Transcript Slide 1

Ralstonia solanacearum
Race 3 biovar 2
Background photo: USDA APHIS PPQ Archives
http://www.ipmimages.org
Ralstonia solanacearum
Race 3 biovar 2
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Introduction
Hosts
Symptoms
Transmission
Detection
Control
Photo Jean L. Williams-Woodward, University of Georgia,
www.forestryimages.org
Introduction
• Ralstonia solanacearum Race 3 biovar 2 is a
bacterium that causes the following
diseases:
– Southern Wilt of Geranium
– Brown Rot and Bacterial Wilt of Potato
– Bacterial Wilt of Tomato and Other
Solanaceous Crops
• This pathogen is designated as a member of
the Agricultural Bioterrorism Select Agent
List.
Other Ralstonia solanacearum
Races and Biovars
Race
Host Range
Geographic
Distribution
Biovar
1
Wide
Asia, Australia,
Americas
3,4
1
2
Banana
Other Musa
spp.
Caribbean,Brazil
Philippines
1
3
Potato, some
other
Solanaceae,
Geranium;
Worldwide except
US and Canada
2
4
Ginger
Asia
3,4
5
Mulberry
China
5
(Daughtrey, 2003 Reprinted, with slight modification, from Denny and Hayward, 2001)
Global Distribution
• World wide losses from
bacterial wilt on potato
crops are more than $950
million per year (Allen 2003).
• Outbreaks of R.
solanacearum Race 3 biovar
2 have occurred throughout
Europe in recent years.
• These outbreaks are thought
to be the result of imports of
infected plant material from
locations where the disease
is already established (Janse
1996).
Photo H.D. Thurston, Cornell University, http://www.tropagfieldtrip.cornell.edu/docthurston/Thumbs%20%20Brown%20Rot/Brown%20Rot.html
History in United States
2005 - 2006
Testing but no positives - Yet
Detection on cuttings from
Guatemala, no additional sites
found
2003
Detection on cuttings from Kenya,
127 greenhouses in 27 states
2002
No Reported Cases
2001
No Reported Cases
2000
Introduction of Rs R3b2 on
geranium cuttings
1999
Introduction of Rs R3b2 on
geranium cuttings
Photo Peggy Greb, USDA-ARS
(Year)
Race 3 commonly found
throughout the world except for
United States and Canada
Hosts
• Hosts of Ralstonia
solanacearum
Race 3 biovar 2
include several
solanaceous
plants:
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Photo H.D. Thurston, Cornell University, http://www.tropagfieldtrip.cornell.edu/docthurston/Thumbs%20%20Brown%20Rot/Brown%20Rot.html
Potato
Tomato
Eggplant
woody nightshade
• Geranium
(Pelargonium
spp.) can also
serve as a host.
Symptoms on Geraniums
• Yellowing, wilting
and browning of
lower leaves
• Vascular
discoloration and
necrosis of the stem
• Brown discoloration
of the roots
Photos Margery Daughtrey, Cornell University, www.pdis.org
Signs on Geraniums
• Bacterial Ooze
• Bacterial streaming:
cut stem or petiole
placed in water
should display
cloud generated
from bacterial
streaming out of
plant tissue
Bacterial ooze
Photo Margery Daughtrey, Cornell University, www.pdis.org
Bacterial
Streaming
Photo David B. Langston, University of Georgia, www.forestryimages.org
Signs and Symptoms on
Potato Plants
Foliage
• Stunting
• Yellowing
• Wilting, initially limited
to top of plant
Stem
• Vascular discoloration
• Collapse in young
plants
• Bacterial ooze
• Bacterial streaming
Photos H. David Thurston, Cornell University,
http://www.tropagfieldtrip.cornell.edu/docthurston/Thumbs%20%20Brown%20Rot/Brown%20Rot.html
Signs and Symptoms
on Potato Tubers
•Discoloration of the
vascular ring
•Bacterial ooze,
which in later
stages may
emerge from eye Bacterial Ooze
and heel
Photo Plant Protection
Service Archives,
Netherlands,
www.forestryimages.org
Photo Central Science Laboratory, Harpenden Archives, British
Crown, United Kingdom, www.forestryimages.org
Signs and Symptoms
on Tomatoes
Images are of
Ralstonia
solanacearum Race
1 not Race 3.
Symptoms of Race
3 biovar 2 on
tomato can be
similar.
• Wilting
• Vascular
discoloration
• Bacterial ooze
Photos Clemson
University - USDA
Cooperative Extension
Slide Series,
www.forestryimages.org
Vascular
Vascular
Discoloration
Discoloration
Transmission
• Contaminated soil,
irrigation water,
surface water,
equipment and
personnel
• Pathogen may enter
plants via wounds
from handling or
nematode feeding
Photo Anson Eaglin, USDA-APHIS , www.forestryimages.org
Transmission
Infected plant material
– In geraniums: spread
through the use of
infected cuttings
– In potatoes: spread
through infected
potato seed stock
Photo by Peggy Greb, USDA-ARS,
http://www.ars.usda.gov/is/graphics/photo
s/jan03/k10149-1.htm
Detection and Diagnosis
The diagnosis to Race and biovar
can be difficult often requiring
several diagnostic tests to make a
final diagnosis.
Culture of R. solanacearum on
TZC semi-selective medium
• Isolation on Semi-Selective
Medium
– Use of medium selective
for R. solanacearum not
to Race or biovar
• ELISA
– Only specific for
Ralstonia solanacearum
not Race and biovar
– Used for initial screening
of large quantities of
materials
Photo Tom Creswell, NCSU , www.forestryimages.org
Detection and Diagnosis
• Testing to Determine
Race and Biovar
– Carbon Utilization
Testing (used to
differentiate biovar)
– Real Time PCR (used
to differentiate Race)
Real-time PCR used for
determination of race of R.
solanacearum. (Photo Dawn DaileyO’brien, Cornell University)
Control: Potato
• No chemical control
available
• Removal of weed hosts
such as woody
nightshade which is
thought to act as a
reservoir for inoculum
• Altering soil pH over
the course of the
growing season
• Screening tubers for
disease before planting
in the field
• Rotation with nonsusceptible crops
Woody nightshade can serve as a host
for R. solanacearum Race 3 Biovar 2 and
a source of inoculum for potato crops
Photo Joel Floyd, USDA APHIS PPQ,
www.forestryimages.org
Control: Tomato
• Plant derived chemical:
Thymol has been used
as a pre-plant soil
fumigant with some
success (Momol 2006).
• Plant breeding efforts
have resulted in some
tomato breeds with high
resistance but also
some undesirable traits
like small fruit (Momol
2006).
Photo Keith Weller, USDA-ARS,
http://www.ars.usda.gov/is/graphics/photos/dec99/k735
3-7.htm
Control: Geranium
• No chemical control
available
• Control relies on
eradication of infected
plants and proper
sanitation practices
– Limit greenhouse access and
practice good sanitation
techniques
– Water monitoring for presence
of pathogen
– Clean irrigation system on a
regular basis
– Culture index plant material 1-3
years to ensure it is disease
free
– Practice weed control programs
within and around greenhouses
Photo © Br. Alfred Brousseau, Saint Mary's College,
http://calphotos.berkeley.edu/
USDA-APHIS-PPQ Pest Data Sheet
Ralstonia solanacearum Race 3 Biovar 2
Lemay et al. 2003
References
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Allen, C. 2003. Bacterial Wilt Disease & Ralstonia solanacearum. Talk from 2003 Ralstonia Solanacearum race 3 biovar 2
Outbreak in Geraniums: A Program Review meeting held June 17 and 18, 2003 in Riverdale, MD.
Daughtrey, M. 2003. New and Re-emerging Diseases in 2003. Department of Plant Pathology, Cornell University, Long
Island Horticultural Research & Extension Center.
Denny, T. P. and Hayward, A.C. 2001. Ralstonia, pages 151-174 in: Schaad, N. W. et al. Laboratory guide for the
identification of plant pathogenic bacteria, 3rd ed. APS Press, St. Paul, 373 pp.
Elphinstone, J. and Harris, R. 2002. Monitoring and control of the potato brown rot bacterium in irrigation water. British
Potato Council report 190. http://www.potato.org.uk/upload/pdf/researchReports/report190.pdf. Accessed 2004 January 8.
Elphinstone, J. January 2004. Personal communication. EC project number: SMT project CT97-2179.
Harris, D. C. 1972. Intra-specific variation in Pseudomonas solanacearum. Pages 289-292 in: Proc. Int. Conf. Plant Pathog.
Bact., 3rd.
Janse, J. 1996. Potato Brown rot in western Europe – history, present occurrence and some remarks on possible origin,
epidemiology and control strategies. Bulletin OEPP/EPPO 26: 679-695.
Kim, S. H., Olson, R. N. and Schaad, N. 2002. Ralstonia solanacearum Biovar 2, Race 3 in geraniums imported from
Guatemala to Pennsylvania in 1999. Plant Disease 92:S42.
Kim, S. H., T. N. Olson, N. W. Schaad, and G. W. Moorman. 2003. Ralstonia solanacearum Race 3, Biovar 2, the Causal
Agent of Brown Rot of Potato, Identified in Geraniums in Pennsylvania, Delaware, and Connecticut. Plant Disease Page
87:4.
Lemay, A., Redlin, S., Fowler, G., Dirani, M. 2003, February 12. Pest Data Sheet Ralstonia solanacearum race 3 biovar 2.
USDA/APHIS/PPQ Center for Plant Health Science and Technology Plant Epidemiology and Risk Analysis Laboratory
Raleigh, NC.
Momol, T. 2006, October 12. Recovery Plan for Ralstonia solanacearum Race 3 biovar 2, Causing Brown Rot of Potato,
Bacterial Wilt of Tomato and Southern Wilt of Geranium. National Plant Disease Recovery System.
http://www.ars.usda.gov/SP2UserFiles/Place/00000000/opmp/Rs3-2RecoveryPlan-v-Oct112006.pdf. Accessed 2006 October
17.
O’Hern, C. 2004 January 5. Detection of Ralstonia solanacearum race 3 biovar 2 in New York Greenhouse (document by
Richard Dunkle) [Distribution list]. Accessed 2004 January 5. USDA-ARS Plant Health Division. 2002. Potato Brown Rot
(RALSTONIA SOLANACEARUM) Report on monitoring and eradication in England 2002. Defra, Plant Health Division.
http://www.defra.gov.uk/planth/phnews/monrad02.pdf. Accessed 2004 January 8.
Williamson, L., Nakoho, K., Hudelson, B. and Allen, C. 2002. Ralstonia solanacearum race 3, biovar 2 strains isolated from
geranium are pathogenic on potato. Plant Dis. 86:987-991
Additional Websites
• A list of federal, state, university,
international, and organization
websites about Ralstonia
solanacearum Race 3 biovar 2 can be
found at the USDA, National
Agricultural Library, National Invasive
Species Information Center
http://www.invasivespeciesinfo.gov/micr
obes/bacterialwilt.shtml
Acknowledgements
Editorial Review
• Margery Daughtrey, Cornell University
Long Island Horticulture and Extension
Center
• Dr. Tim Momol, University of Florida,
North Florida Research and Education
Center
Authors
• Mary M. McKellar, [email protected]
Cornell University, NEPDN Training
Coordinator
• Karen Snover-Clift, [email protected]
Cornell University, NEPDN Associate
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: 020
• Publication Date: April 19, 2007