Idaho and Pacific Northwest potato growers are my target audience and will eventually benefit from this research as described in the impact section. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This research demonstrated that aphids efficiently transmitted the necrotic strains to potato and the transmission rates were higher than those with the common PVYO strain. Titer of the necrotic strains was higher in aphid-inoculated plants than in mechanically inoculated plants. A trend of higher titer accumulation of these necrotic strains when compared to the one for PVYO was also observed. This research will allow a more complete understanding of the interaction between viruses, and vectors, and aid in development of much needed and improved virus management plan. Impact 1: Once a list of cultivars that are more susceptible to infection is developed, growers will be able to determine what cultivars to plant. Impact 2: New information regarding the efficiency of vectors transmitting the new virus necrotic strains could help predicting the possibility of spread of these strains within crops into other regions. Indicators and evaluation methods: A growing national and international interest in aphid vector-virus interactions research related to PVY management in potatoes is reflected by the invitation from the National Potato Council to present a talk on this subject at the National Potato Expo in San Antonio last January, which is the largest conference for the potato industry in North America. It is the conference that covers the hottest issues facing the potato industry. I was also invited by Idaho Crop Improvement to present a talk on plant-aphid-virus interactions at the Annual Idaho Seed Potato Grower's Seminar in Pocatello last January. An international invited talk was also presented at the 8th International Symposium of Aphids in Italy. Surveys conducted during my extension talks indicated that potato growers were not aware of tritrophic interactions (vectors, viruses and plant hosts) before the workshops. Growers are currently more informed on the importance of additional inoculum sources for viral diseases in the field. Potato growers indicated that they are extremely concerned about managing potato viruses, especially the newly arrived PVY necrotic strains. They have started controlling inoculum sources and scouting them for vector presence.They also implemented more judicial insecticide programs. 68% of the growers present at the talks responded correctly to the questions at the end of these extension talks. This demonstrates the knowledge increase on the pest interactions. Growers responded to surveys indicated they would implement better controls of aphid vectors and plant hosts. Recommendations regarding virus management also were implemented by growers (scouting for aphids, scouting not only the crop but also neighboring cereal crops, reducing hairy nightshade populations, etc.).

Publications

  • Pantoja, A., Hagerty, A.M., Emmert, S.Y., Kuhl, J.C., Pike, K., Alvarez, J.M., and Jensen, A. 2010. Aphids (Homoptera: Aphididae) associated with rhubarb in the Matanuska Valley, Alaska: Species composition, seasonal abundance, and potential virus vectors. J. Entomol. Soc. British Columbia. In press.
  • Alvarez, J.M., Srinivasan, R., and Cervantes, F. 2009. Potato viral infections affect the biology and behaviour of aphid vectors. Redia. 92: 169-170.
  • Nolte, P., Alvarez, J.M., and Whitworth, J. 2009. Potato virus Y management for the seed potato producer. Current Information Series, University of Idaho. CIS 1165. Freely available at: http://info.ag.uidaho.edu/pdf/CIS/CIS1165.pdf
  • Hirnyck, R., Downey-Blecker, L., Jones, W. and Alvarez, J.M. 2009. Field Manual for Potato Pests in English and Spanish. University of Idaho PNW Bulletin 856. (103 pages).
  • Alvarez, J.M., and Cervantes, F. 2009. Potato Virus Y distribution in hairy nightshade and potato upon aphid inoculation. 93rd Annual Meeting of the Potato Association of America. Book of Abstracts: 29.
  • Alvarez, J.M., Srinivasan, R., and Cervantes, F. 2009. The need for a multidimensional potato virus management plan in the Pacific Northwest. 6th International Integrated Pest Management Symposium. Book of Abstracts: 95.
  • Cervantes, F.A., and Alvarez, J.M. 2008. Role of hairy nightshade Solanum sarrachoides (Sendtner) in the transmission of Potato virus Y (PVY) strains by aphids and study of different PVY strains reaction on Solanum tuberosum (L.). Phytopatology 98:S190.


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Awareness of weed importance in the epidemiology of potato viruses has been created. The information generated by this project has been delivered to scientific community with 3 professional international papers and 7 national professional papers presented. Information has also been delivered to growers and industry groups (542 people) through extension talks and two workshops. One extension presentation was in Spanish as part of the UI Cooperative Extension System Spanish IPM Training Clinics. I also responded to 46 phone calls, 48 e-mails and more than 10 visits to my office from growers, University of Idaho colleagues, county faculty, industry personnel and homeowners requesting information on hairy nightshades-virus-vector interactions. Indirect outputs include two articles and two interviews on PVY-hairy nighshade-vectors published on trade journals. A workshop was presented at the 2008 Idaho Potato Conference. The title of this workshop was "Nightshade & Aphid Management to Control Potato Virus". Even though the workshop was the final one on the last conference day, it was very well attended (more than 250 growers, consultants, industry representatives, university researchers, and extension specialists and county educators). Various hairy nightshade and aphid control strategies also were discussed. PARTICIPANTS: Dr. Srinivasan was a support scientist in my laboratory until December 2008 and Felix A. Cervantes was a Ph.D. student in my laboratory. He graduated in December 2008. They both conducted research on several aspects of this project. TARGET AUDIENCES: Scientific community working on potato viruses and their insect vectors. Also, Idaho and Pacific Northwest potato growers are my target audience and will eventually benefit from this research as described in the impact section. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This research has demonstrated that hairy nightshade, a prevalent weed in the same family as potato, is an important host for PVY and its insect vectors. Results from this research suggest that the basis of any virus reduction program in Idaho and the PNW should be reevaluated to place more emphasis on hairy nightshade control. Impact 1. The symptoms produced in hairy nightshade upon infection with necrotic and non-necrotic PVY strains were determined and the percentage of infection and titer accumulation of these strains were studied. Description of these symptoms might facilitate the early detection of the virus in potato fields. Hairy nightshade was similarly infected compared to potato plants (cv. Russet Burbank) using the PVYO and PVYN:O strains. Percentage infection by PVYNTN was higher in hairy nightshade plants than in potato plants. The necrotic strain PVYNTN reached higher titer in hairy nightshade than in potato plants when compared to PVYO and PVYN:O. Impact 2. The influence of hairy nightshade as a virus inoculum source in the epidemiology of PVY in Idaho potato fields was determined. In the three years of this research, transmission of PVY by the three aphid vectors was higher in plots that had a PVY-infected hairy nightshade plant as source of virus inoculum than in plots that had a PVY-infected potato plant. Thus, hairy nightshade is an important component in the potato pathosystem affecting the epidemiology of PVY in Idaho and should be considered in PVY management plans. Indicators and evaluation methods: A growing national and international interest in weed research related to virus management in potatoes was observed. Invited talks and seminar on this subject included: talk at the Annual Oregon Potato Conference in January. Talk at the Syngenta National Meeting. Talk at the National Potato Expo in San Antonio, Texas. International invitations included two talks on the same topic in France: at the first International PVY Wide in Paris, and at the French National Research Institute in Rennes. One talk at the XXIII Latin American Potato Association Congress in Mar del Plata, Argentina. I have been able to increase the working knowledge of farm workers on virus-vector-weed management through my presentations. The 250 growers, consultants, industry representatives, university researchers, and extension specialists and county educators attending the workshop "Nightshade & Aphid Management to Control Potato Virus" were surveyed afterwards for their interest in and perceived usefulness of the information presented. Of those surveyed, 100% found the workshop useful and said they definitely would use the information presented. Of the growers surveyed, 100% said that they would change their practices based on that information. 60% commented that the workshop was the best that they had attended and getting the nightshade, aphid, and virus information all together made them realize how important an IPM approach is for managing this major problem in potatoes. This demonstrates that our agricultural audience in Idaho is now aware of the problems with hairy nightshade as virus and aphid reservoir.

Publications

  • Srinivasan, R. and Alvarez, J.M. 2008. Hairy nightshade as a potential Potato leafroll virus (Luteoviridae: Polerovirus) inoculum source in Pacific Northwest potato ecosystems. Phytopathology. 98:985-991.
  • Srinivasan, R., Alvarez, J.M., Bosque-Perez, N., Eigenbrode, S. and Novy, R. 2008. Effect of an alternate weed host, hairy nightshade, Solanum sarrachoides (Sendtner), on the biology of the two most important Potato leafroll virus (Luteoviridae: Polerovirus) vectors, Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) (Aphididae: Homoptera). Environmental Entomology. 37:592-600.


Progress 08/01/07 to 12/31/07

Outputs
OUTPUTS: The role of hairy nightshade in the epidemiology of PVY was determined during the first field experiment. The ability of hairy nightshade to act as a reservoir of aphids and PVY was demonstrated. The first year experiment also determined the dynamics of the virus-vector-crop-weed pathosystem. Awareness of weed importance in the epidemiology of potato viruses has been created. The information generated by this project has been delivered to scientific community with 3 professional international papers and 4 national professional papers presented. Information has also been delivered to growers through 3 workshops. PARTICIPANTS: Dr. Srinivasan is a support scientist in my laboratory and Felix A. Cervantes is a Ph.D. student in my laboratory. They are both conducting research on several aspects of this project. TARGET AUDIENCES: Scientific community working on potato viruses and their insect vectors. Also, Idaho potato growers are my target audience and will eventually benefit from this research as described in the impact section.

Impacts
Potato virus Y strain reactions on hairy nightshade were characterized. Development of symptoms for PVYO and PVYNTN infected hairy nightshade plants were recorded and compared. The effect of hairy nightshade as virus inoculum host in the transmission of PVYO and PVYNTN by three aphid vectors was also determined. Rates of infection by green peach aphid, potato aphid and bird cherry oat aphid were recorded and compared by inoculum source and also by PVY strain. Before this research, little was known about the involvement of weeds in aphid vector attraction and performance, and PVY epidemiology. The field experiment demonstrated that hairy nightshade is a better inoculum source than potato and increased rates of PVY transmission especially by potato colonizing aphids. Potato aphid seems to be a better PVY vector than green peach aphid and bird cherry oat aphid probably because of its higher mobility. Strains such as PVYO that were dominant are being overtaken by relatively new strains such as PVYN:O and PVYNTN. This new strains are becoming prevalent possibly due to the fact that they accumulate at higher titers in moderately resistant cultivars when compared to PVYO and do not express clear symptoms of infection. Transmission experiments by three aphid vectors demonstrated these facts. This research will allow a more complete understanding of the interaction between viruses, and vectors, and aid in development of much needed and improved virus management plan. These results suggest that the basis of any virus reduction program in Idaho and the PNW should be reevaluated to place more emphasis on hairy nightshade control. Recommendation for nightshade control have been developed and published. Growers in Idaho are now aware of the problems with hairy nightshade as virus and aphid reservoir (75% (56 of 75) responded that they are controlling the weed in a more judicious way in the last two years). Growers also have a more complete understanding of the interaction between the weeds, virus, and vectors (62% (46 of 74) responded that they know that if they have hairy nightshade in the field they will have more aphids and consequently more virus in the crop). Spanish speaking field workers are more knowledgeable about recognizing aphid vectors and virus infections (97% (29 of 30) responded correctly to questions regarding identification of aphid vectors and virus infected plant photos). Growers are finding the information on hairy nightshade (as virus and aphid reservoir) useful (100% (59 of 59) responded that they found the information presented at the annual Potato School useful). There was also an observed international recognition of the Aberdeen entomology program on management of potato viruses and vectors (Alvarez was invited to present Keynote Talk at the 10th International Plant Virus Epidemiology (IPVE) symposium in India.

Publications

  • Srinivasan, R. and Alvarez, J.M. 2007. Effect of mixed-viral infections (Potato virus Y-Potato leafroll virus) on the biology and preference of vectors, Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) (Homoptera: Aphididae). Journal of Economic Entomology. 100:646-655. Available at: http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/002204 93/v100n3s2.pdf
  • Hamm, Boydston, P.R., Hoy, C.W., Hutchinson, P., Stevenson, W., Alvarez, J.M., Alyokhin, A., Boiteau, G., Dively, G., Gudmenstad, N. and Kirk, W. 2007. Managing pesticide resistance. In Potato Health Management D.A. Johnson ed. The American Phytopathological Society, St. Paul, MN. pp. 123-131.
  • Hoy, C.W., Boiteau, G., Alyokhin, A., Dively, G. and Alvarez, J.M. 2007. Managing insect and mite pests. In Potato Health Management D.A. Johnson ed. The American Phytopathological Society, St. Paul, MN. pp. 133-147.