1. Plum Pox Virus Ellis, McKellar, and Hodges. December 2006. NPDN Publication No. 0004

2. Plum Pox Virus Introduction Symptoms Hosts Transmission Detection Control Photo: Biologische Bundesanstalt Archives, Germany http://www.ipmimages.org

3. Introduction Originals observations of the disease were made by plum growers in Bulgaria in the mid 1910s. In Europe the virus is known commonly as “Sharka.” 1999 – PPV detected in Pennsylvania 2000- Ontario, and Nova Scotia 2006 – Confirmed in New York and Michigan Photo: Biologische Bundesanstalt Archives, Germany http://www.ipmimages.org

4. Map provided by EPPO (European and Mediterranean Plant Protection Organization) http://www.eppo.org/QUARANTINE/virus/Plum_pox_virus/PPV000_map.htm

5. Map Source: Canadian Food Inspection Agency http://www.inspection.gc.ca/english/sci/sur v/2003maps/ppvonqz 2003e.shtml Confirmed Locations of PPV in the United States

6. PPV does not kill trees but causes yield losses and reduces the marketability of fruit. In Europe, reported losses of 80-100% in susceptible cultivars PPV belongs to the genus Potyvirus in the family Potyviridae PPV characterized into 4 serological strains (M,D, EA, and C) PPV-D most common strain in Western Europe and is found in US and Canada Introduction Photo: Biologische Bundesanstalt Archives, Germany http://www.ipmimages.org

7. Symptoms PPV symptoms may appear on leaves, fruits, flowers, and seeds. Infections are not transmitted through fruit. Infections without symptoms may occur. May show uneven distribution within the tree Severity of symptoms depends upon: –Plant species –Cultivar –PPV strain –Season –Temperature –Location Varied host susceptibility by PPV strain. Photos: Biologische Bundesanstalt Archives, Germany http://www.ipmimages.org

8. Leaves –Yellowing and browning ring patterns, bands, or blotches Fruit –Yellowing and browning ring patterns, bands, or blotches –Misshapen or deformed Flowers –Streaking on the petals –Pigmented ring patterns Symptoms Photo: Biologische Bundesanstalt Archives, Germany http://www.ipmimages.org

9. Hosts Natural hosts of PPV are restricted to the genus Prunus but has been artificially introduced to others –Peaches –Plum –Apricots –Nectarines –Almonds –Sweet cherry –Tart cherry –Some ornamental and wild native Prunus species Photo: Terry Spivey, USDA Forest Service http://www.ipmimages.org Photo: Peggy Greb, USDA Agricultural Research Service http://www.ipmimages.org

10. Transmission Introduction to new regions through propagative materials and distribution of contaminated materials –Live nursery stock –Grafts –Budwood Photo: Carroll E. Younce, USDA Agricultural Research Service http://www.ipmimages.org

11. Once in a region, spread occurs by aphid transmission Efficiency of transmission determined by: –Virus strain –Host cultivars, –Age of host cultivars –Aphid species –Time of year Transmission Photographer: Whitney Cranshaw, Colorado State University http://www.ipmimages.org Myzus persicae

12. PPV has been transmitted by at least 20 aphid species Most important vectors in Pennsylvania: –Myzus persicae –Aphis spiraecola Transmitted by transient (moving through orchard) and colonizing (staying in the orchard) aphids Transmission Photo: Scott Bauer, USDA Agricultural Research Service http://www.ipmimages.org Myzus persicae

13. Piercing-sucking mouthpart probes vascular tissue of plants while feeding, PPV sticks to the food canal Injected into another plant as aphid feeds PPV can be acquired by probes as brief as 30 seconds PPV transmitted usually within 1 hour Most aphids cannot transmit virus over 120 meters from initial source plant Transmission Photographer: Whitney Cranshaw, Colorado State University http://www.ipmimages.org

14. Detection PPV physical symptoms may not appear for 3 years after initial infection if at all. Serological and molecular tests used to detect virus before symptoms occur – ELISA. Diagnostic hosts, such as Chenopodium foetidum, can be used to detect PPV by mechanical inoculation from suspect hosts Woody indicator plants are also useful for detecting the virus by chip budding to hosts. This method allows for the differentiation of the M and D strains based on symptoms. Photo: Scott Bauer, USDA Agricultural Research Service http://www.ipmimages.org Chenopodium foetidum

15. More sensitive and accurate detection of PPV possible through RT-PCR (reverse transcription polymerase chain reaction) technology Currently, rapid detection of PPV with RT-PCR is achieved with Real-Time PCR PCR can make diagnosis with low concentration of the virus About 5000 times more sensitive than ELISA Detection Real-time PCR utilized for rapid PPV detection. (Photo Dawn Dailey-O’brien, Cornell University) RT-PCR assay. Lane 1 is healthy;Lanes 2-4 are PPV infected. Courtesy L.Levy. Reproduced from L. Levy, V. D. Damsteegt, R. Scorza, and M. Kölber, Plum Pox Potyvirus Disease of Stone Fruits, 2000, APSnet feature, http://www.apsnet.org/onl ine/feature/PlumPox/Top. html

16. No chemical controls available to prevent, eliminate, or cure PPV in the field. If you suspect PPV, http://www.csrees.usda.gov/qlinks/partners/sta te_partners.html –contact your local cooperative extension agent http://www.csrees.usda.gov/qlinks/partners/sta te_partners.html –NPDN lab http://www.npdn.org Control Photo: John Hammond, USDA Agricultural Research Service, http://www.ipmimages.org

17. Control Exclusion and Quarantine – In order to prevent the introduction of the virus into new areas of the US… –All plant material should be carefully regulated and inspected. –All imported host plants should be tested for plant pathogens. –Growers should purchase only certified virus-free planting stock. Exercise extreme caution when purchasing plants! Restrictions protect Growers! The Plant Disease Diagnostic Clinic, Cornell University (2001)

18. Eradication - –Control spread by eliminating infected trees as quickly as possible. –Suspected trees must be sampled multiple times due to the uneven distribution of PPV within a plant. –Infected trees should be bulldozed or cut and sucker shoots eradicated with herbicides. Control The Plant Disease Diagnostic Clinic, Cornell University (2001) Photo: Robert F. Wittwer, Oklahoma State University http://www.ipmimages.org

19. Insect Control - –Insecticides do not effectively control aphid populations. –Only one infected aphid is needed to spread PPV. –Positive trees should be destroyed. –Insecticides may be applied to aphids prior to tree destruction in order to possibly reduce the number of infected areas in geographic area. Control Photographer: Whitney Cranshaw, Colorado State University http://www.ipmimages.org

20. Plant Breeding and Genetic Engineering –Breeding plant resistance from naturally occurring genes in fruit trees. –Genetic engineering may allow scientists to enhance resistance. The Plant Disease Diagnostic Clinic, Cornell University (2001) Control Photo Courtesy R. Scorza. Reproduced from L. Levy, V. D. Damsteegt, R. Scorza, and M. Kölber, Plum Pox Potyvirus Disease of Stone Fruits, 2000, APSnet feature, http://www.apsnet.org/online/feature/PlumPox/Top.html Transgenic C5 Plum resistant to PPV contains the PPV Coat Protein (Photo Scott Bauer, USDA-ARS, http://www.ars.usda.gov/is/graphics/ph otos/sep01/k8891-19.htm)

21. References Levy, L. Damsteegt, V., Scorza, R., and Kolber, M. 2000. Plum pox – potyvirus disease of stone fruits. The American Phytopathological Society. http://www.apsnet.org/online/feature/PlumPox/Top.html http://www.apsnet.org/online/feature/PlumPox/Top.html Levy, L. 2001. ELISA laboratory protocols for the plum pox virus national surveillance program. APHIS-USDA. http://www.aphis.usda.gov/ppq/ep/plumpox/protocols.pdf http://www.aphis.usda.gov/ppq/ep/plumpox/protocols.pdf APHIS-USDA. Emergency and Domestic Programs – Plum Pox. http://www.aphis.usda.gov/ppq/ep/plumpox/background.html http://www.aphis.usda.gov/ppq/ep/plumpox/background.html Plant Disease Diagnostic Clinic. 2001. Plum Pox Virus Factsheet. Cornell University. http://plantclinic.cornell.edu/FactSheets/plumpoxvirus/plumpo x.htm http://plantclinic.cornell.edu/FactSheets/plumpoxvirus/plumpo x.htm

22. Additional Websites: A list of federal, state, university, international, and organization websites about Plum Pox Virus can be found at the USDA, National Agricultural Library, National Invasive Species Information Center http://www.invasivespeciesinfo.gov/mic robes/plumpox.shtml

23. Acknowledgments Editorial Review Dr. Ruth Welliver, Pennsylvania Department of Agriculture Karen Snover-Clift, Cornell University, NEPDN Associate Director Background photo: Carroll E. Younce, USDA Agricultural Research Service http://www.ipmimages.org

24. Authors Amanda M. Ellis, ellisam@ufl.edu,ellisam@ufl.edu University of Florida, SPDN Mary M. McKellar, mem40@cornell.edumem40@cornell.edu Cornell University, NEPDN Training Coordinator Amanda C. Hodges, Ph.D., achodges@ufl.eduachodges@ufl.edu University of Florida, SPDN Assistant Director

25. Publication Details This publication can be used for non-profit, educational use only purposes. Photographers retain copyright to photographs or other images contained in this publication as cited. This material was developed as a topic-based training module for NPDN First Detector Training. Authors and the website should be properly cited. Images or photographs should also be properly cited and credited to the original source. Publication Number: 0004 Publication Date: December 2006