Post on 24-Jun-2015
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International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Fen Beed, Ranajit Bandyopadhyay, Leena Tripathi, Jaindra Tripathi,
Komi Fiaboe, DJ Kim, Lava Kumar, Hein Bouwmeester, Muris Korkaric,
Valentine Nakato, Idd Rathamani, Piet van Asten, Maina Mwangi,
Steffen Abele, Jim Lorenzen
BANANA XANTHOMONAS WILT
RESEARCH AT IITA
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
• Diagnostics
• Disease surveillance
• Epidemiology
• Disease management
• Host plant resistance
Key activities
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Field Diagnostics
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Increase awareness
• To farmers?
What do I do?
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Increase awareness to farmers of disease symptoms
and methods of control
runyankole
luganda
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Mobile plant clinics
• direct help to growers
• surveillance of common and emerging diseases
• gathers demand for control technologies
• determines impact of control technologies
Field
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Mobile plant clinics
Monitoring of common and emerging diseases and efficacy of control methods
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Disease surveillance: IITA / NARO / Grameen
• Pilot disease surveillance study using SMS phone technology and community knowledge workers for BXW and BBTD
• Provide 2 way communication between science (diagnosis and control) and practice (grower’s observations and needs)
• Collate survey data (incidence and surveillance) for use by government for contingency planning to control diseases and safeguard trade
• To be out-scaled to increased number of districts and to cover all banana diseases (and hopefully for other crops towards providing a bidirectional extension service operated by e.g. NAADS)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Selective CCA Non-selective YPGA
Semi-selective media
Diagnostics: Semi-selective media
Selective YTS-CC
Mwangi et al. 2007
Tripathi et al. 2007
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Molecular Diagnostics
• PCR detection of Xanthomonas campestris pv. musacearum in banana.
– Specific and sensitive primers
• PCR was used to monitor the movement of Xcm along banana pseudostem of a mother plant and its associated suckers.
Adikini et al. 2008
Adikini 2009, Master Thesis
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Field to lab samples for diagnostics
• Sample collection
• FTA
• 2 minute extraction
• PhytoPass sticks
• Silica gel
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Banana
Xanthomonas Wilt
in Kagera district,
Tanzania
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Status of BXW
• Survey of BXW incidence - C3P project
• Developing GIS based tool for forecasting disease spread patterns, diagnosing epidemic phase and response framework guide
• C3P data presented as GIS output to predict impact of BXW on risk to food security and income generation
Uganda:
annual losses of 70 - 200
million US $
2-3 % of GDP
Burundi and Rwanda:
predicted 100 million US $
Uganda:
annual losses of 70 - 200
million US $
2-3 % of GDP
Burundi and Rwanda:
predicted 100 million US $
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Main insects involved: Honey bee, stingless bees, wasps, drosophilids,
Chloropids (internally and externally)
Inoculum Source: bunch (ooze, nectar, sap, fruits)
Transmission: male bud and female inflorescence
Understanding BXW transmission for appropriate management
Distance: transmission of low inoculum quantities at
250m with only 0.4% diseased plants
Bee Propolis: Presence of bacteria and chemical
compound against Xcm
Symptom due to insects
and small birds
Drosophilids on sick
fingers
Honey Bees Wasps Stingless bees
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Understanding BXW transmission for appropriate management
Alternative crops: flowering of palm trees affects bees’ presence/absence
Escaping factors: Nectar presence, quantity/quality; bract and flower
persistence
Altitude: No differences found in insect composition and abundance between
1000masl and 2000masl in DRC
Latent inoculation: banana can successfully grow to maturity when only
relatively low inoculum is transmitted and also through vertical
transmission
Coloration: virulent but orange Xcm colonies are obtained from latent cases
Field recovery: sick fields can be recovered if new infections are avoided
Recovering Field in DRC
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
IITA’s contribution to NARO led ASARECA project with
collaborators from Kenya and DRC
• Generate knowledge on wilt escape trait in relation to cultivars, seasonality and agroecology
• GIS based tool for forecasting disease spread patterns, diagnosing epidemic phase and response framework guide
• Developing improved cost effective tools for lab and field diagnosis of BXW
• Variability of Xanthomonas campetsris pv. musacearum
• Fallow period before replanting in BXW infested field
• Assess and manage risk of cross border BXW spread through trade
• Improving disinfecting technologies for pruning tools
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Unpared corm Pared corm
have wounds,
are more suscept
Corm cured
for 2-3 days
after paring is
less susceptible
TC plants
No root injuries
Top soil
avoid
Subsoil
Less Xcm
Adjustments in planting practices can help
to avoid effect of Xcm in residues and soil
Technologies to support replanting
Mwangi et al. 2007
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Effect of Potassium Nutrition on BXW
• Increased potassium availability for banana reduced disease incidence.
c d e
f g h i j
ba
BXW symptoms on FHIA 17 grown on 0.1K
(a), 0.5K (b), 1K (c) and 2K (d) and on
Kayinja grown on 0.1K (f), 0.5K (g), 1K (h)
and 2K (i). Controls (e) and (j) were
inoculated with sterile distilled water.
Atim et al. 2008
Use of potassium rich mulch
are recommended for testing
in field conditions
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Germplasm Screening
• Screening of germplasm for resistance to BXW
started in Uganda in 2003
• No resistance varieties
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Rapid Technique for Screening Banana
Cultivars for Resistance to Xanthomonas Wilt
• An in vitro screening method was developed using small tissue culture grown plantlets.
• Significant differences was observed in susceptibility among the various banana cultivars.
• No significant difference in pathogenicity was observed between the pathogen isolates.
Tripathi et al. 2008
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Characterization of diversity of Xcm
• Genetic homogeneity among Ugandan
isolates of Xanthomonas campestris
pv. musacearum revealed by RAPD
analysis.
• No significant difference in
pathogenicity.
Odipio 2008, M.Sc. Thesis
Odipio et al. 2009
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Development of BXW resistant varieties
• PFLP (plant ferredoxin-like protein) or
HRAP (HR assisting protein) from
sweet pepper.
– Collaboration with NARO & AATF
– Licence/FTO for genes
– Hundred of lines generated
– Molecular analysis
• PCR & Southern blotting
• RT-PCR & Northern blotting
– Promising results under lab. conditions
– Planning for CFT
Tripathi et al. 2009
Namukwaya et al. 2008
R4D Review 2008
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
CONCLUSIONS
• The recommended measures for BXW management involve a mixture
of approaches combining exclusion, eradication, host resistance, and
protection.
• Although much of the emphasis on BXW has focused on
management options based on information on other bacterial wilt
diseases, more basic and strategic information on the pathogen is
required.
• Some countries such as Uganda and Tanzania have achieved
remarkable success in containing the impact of the disease through a
mix of various management approaches.
• The development of disease resistant banana cultivars remains a high
priority because farmers are reluctant to employ labor-intensive
disease control measures.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Acknowledgements
• Partners/Collaborators
– NARO- Uganda
– KARI- Kenya
– ARD- Tanzania
– INERA- DR Congo
– IRAZ/ISABU-
Burundi
– ISAR- Rwanda
– Makerere University
– Academia Sinica,
Taiwan
– Bioversity
– FAO
– ARIs
– AATF
• Funding support
– Gatsby Charitable
Foundation
– CRS
– USAID
– BecA/CIDA
– DFID
– AATF
– CIALCA
– IITA
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
IITA’s contribution to NARO led ASARECA project with
collaborators from Kenya and DRC
• Generate knowledge on wilt escape trait in relation to cultivars, seasonality and agroecology
• GIS based tool for forecasting disease spread patterns, diagnosing epidemic phase and response framework guide
• Developing improved cost effective tools for lab and field diagnosis of BXW
• Variability of Xanthomonas campetsris pv. musacearum
• Fallow period before replanting in BXW infested field
• Assess and manage risk of cross border BXW spread through trade
• Improving disinfecting technologies for pruning tools
Dynamic reporting – use of updated PRA?
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
• To extension,
researchers
& policy makers
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
A PRA is a dynamic document that states current knowledge
and how this relates to risk
A PRA poses key questions on extension, research and policy
needs
A PRA provides the framework
for contingency planning
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
A PRA provides an assessment of:
• efficacy of control options,
varieties,
husbandry practices
• gaps in knowledge and the
uncertainty these presents
• risk of entry, establishment and
spread across PRA area
• consequence, in terms of
economics,
environmental and social impact
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Questions, comments, discussion?