Huanglongbing: new epidemic situation in the French West ... · Fonds-Saint-Denis Le Carbet...
1
Conclusion • First report of Candidatus Liberibacter asiaticus in the French West Indies • Disease management needs to especially target the vector psyllid • Synergy between local NPPO & LSV-RAPT Reference laboratory This report raises the importance of plant certification, psyllid population control, and surveillance of territories close to the French West Indies, with regards to the risk that HLB presents to citrus production worldwide. Method Assessment Anses-LSV unit for tropical pest is the National Reference Laboratory on tropical phytopathogenic bacteria and viruses. It has produced and validated HLB detection methods (MOA033), under ISO 17025 accreditation. Based on Li & al. duplex PCR (A2/J5 & GB1/GB3) was assessed on several criteria to detect Las, but also Lam & Laf: • Sensitivity • Specificity • Accuracy • Repetability • Detectability • Processed speed • Transferability • Final score: 6.47 / 7 Midrib excision (Photo by University of Florida) HLB detection scheme from MOA033 Epidemiologicaly active HLB Occurence French West Indies Las was detected in Guadeloupe on March 2012 at Le Moule (East) in a Tahiti lime orchard ( C. latifolia ) and crossed the island in six months. D. citri was detected in 1998, where the control of the the psyllid population has been effective with Tamarixia radiata . Las was detected in Martinique on May 2013 on Tahiti lime ( C. latifolia ) at Bellefontaine (NW / private garden) and at Le Lorrain (NE / orchard). D. citri was detected in 2012 and presents a mean parasitism rate of 70% by Tamarixia radiata . Guadeloupe Martinique Petit-Bourg Petit Canal Pointe-Noire Capesterre-Belle-Eau Anse-Bertrand Port Louis Basse-Terre Baillif Terre-de-Bas Vieux-Fort Lamentin Abymes Sainte-Anne Morne-à-l'Eau Trois-Rivières Désirade Capesterre-de-Marie-Galante Vieux-Habitants Deshaies Bouillante Le Gosier Pointe-à-Pître Terre-de-Haut Goyave Sainte-Rose Le Moule Saint-François Baie-Mahault Saint-Louis Type Orchard (76) Private garden (59) Isolated tree (3) Growing facilities (12) On-site HLB detection 2012 Positives (42) Negatives (33) Observations (75) Forest Scale: 1/400 100 Km 0 4 8 12 Le Lamentin Basse-Pointe Le Prêcheur Grand'Rivière L'Ajoupa-Bouillon Fonds-Saint-Denis Le Carbet Saint-Pierre Le Marigot Le Morne-Rouge Saint-Esprit Rivière-Pilote Ducos Sainte-Luce Bellefontaine Case-Pilote Fort de France Saint Joseph Gros-Morne Les Trois-¤lets Rivière-Salée Les Anses-d'Arlet Le Diamant Le Marin Sainte-Anne Le Vauclin Le François Le Robert La Trinité Le Lorrain On-site HLB Detection 2013: Pending analyses (21) Absence (151) Presence (27) 0 5 10 15 Km Scale: 1:235 500 Results Based on MOA033 Detection and caracterisation of Candidatus Liberibacter asiaticus . BLAST analysis revealed 100% identity with the 50S ribosomal protein subunit L1 (rplA) and L10 (rplJ) and no significant homology to other organisms. Sequence assembly on a reference genome (NC_012985) showed 100% homology. Methodology Since 2012, a total of 450 sites were prospected in Martinique and Guadeloupe, where 20 leaves from 10-30 trees were analyzed. DNA extraction was performed (DNeasy Plant Mini Kit, Qiagen) on fresh or dried leaf midribs, along with negative control midribs (Citrus paradisi “Star Rubis”) and polymerase chain reaction amplification was done with the species-specific primers, A2/J5 (Hocquellet et al. 1999) and GB1/GB3 (Teixeira et al. 2005). Only Las-specific 703 bp amplicons were obtained and 20 (out of 43) were sequenced (Beckman Coulter Genomics, United Kingdom; Genbank accession : KF699074 to KF699093) and blasted against NCBI-nr. Aduld psyllid Diaphorina citri along with nymph producing waxy exudate (Photo by Michael E. Rogers) The Asian citrus psyllid, D. citri , is a sap-sucking, hemipteran bug. It is one of only two confirmed vectors of Huanglongbing, widely distributed in southern Asia and has spread to other citrus growing regions: Middle East, America, and the Caribbean. Currently absent in Europe. Presentation Huanglongbing is an unculturable vascular citrus bacterium transmitted from infected to healthy plants through grafting or by citrus psyllids Diaphorina citri and Trioza erytreae . Three species are associated based on the 16S rDNA sequence analysis: • Candidatus Liberibacter asiaticus (Las) • Ca. L. africanus (Laf) • Ca. L. americanus (Lam) Lobsided Tahiti lime with curved columella (Photo by Caroline Sylvaniélo) Blotchy mottle pattern symptoms (Photos by Gilles Cellier) Severe leaf and fruit drop (Photos by Gilles Cellier) Huanglongbing: new epidemic situation in the French West Indies, caused by Candidatus Liberibacter asiaticus G. Cellier , A. Moreau , N. Cassam, B. Hostachy , Anses - Plant Health Laboratory (LSV), Tropical Pests and Diseases Unit, Saint Pierre, Reunion Island; P. Ryckewaert, Cirad, Le Lamentin, Martinique; L. Aurela, FREDON, Les Abymes, Guadeloupe; R. Picard, FREDON, Ducos, Martinique; K. Lombion , B. Marie , Direction of Food, Agriculture and Forestry, Basse-Terre, Guadeloupe; A. L. Rioualec , P. Huguenin , C. Dalibard , J. Iotti , Direction of Food, Agriculture and Forestry, Fort de France, Martinique. Corresponding author: G. Cellier, [email protected] Distribution map of Candidatus Liberibacter asiaticus (source: EPPO) Guadeloupe: HLB Situation in 2012 ( source: DAAF 971) Martinique: HLB Situation in 2013 ( source: DAAF 972)
Transcript of Huanglongbing: new epidemic situation in the French West ... · Fonds-Saint-Denis Le Carbet...
Conclusion• First report of Candidatus Liberibacter asiaticus in the French West Indies• Disease management needs to especially target the vector psyllid
• Synergy between local NPPO & LSV-RAPT Reference laboratory
This report raises the importance of plant certification, psyllid population control, and surveillance of territories close to the French West Indies, with regards to
the risk that HLB presents to citrus production worldwide.
Method AssessmentAnses-LSV unit for tropical pest is the National Reference Laboratory on tropical phytopathogenic bacteria and viruses. It has produced and validated HLB detection methods (MOA033), under ISO 17025 accreditation.
Based on Li & al. duplex PCR (A2/J5 & GB1/GB3) was assessed on several criteria to detect Las, but also Lam & Laf:
• Sensitivity
• Specificity
• Accuracy
• Repetability
• Detectability
• Processed speed
• Transferability
• Final score: 6.47 / 7
Midrib excision (Photo by University of Florida)
HLB detection scheme from MOA033
Epidemiologicaly active
HLB Occurence
French West Indies
Las was detected in Guadeloupe on March 2012 at Le Moule (East) in a Tahiti lime orchard (C. latifolia) and crossed the island in six months.
D. citri was detected in 1998, where the control of the the psyllid population has been effective with Tamarixia radiata.
Las was detected in Martinique on May 2013 on Tahiti lime (C. latifolia)
at Bellefontaine (NW / private garden) and at Le Lorrain (NE / orchard).
D. citri was detected in 2012 and presents a mean parasitism rate
of 70% by Tamarixia radiata.
Guadeloupe Martinique
Petit-Bourg
Petit Canal
Pointe-Noire
Capesterre-Belle-Eau
Anse-Bertrand
Port Louis
Basse-Terre
Baillif
Terre-de-Bas
Vieux-Fort
Lamentin
AbymesSainte-Anne
Morne-à-l'Eau
Trois-Rivières
Désirade
Capesterre-de-Marie-Galante
Vieux-Habitants
Deshaies
Bouillante
Le GosierPointe-à-Pître
Terre-de-Haut
Goyave
Sainte-Rose
Le Moule
Saint-François
Baie-Mahault
Saint-Louis
TypeOrchard (76)Private garden (59)Isolated tree (3)Growing facilities (12)
On-site HLB detection 2012Positives (42)Negatives (33)Observations (75)
Forest
Scale: 1/400 100Km
0 4 8 12
Le Lamentin
Basse-Pointe
Le Prêcheur
Grand'Rivière
L'Ajoupa-Bouillon
Fonds-Saint-Denis
Le Carbet
Saint-PierreLe Marigot
Le Morne-Rouge
Saint-Esprit
Rivière-Pilote
Ducos
Sainte-Luce
Bellefontaine
Case-PiloteFort de France
Saint Joseph
Gros-Morne
Les Trois-¤letsRivière-Salée
Les Anses-d'ArletLe Diamant Le Marin
Sainte-Anne
Le Vauclin
Le François
Le Robert
La Trinité
Le Lorrain
On-site HLB Detection 2013:Pending analyses (21)Absence (151)Presence (27)
0 5 10 15
KmScale: 1:235 500
ResultsBased on MOA033
Detection and caracterisation of Candidatus
Liberibacter asiaticus.
BLAST analysis revealed 100% identity with the 50S ribosomal protein subunit
L1 (rplA) and L10 (rplJ) and no significant homology
to other organisms.
Sequence assembly on a reference genome (NC_012985) showed
100% homology.
MethodologySince 2012, a total of 450 sites were prospected in Martinique and Guadeloupe, where 20 leaves from 10-30 trees were analyzed. DNA extraction was performed (DNeasy Plant Mini Kit, Qiagen) on fresh or dried leaf midribs, along with negative control midribs (Citrus paradisi “Star Rubis”) and polymerase chain reaction amplification was done with the species-specific primers, A2/J5 (Hocquellet et al. 1999) and GB1/GB3 (Teixeira et al. 2005).
Only Las-specific 703 bp amplicons were obtained and 20 (out of 43) were sequenced (Beckman Coulter Genomics, United Kingdom; Genbank accession : KF699074 to KF699093) and blasted against NCBI-nr.
Aduld psyllid Diaphorina citri along with nymph producing waxy exudate (Photo by Michael E. Rogers)
The Asian citrus psyllid, D. citri, is a sap-sucking, hemipteran bug. It is one of only two confirmed vectors of Huanglongbing, widely distributed in southern Asia and has spread to other citrus growing regions: Middle East, America, and the Caribbean. Currently absent in Europe.
PresentationHuanglongbing is an unculturable vascular citrus bacterium transmitted from infected to healthy plants through grafting or by citrus psyllids Diaphorina citri and Trioza erytreae. Three species are associated based on the 16S rDNA sequence analysis:
• Candidatus Liberibacter asiaticus (Las)• Ca. L. africanus (Laf)• Ca. L. americanus (Lam)
Lobsided Tahiti lime with curved columella
(Photo by Caroline Sylvaniélo)Blotchy mottle pattern symptoms (Photos by Gilles Cellier)
Severe leaf and fruit drop (Photos by Gilles Cellier)
Huanglongbing: new epidemic situation in the French West Indies, caused by Candidatus Liberibacter asiaticusG. Cellier, A. Moreau, N. Cassam, B. Hostachy, Anses - Plant Health Laboratory (LSV), Tropical Pests and Diseases Unit, Saint Pierre, Reunion Island; P. Ryckewaert, Cirad, Le Lamentin, Martinique; L. Aurela, FREDON, Les Abymes, Guadeloupe; R. Picard, FREDON, Ducos, Martinique; K. Lombion, B. Marie, Direction of Food, Agriculture and Forestry, Basse-Terre, Guadeloupe; A. L. Rioualec, P. Huguenin, C. Dalibard, J. Iotti, Direction of Food, Agriculture and Forestry, Fort de France, Martinique. Corresponding author: G. Cellier, [email protected]
Distribution map of Candidatus Liberibacter asiaticus (source: EPPO)
Guadeloupe: HLB Situation in 2012 (source: DAAF 971) Martinique: HLB Situation in 2013 (source: DAAF 972)
