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

Plum Pox Virus

Ellis, McKellar, and Hodges. December 2006.NPDN Publication No. 0004

Plum Pox Virus• Introduction

• Symptoms

• Hosts

• Transmission

• Detection

• Control

Photo: Biologische Bundesanstalt Archives, Germany http://www.ipmimages.org

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


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

Map Source: Canadian Food Inspection Agency http://www.inspection.gc.ca/english/sci/surv/2003maps/ppvonqz2003e.shtml

Confirmed Locations of PPV in the United States

• 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


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

• 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


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

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 Servicehttp://www.ipmimages.org

• 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

• 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

• 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


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

• 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/online/feature/PlumPox/Top.html

• No chemical controls available to prevent, eliminate, or cure PPV in the field.

• If you suspect PPV, – contact your local cooperative extension agent

http://www.csrees.usda.gov/qlinks/partners/stahttp://www.csrees.usda.gov/qlinks/partners/state_partners.htmlte_partners.html

– NPDN lab

http://www.npdn.org

Control

Photo: John Hammond, USDA Agricultural Research Service, http://www.ipmimages.org

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)

• 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


Photo: Robert F. Wittwer, Oklahoma State University http://www.ipmimages.org

• 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


• Plant Breeding and Genetic Engineering – Breeding plant resistance

from naturally occurring genes in fruit trees.

– Genetic engineering may allow scientists to enhance resistance.


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/photos/sep01/k8891-19.htm)

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

• 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

• APHIS-USDA. Emergency and Domestic Programs – Plum Pox. 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/plumpox.htm

http://www.apsnet.org/online/feature/PlumPox/Top.html

http://www.apsnet.org/online/feature/PlumPox/Top.html

http://www.aphis.usda.gov/ppq/ep/plumpox/protocols.pdf

http://www.aphis.usda.gov/ppq/ep/plumpox/protocols.pdf

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/microbes/plumpox.shtml

AcknowledgmentsEditorial Review

• Dr. Ruth Welliver, Pennsylvania Department of Agriculture

• Karen Snover-Clift, Cornell University, NEPDN Associate Director

Background photo: Carroll E. Younce, USDA Agricultural Research Servicehttp://www.ipmimages.org

Authors• Amanda M. Ellis, [email protected],

University of Florida, SPDN

• Mary M. McKellar, [email protected]

Cornell University, NEPDN Training Coordinator

• Amanda C. Hodges, Ph.D., [email protected]

University of Florida, SPDN Assistant Director

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

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

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