113 results on '"Moralejo, Eduardo"'
Search Results
2. A compartmental model for Xylella fastidiosa diseases with explicit vector seasonal dynamics
- Author
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Giménez-Romero, Àlex, Moralejo, Eduardo, and Matías, Manuel A.
- Subjects
Quantitative Biology - Populations and Evolution - Abstract
The bacterium Xylella fastidiosa (Xf) is mainly transmitted by the spittlebug, Philaenus spumarius, in Europe, where it has caused significant economic damage to olive and almond trees. Understanding the factors that determine disease dynamics in pathosystems that share similarities can help design control strategies focused on minimizing transmission chains. Here we introduce a compartmental model for Xf-caused diseases in Europe that accounts for the main relevant epidemiological processes, including the seasonal dynamics of P. spumarius. The model was confronted with epidemiological data from the two major outbreaks of Xf in Europe, the olive quick disease syndrome (OQDS) in Apulia, Italy, caused by the subspecies pauca, and the almond leaf scorch disease (ALSD) in Majorca, Spain, caused by subspecies multiplex and fastidiosa. Using a Bayesian inference framework, we show how the model successfully reproduces the general field data in both diseases. In a global sensitivity analysis, the vector-plant and plant-vector transmission rates, together with the vector removal rate, were the most influential parameters in determining the time of the infected host population peak, the incidence peak and the final number of dead hosts. We also used our model to check different vector-based control strategies, showing that a joint strategy focused on increasing the rate of vector removal while lowering the number of annual newborn vectors is optimal for disease control., Comment: 18 pages, 8 figures
- Published
- 2022
3. Emergence of a Plant Pathogen in Europe Associated with Multiple Intercontinental Introductions.
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Landa, Blanca B, Castillo, Andreina I, Giampetruzzi, Annalisa, Kahn, Alexandra, Román-Écija, Miguel, Velasco-Amo, María Pilar, Navas-Cortés, Juan A, Marco-Noales, Ester, Barbé, Silvia, Moralejo, Eduardo, Coletta-Filho, Helvecio D, Saldarelli, Pasquale, Saponari, Maria, and Almeida, Rodrigo PP
- Subjects
Genetics ,Infection ,Brazil ,Europe ,Genome ,Bacterial ,Introduced Species ,Plant Diseases ,Whole Genome Sequencing ,Xylella ,Xylella fastidiosa ,emerging disease ,genomic diversity ,outbreaks ,recombination ,quarantine ,Xylella fastidiosa ,Microbiology - Abstract
Pathogen introductions have led to numerous disease outbreaks in naive regions of the globe. The plant pathogen Xylella fastidiosa has been associated with various recent epidemics in Europe affecting agricultural crops, such as almond, grapevine, and olive, but also endemic species occurring in natural forest landscapes and ornamental plants. We compared whole-genome sequences of X. fastidiosa subspecies multiplex from America and strains associated with recent outbreaks in southern Europe to infer their likely origins and paths of introduction within and between the two continents. Phylogenetic analyses indicated multiple introductions of X. fastidiosa subspecies multiplex into Italy, Spain, and France, most of which emerged from a clade with limited genetic diversity with a likely origin in California, USA. The limited genetic diversity observed in X. fastidiosa subspecies multiplex strains originating from California is likely due to the clade itself being an introduction from X. fastidiosa subspecies multiplex populations in the southeastern United States, where this subspecies is most likely endemic. Despite the genetic diversity found in some areas in Europe, there was no clear evidence of recombination occurring among introduced X. fastidiosa strains in Europe. Sequence type taxonomy, based on multilocus sequence typing (MLST), was shown, at least in one case, to not lead to monophyletic clades of this pathogen; whole-genome sequence data were more informative in resolving the history of introductions than MLST data. Although additional data are necessary to carefully tease out the paths of these recent dispersal events, our results indicate that whole-genome sequence data should be considered when developing management strategies for X. fastidiosa outbreaks.IMPORTANCEXylella fastidiosa is an economically important plant-pathogenic bacterium that has emerged as a pathogen of global importance associated with a devastating epidemic in olive trees in Italy associated with X. fastidiosa subspecies pauca and other outbreaks in Europe, such as X. fastidiosa subspecies fastidiosa and X. fastidiosa subspecies multiplex in Spain and X. fastidiosa subspecies multiplex in France. We present evidence of multiple introductions of X. fastidiosa subspecies multiplex, likely from the United States, into Spain, Italy, and France. These introductions illustrate the risks associated with the commercial trade of plant material at global scales and the need to develop effective policy to limit the likelihood of pathogen pollution into naive regions. Our study demonstrates the need to utilize whole-genome sequence data to study X. fastidiosa introductions at outbreak stages, since a limited number of genetic markers does not provide sufficient phylogenetic resolution to determine dispersal paths or relationships among strains that are of biological and quarantine relevance.
- Published
- 2020
4. Linking intercontinental biogeographic events to decipher how European vineyards escaped Pierce's disease
- Author
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MORALEJO, EDUARDO, primary, Gimenez-Romero, Alex, additional, and Matias, Manuel A, additional
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- 2024
- Full Text
- View/download PDF
5. Global predictions for the risk of establishment of Pierce’s disease of grapevines
- Author
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Giménez-Romero, Alex, Galván, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martin, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., and Moralejo, Eduardo
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- 2022
- Full Text
- View/download PDF
6. High-resolution climate data reveals increased risk of Pierce’s Disease for grapevines worldwide
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Giménez-Romero, Àlex, primary, Moralejo, Eduardo, additional, and Matías, Manuel A., additional
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- 2024
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- View/download PDF
7. A Compartmental Model for Xylella fastidiosa Diseases with Explicit Vector Seasonal Dynamics
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Giménez-Romero, Àlex, primary, Moralejo, Eduardo, additional, and Matías, Manuel A., additional
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- 2023
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- View/download PDF
8. Contrasting Patterns of Pierce's Disease Risk in European Vineyards Under Global Warming
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Giménez-Romero, Àlex, primary, Iturbide, Maialen, additional, Moralejo, Eduardo, additional, Gutiérrez, José Manuel, additional, and Matías, Manuel A., additional
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- 2023
- Full Text
- View/download PDF
9. Phylogenetic inference enables reconstruction of a long-overlooked outbreak of almond leaf scorch disease (Xylella fastidiosa) in Europe
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Moralejo, Eduardo, Gomila, Margarita, Montesinos, Marina, Borràs, David, Pascual, Aura, Nieto, Alicia, Adrover, Francesc, Gost, Pere A., Seguí, Guillem, Busquets, Antonio, Jurado-Rivera, José A., Quetglas, Bàrbara, García, Juan de Dios, Beidas, Omar, Juan, Andreu, Velasco-Amo, María P., Landa, Blanca B., and Olmo, Diego
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- 2020
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10. Complete Circularized Genome Resources of Seven Strains of Xylella fastidiosa subsp. fastidiosa Using Hybrid Assembly Reveals Unknown Plasmids
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Velasco-Amo, María Pilar, primary, Arias-Giraldo, Luis F., additional, Román-Écija, Miguel, additional, Fuente, Leonardo De La, additional, Marco-Noales, Ester, additional, Moralejo, Eduardo, additional, Navas-Cortés, Juan A., additional, and Landa, Blanca B., additional
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- 2023
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11. Complete circularized genome resources of seven strains of Xylella fastidiosa subsp. fastidiosa using hybrid assembly reveals unknown plasmids
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European Commission, Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Interprofesional del Aceite de Oliva Español, Consejo Superior de Investigaciones Científicas (España), Ministerio de Agricultura, Pesca y Alimentación y Medio Ambiente (España), Organisation for Economic Co-operation and Development, Velasco-Amo, María Pilar, Arias-Giraldo, Luis F., Ecija, Miguel Roman, Fuente, L. de la, Marco-Noales, E., Moralejo, Eduardo, Navas Cortés, Juan Antonio, Landa, Blanca B., European Commission, Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Interprofesional del Aceite de Oliva Español, Consejo Superior de Investigaciones Científicas (España), Ministerio de Agricultura, Pesca y Alimentación y Medio Ambiente (España), Organisation for Economic Co-operation and Development, Velasco-Amo, María Pilar, Arias-Giraldo, Luis F., Ecija, Miguel Roman, Fuente, L. de la, Marco-Noales, E., Moralejo, Eduardo, Navas Cortés, Juan Antonio, and Landa, Blanca B.
- Abstract
Xylella fastidiosa (Xf) is a vascular plant pathogenic bacterium native to the Americas that is causing significant epidemics and economic losses in olive and almonds in Europe, where it is a quarantine pathogen. Since its first detection in 2013 in Italy, mandatory surveys across Europe revealed the presence of the bacterium also in France, Spain, and Portugal. Combining ONT and Illumina sequencing data, we assembled high-quality complete genomes of seven Xf subsp. fastidiosa strains isolated from different plants in Spain, the USA, and Mexico. Comparative genomic analyses discovered differences in plasmid content among strains, including plasmids that had been overlooked previously when using Illumina sequencing platform alone. Interestingly, in strain CFBP8073, intercepted in France from plants imported from Mexico, three plasmids were identified, including two (plasmid pXF-P1.CFBP8073 and pXF-P2.CFBP8073) not previously described in X. fastidiosa, and one (pXF5823.CFBP8073) almost identical to a plasmid described in a Xf strain from citrus. Plasmids found in the Spanish strains here were similar to those described previously in other strains from the same subspecies and ST1 isolated in the Balearic Islands and the USA. The genome resources from this work will assist in further studies on the role of plasmids in the epidemiology, ecology, and evolution of this plant pathogen.
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- 2023
12. A Compartmental Model for Xylella fastidiosa Diseases with Explicit Vector Seasonal Dynamics
- Author
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Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Giménez-Romero, Alex, Moralejo, Eduardo, Matías, Manuel A., Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Giménez-Romero, Alex, Moralejo, Eduardo, and Matías, Manuel A.
- Abstract
The bacterium Xylella fastidiosa is mainly transmitted by the meadow spittlebug Philaenus spumarius in Europe, where it has caused significant economic damage to olive and almond trees. Understanding the factors that determine disease dynamics in pathosystems that share similarities can help to design control strategies focused on minimizing transmission chains. Here, we introduce a compartmental model for X. fastidiosa-caused diseases in Europe that accounts for the main relevant epidemiological processes, including the seasonal dynamics of P. spumarius. The model was confronted with epidemiological data from the two major outbreaks of X. fastidiosa in Europe, the olive quick disease syndrome in Apulia, Italy, caused by the subspecies pauca, and the almond leaf scorch disease in Mallorca, Spain, caused by subspecies multiplex and fastidiosa. Using a Bayesian inference framework, we show how the model successfully reproduces the general field data in both diseases. In a global sensitivity analysis, the vector-to-plant and plant-to-vector transmission rates, together with the vector removal rate, were the most influential parameters in determining the time of the infectious host population peak, the incidence peak, and the final number of dead hosts. We also used our model to check different vector-based control strategies, showing that a joint strategy focused on increasing the rate of vector removal while lowering the number of annual newborn vectors is optimal for disease control. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
- Published
- 2023
13. A compartmental model forXylella fastidiosadiseases with explicit vector seasonal dynamics
- Author
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Giménez-Romero, Àlex, primary, Moralejo, Eduardo, additional, and Matías, Manuel A., additional
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- 2022
- Full Text
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14. Evaluation of Control Strategies for Xylella fastidiosa in the Balearic Islands
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Quetglas, Bàrbara, primary, Olmo, Diego, additional, Nieto, Alicia, additional, Borràs, David, additional, Adrover, Francesc, additional, Pedrosa, Ana, additional, Montesinos, Marina, additional, de Dios García, Juan, additional, López, Marta, additional, Juan, Andreu, additional, and Moralejo, Eduardo, additional
- Published
- 2022
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15. Phytophthora niederhauserii sp. nov., a polyphagous species associated with ornamentals, fruit trees and native plants in 13 countries
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Abad, Z. Gloria, Abad, Jorge A., Cacciola, Santa Olga, Pane, Antonella, Faedda, Roberto, Moralejo, Eduardo, Pérez-Sierra, Ana, Abad-Campos, Paloma, Alvarez-Bernaola, Luis A., Bakonyi, József, Józsa, András, Herrero, Maria Luz, Burgess, Treena I., Cunnington, James H., Smith, Ian W., Balci, Yilmaz, Blomquist, Cheryl, Henricot, Béatrice, Denton, Geoffrey, Spies, Chris, Mcleod, Adele, Belbahri, Lassaad, Cooke, David, Kageyama, Koji, Uematsu, Seiji, Kurbetli, İlker, and Değirmenci, Kemal
- Published
- 2014
16. Supplementary Information for Global predictions for the risk of establishment of Pierce’s disease of grapevines
- Author
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Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., Moralejo, Eduardo, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., and Moralejo, Eduardo
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- 2022
17. Description of Additional Supplementary Files: Global predictions for the risk of establishment of Pierce's disease of grapevines
- Author
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Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., Moralejo, Eduardo, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., and Moralejo, Eduardo
- Abstract
Supplementary Data 1- Results of the inoculation assays on European grapevine varieties with two isolates of Xylella fastidiosa subsp. fastidiosa (ST1) carried out in Mallorca between 2018 and 2020., Supplementary Data 2- Distribution of Pierce's disease in the United States. Data was obtained from different publications in which at least information of the county was provided., Supplementary Data 3- Pierce's disease risk of establishment in winegrowing regions of China and the Southern Hemisphere., Supplementary Data 4- Pierce's disease risk areas in European vineyards given by the intersection of Corine-Land-Cover and the projected model in the ERA5-land data under a Ro=5 scenario and a spatial heterogeneous vector distribution for 2019 and projection for 2050.
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- 2022
18. Global predictions for the risk of establishment of Pierce's disease of grapevines
- Author
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Govern de les Illes Balears, Ministerio de Ciencia e Innovación (España), European Commission, Agencia Estatal de Investigación (España), Comunidad de Madrid, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., Moralejo, Eduardo, Govern de les Illes Balears, Ministerio de Ciencia e Innovación (España), European Commission, Agencia Estatal de Investigación (España), Comunidad de Madrid, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., and Moralejo, Eduardo
- Abstract
The vector-borne bacterium Xylella fastidiosa is responsible for Pierce's disease (PD), a lethal grapevine disease that originated in the Americas. The international plant trade is expanding the geographic range of this pathogen, posing a new threat to viticulture worldwide. To assess the potential incidence of PD, we have built a dynamic epidemiological model based on the response of 36 grapevine varieties to the pathogen in inoculation assays and on the vectors' distribution when this information is available. Key temperature-driven epidemiological processes, such as PD symptom development and recovery, are mechanistically modelled. Integrating into the model high-resolution spatiotemporal climatic data from 1981 onward and different infectivity (R0) scenarios, we show how the main wine-producing areas thrive mostly in non-risk, transient, or epidemic-risk zones with potentially low growth rates in PD incidence. Epidemic-risk zones with moderate to high growth rates are currently marginal outside the US. However, a global expansion of epidemic-risk zones coupled with small increments in the disease growth rate is projected for 2050. Our study globally downscales the risk of PD establishment while highlighting the importance of considering climate variability, vector distribution, and an invasive criterion as factors to obtain better PD risk maps.
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- 2022
19. Global predictions for the risk of establishment of Pierce’s disease of grapevines
- Author
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Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Govern de les Illes Balears, Comunidad de Madrid, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., Moralejo, Eduardo, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Govern de les Illes Balears, Comunidad de Madrid, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., and Moralejo, Eduardo
- Abstract
The vector-borne bacterium Xylella fastidiosa is responsible for Pierce's disease (PD), a lethal grapevine illness that originated in the Americas. The international plant trade is expanding the geographic range of this pathogen, posing a new threat to viticulture worldwide. To assess the potential incidence of PD, we have built a dynamic epidemiological model based on the response of 36-grapevine varieties to the pathogen in inoculation assays and on the vectors' distribution when this information is available. Key temperature-driven epidemiological processes, such as PD symptom development and recovery, are mechanistically modelled. Integrating into the model high-resolution spatiotemporal climatic data from 1981 onward and different infectivity (R0) scenarios, we show how the main wine-producing areas thrive mostly in non-risk, transient, or epidemic-risk zones with potentially low growth rates in PD incidence. Epidemic-risk zones with moderate to high growth rates are currently marginal outside the United States. However, a global expansion of epidemic-risk zones coupled with small increments in the disease growth rate is projected for 2050. Our study globally downscales the risk of PD establishment while highlighting the importance of considering climate variability, vector distribution and an invasive criterion in obtaining accurate risk maps to guide policy decision-making in plant health.
- Published
- 2022
20. Climate-driven global-risk maps for the establishment of Pierce's Disease of grapevines
- Author
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Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), European Commission, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., Moralejo, Eduardo, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), European Commission, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., and Moralejo, Eduardo
- Abstract
The clonal lineage of the bacterium Xylella fastidiosa (Xf) responsible for Pierce’s disease (PD) poses a threat to viticulture worldwide. Although this vector-transmitted disease has remained mainly restricted to the United States, recent introductions on the islands of Majorca (Spain) and Taiwan have raised concerns about the risk of spreading worldwide. To assess this risk, here we build a climate-driven epidemiological model that simulates PD progression. The model considers the temperature-dependent infection process based on a 3-year inoculation assay and assume local disease propagation when climatic conditions are favourable. The model was successfully validated with spatiotemporal data of the PD distribution in the United States yielding a remarkable ~90% accuracy. Thereafter the model was applied to the main winegrowing regions worldwide, specially focusing in Europe as a case study based on the distribution of the main vector, Philaenus spumarius. Our model simulation reveals that most wine-quality producing areas in China, Europe, Argentina, Chile, South Africa, and Australia currently thrive in non-risk or transient-risk zones. To a lesser extent, epidemic-risk zones with low to moderate risk indices appear in coastal zones such as Mallorca and Apulia, where Xf outbreaks have been already detected. The European case shows how models assuming a vector heterogeneous distribution yield lesser extended epidemic-risk zones than previous risk maps. Overall, a global expansion of PD epidemic-risk zones is projected for 2050, although with low increase in risk indices. Our study highlights the importance of considering climate variability and an invasive criterion to obtain precise risk maps for plant health decision-making.
- Published
- 2022
21. A compartmental model for Xylella fastidiosa diseases with explicit vector seasonal dynamics
- Author
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Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Giménez-Romero, Alex, Moralejo, Eduardo, Matías, Manuel A., Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Giménez-Romero, Alex, Moralejo, Eduardo, and Matías, Manuel A.
- Abstract
The bacterium Xylella fastidiosa (Xf) is mainly transmitted by the spittlebug, Philaenus spumarius, in Europe, where it has caused significant economic damage to olive and almond trees. Understanding the factors that determine disease dynamics in pathosystems that share similarities can help design control strategies focused on minimizing transmission chains. Here we introduce a compartmental model for Xf-caused diseases in Europe that accounts for the main relevant epidemiological processes, including the seasonal dynamics of P. spumarius. The model was confronted with epidemiological data from the two major outbreaks of Xf in Europe, the olive quick disease syndrome (OQDS) in Apulia, Italy, caused by the subspecies pauca, and the almond leaf scorch disease (ALSD) in Majorca, Spain, caused by subspecies multiplex and fastidiosa. Using a Bayesian inference framework, we show how the model successfully reproduces the general field data in both diseases. In a global sensitivity analysis, the vector-plant and plant-vector transmission rates, together with the vector removal rate, were the most influential parameters in determining the time of the infected host population peak, the incidence peak and the final number of dead hosts. We also used our model to check different vector-based control strategies, showing that a joint strategy focused on increasing the rate of vector removal while lowering the number of annual newborn vectors is optimal for disease control.
- Published
- 2022
22. Global predictions for the risk of establishment of Pierce’s disease of grapevines
- Author
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Giménez-Romero, Àlex, primary, Galván, Javier, additional, Montesinos, Marina, additional, Bauzà, Joan, additional, Godefroid, Martin, additional, Fereres, Alberto, additional, Ramasco, José J., additional, Matías, Manuel A., additional, and Moralejo, Eduardo, additional
- Published
- 2022
- Full Text
- View/download PDF
23. Climate-driven global-risk maps for the establishment of Pierce's Disease of grapevines
- Author
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Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martin, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., Moralejo, Eduardo, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), and European Commission
- Subjects
ComputingMethodologies_GENERAL - Abstract
Trabajo presentado en el IFISC Poster Party (online).-- The IFISC Poster Party is an annual activity where PhD students and postdoctoral researchers of IFISC present their research in a poster format.-- Biocomplexity., The clonal lineage of the bacterium Xylella fastidiosa (Xf) responsible for Pierce’s disease (PD) poses a threat to viticulture worldwide. Although this vector-transmitted disease has remained mainly restricted to the United States, recent introductions on the islands of Majorca (Spain) and Taiwan have raised concerns about the risk of spreading worldwide. To assess this risk, here we build a climate-driven epidemiological model that simulates PD progression. The model considers the temperature-dependent infection process based on a 3-year inoculation assay and assume local disease propagation when climatic conditions are favourable. The model was successfully validated with spatiotemporal data of the PD distribution in the United States yielding a remarkable ~90% accuracy. Thereafter the model was applied to the main winegrowing regions worldwide, specially focusing in Europe as a case study based on the distribution of the main vector, Philaenus spumarius. Our model simulation reveals that most wine-quality producing areas in China, Europe, Argentina, Chile, South Africa, and Australia currently thrive in non-risk or transient-risk zones. To a lesser extent, epidemic-risk zones with low to moderate risk indices appear in coastal zones such as Mallorca and Apulia, where Xf outbreaks have been already detected. The European case shows how models assuming a vector heterogeneous distribution yield lesser extended epidemic-risk zones than previous risk maps. Overall, a global expansion of PD epidemic-risk zones is projected for 2050, although with low increase in risk indices. Our study highlights the importance of considering climate variability and an invasive criterion to obtain precise risk maps for plant health decision-making., The authors acknowledge funding from the Spanish Ministry of Science and Innovation through Grants RTI2018-095441-B-C22 (SuMaEco) (AGR and MAM) and RTI2018-093732-B-C22 (PACSS) (JJR) funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, MDM-2017-0711 (AGR, JJR and MAM) funded by MCIN/AEI/10.13039/501100011033
- Published
- 2022
24. Pythium recalcitrans sp. nov. Revealed by Multigene Phylogenetic Analysis
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Moralejo, Eduardo, Clemente, Antonio, Descals, Enrique, Belbahri, Lassaad, Calmin, Gautier, Lefort, François, Spies, Chris F. J., and McLeod, Adele
- Published
- 2008
25. Detection of recombination events in Xylella fastidiosa genomes of different Spanish strains
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Arias-Giraldo Luis F, Potnis Neha, De La Fuente Leonardo, Moralejo Eduardo, Marco-Noales Ester, Velasco-Amo María P, Román-Écija Miguel, Imperial Juan, and Landa Blanca B
- Subjects
xylella ,Plant health ,Xylella ,plant health - Abstract
Trabajo presentado en la 3rd European Conference on Xylella fastidiosa (Building knowledge, protecting plant health), celebrada online el 29 y 30 de abril de 2021., Xylella fastidiosa (Xf) has the capacity of uptaking extracellular DNA from the environment and incorporate it into its genome by homologous recombination, process known as Natural Competence. The process of genetic acquisition and recombination of extracellular DNA could be related to the acquisition of new traits such as antibiotic resistance and virulence factors, giving rise to the origin of new pathotypes. We took a step forward in comparative genomics analysis of Spanish populations of Xf by determining the complete genome of several isolates from Alicante, Mallorca and Ibiza and established potential recombination events that may have occurred with isolates from other places in the world. For this purpose, we used combined Illumina and Oxford Nanopore sequencing platforms and combined assembly approaches to obtain complete circularized genomes. Our results showed that olive and almond isolates belonging to subspecies pauca ST80 from Ibiza (Balearic Islands), the only place where this ST has been detected, showed an unusual level of recombination, being so far the isolates showing the highest number of recombination events among all the Xf isolates sequenced to date. On the order hand, we have confirmed the high degree of homology among genomes from Xf strains from Mallorca and California belonging to subspecies fastidiosa ST1 and subspecies multiplex ST81 isolated from almond and grapes, and we have also identified specific long-size genomic rearrangements in isolates of Xf subspecies multiplex ST6 from Alicante, compared to their homologous strains from the Americas. Research is now underway to determine the source and the functionality of these recombinant genes and their role in pathogenicity.
- Published
- 2021
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26. The challenge of searching for Xylella fastidiosa genetic diversity in its natural habitats
- Author
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Moralejo Eduardo
- Subjects
xylella ,plant health - Abstract
From a mycologist and plant pathologist perspective with little background on prokaryotes, the lifestyle of Xylella fastidiosa (Xf) is still fascinating and enigmatic. In recent years, several studies have largely improved our understanding on the genetic diversity and phylogeny while unraveling the center of origin of the three main Xf subspecies. Yet, surprisingly, these works rely exclusively on isolates collected from human-related environments, i.e., crops, ornamental and landscape plants, out of their native geographic range and mostly from non-native hosts. Such scientific gaps hamper our interpretation on the new advances in the biology of Xf and its vectors. We must therefore recognize the paucity of our knowledge on the ecological niche in its native range and the need to survey in candidate ecosystems such as tropical rain forests of Central and South America. The purpose of this work is to generate debate on how to approach the problem of searching for Xf isolates in natural ecosystems. Although at first glance it might seem an easy task, the challenge requires some previous thoughts. To increase our chances of finding the needle in the haystack, we must ask ourselves what role Xf might have in its natural habitat. This needs a reverse path of ecological inference from the collection of scattered information from the lab and observations in the realized niche. In other words, we need to speculate on the evolutionary ecology of Xf in its natural habitat on the base of what we have. There are many questions and few solid answers about the interspecific interactions, host range, geographic size and population genetics, among other issues. These answers must be integral, cohesive and open-minded because our preconceptions can be wrong. Understanding Xf’s ecological niche in its natural habitat would aid to evaluate future risks and improve our control strategies., ES; PPT; emoralejor@gmail.com
- Published
- 2021
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27. Xylella fastidiosa in the Balearic Islands: a genetic diversity hotspot in Europe
- Author
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Olmo Diego, Nieto Alicia, Borràs David, Pedrosa Ana, Montesinos Marina, García Juan de Dios, Beidas Omar, Juan Andreu, Pascual Aura, and Moralejo Eduardo
- Subjects
xylella ,plant health - Abstract
The Balearic Islands hold one of the major genetic diversity of the pathogen Xylella fastidiosa in Europe. To date four genetic lineages, ST1, ST7, ST 80 and ST81, belonging to the three formally known subspecies, fastidiosa, multiplex and pauca have been detected in the islands. Recently, we have unravelled the origin of two of these introductions in the island of Mallorca, the ST1 of subsp. fastidiosa and the ST81 of subsp. multiplex. They were associated with a long overlooked outbreak of almond leaf scorch disease traced back to 1993 (Moralejo et al. 2020). Less is known about the origin of the ST80 (subsp. pauca) in Ibiza, although there is circumstantial evidence that would indicate it was introduced through the ornamental plant trade at least one decade ago. The ST80 produces a lethal dieback of olive trees; however, they seem less virulent towards olive trees than its counterpart ST53 in Apulia, Italy. Nonetheless, it poses a considerable threat to mainland olive oil production. The other main threat is the ST1 responsible of Pierce’s disease, which is still confined in the island of Mallorca (Moralejo et al. 2019). We used a large database of more than 13,000 samples analysed since 2016 to highlight general aspects of Xylella’s biology, including population genetics, epidemiology, landscape impact, dispersal, phylogenetic signal in host range and disease control. Most of the characteristics related to Pierce’s disease and almond leaf scorch disease repeat those general patterns observed in California, but others seem to be specific to the Balearic Islands., ES; PPT; dolmo@semilla-caib.es
- Published
- 2021
- Full Text
- View/download PDF
28. Studies on the competence of potential Xylella fastidiosa vectors in the Balearic Islands (Spain)
- Author
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Borràs David, Olmo Diego, Nieto Alicia, Pedrosa Ana, García Juan de Dios, Adrover Francisco, Montesinos Marina, Pascual Aura, Moralejo Eduardo, Beidas Omar, and Juan Andreu
- Subjects
xylella ,plant health - Abstract
Since Xylella fastidiosa (Xf) was first detected in Majorca (Balearic Islands) in October 2016, four sequence types (ST) have been described in the Balearic Islands infecting 28 host species. Xf subsp. multiplex (ST 81) is found in Majorca and Minorca and Xf subsp. pauca (ST 80) in Ibiza, whereas Xf subspecies fastidiosa (ST 1) and Xf multiplex (ST7) are only present in Majorca. The bacterium is naturally transmitted by xylem “specialist” insects belonging to the suborder Auchenorrhyncha (Hemiptera). In Italy, Philaenus spumarius (Hemiptera: Aphrophoridae) has been described as main vector of CoDiRO strain (Xf subsp. pauca) in olive orchards, even though recently P. italosignus and Neophilaenus campestris have also been shown to transmit Xf . Studies performed in different orchards from the Balearic Islands revealed that P. spumarius together with N. campestris were the most abundant Aphrophoridae species, being the main candidates for Xf transmission. Transmission tests with P. spumarius and N. campestris were performed to determine the capacity of local populations to transmit Xf subspecies under semi-field conditions (greenhouse). Xf subsp. fastidiosa was transmitted to healthy vines by infected P. spumarius that previously had fed on infected vines and from almond to almond. On the other hand, in crossed-transmission tests P. spumarius was able to transmit Xf subsp. fastidiosa from infected almonds to healthy grapevines and from infected grapevines to almond, and Xf subsp multiplex from wild olive tree to almond trees. Preliminary research has shown that N. campestris can transmit Xf subsp fastidiosa vine to vine., ES; PDF; dborras@semilla-caib.es
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- 2021
- Full Text
- View/download PDF
29. Landscape Epidemiology of Xylella fastidiosa in the Balearic Islands
- Author
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European Commission, Agencia Estatal de Investigación (España), Interprofesional del Aceite de Oliva Español, Ministerio de Agricultura, Pesca y Alimentación (España), Govern de les Illes Balears, Consejo Superior de Investigaciones Científicas (España), Olmo, Diego, Nieto, Alicia, Borrás, David, Montesinos, Marina, Adrover, Francesc, Pascual, Aura, Gost, Pere A., Quetglas, Bàrbara, Urbano, Alejandro, García, Juan de Dios, Velasco-Amo, María Pilar, Olivares-García, Concepción, Beidas, Omar, Juan, Andreu, Marco-Noales, E., Gomila, Margarita, Rita, Juan, Moralejo, Eduardo, Landa, Blanca B., European Commission, Agencia Estatal de Investigación (España), Interprofesional del Aceite de Oliva Español, Ministerio de Agricultura, Pesca y Alimentación (España), Govern de les Illes Balears, Consejo Superior de Investigaciones Científicas (España), Olmo, Diego, Nieto, Alicia, Borrás, David, Montesinos, Marina, Adrover, Francesc, Pascual, Aura, Gost, Pere A., Quetglas, Bàrbara, Urbano, Alejandro, García, Juan de Dios, Velasco-Amo, María Pilar, Olivares-García, Concepción, Beidas, Omar, Juan, Andreu, Marco-Noales, E., Gomila, Margarita, Rita, Juan, Moralejo, Eduardo, and Landa, Blanca B.
- Abstract
Xylella fastidiosa (Xf) is a vascular plant pathogen native to the Americas. In 2013, it was first reported in Europe, implicated in a massive die-off of olive trees in Apulia, Italy. This finding prompted mandatory surveys across Europe, successively revealing that the bacterium was already established in some distant areas of the western Mediterranean. To date, the Balearic Islands (Spain) hold the major known genetic diversity of Xf in Europe. Since October 2016, four sequence types (ST) belonging to the subspecies fastidiosa (ST1), multiplex (ST7, ST81), and pauca (ST80) have been identified infecting 28 host species, including grapevines, almond, olive, and fig trees. ST1 causes Pierce’s disease (PD) and together with ST81 are responsible for almond leaf scorch disease (ALSD) in California, from where they were introduced into Mallorca in around 1993, very likely via infected almond scions brought for grafting. To date, almond leaf scorch disease affects over 81% of almond trees and Pierce’s disease is widespread in vineyards across Mallorca, although producing on average little economic impact. In this perspective, we present and analyze a large Xf-hosts database accumulated over four years of field surveys, laboratory sample analyses, and research to understand the underlying causes of Xf emergence and spread among crops and wild plants in the Balearic Islands. The impact of Xf on the landscape is discussed.
- Published
- 2021
30. Risk of establishment of Pierce's disease in main wine-producer regions worldwide
- Author
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Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., Moralejo, Eduardo, Giménez-Romero, Alex, Galván Fraile, Javier, Montesinos, Marina, Bauzà, Joan, Godefroid, Martín, Fereres, Alberto, Ramasco, José J., Matías, Manuel A., and Moralejo, Eduardo
- Abstract
Pierce’s disease (PD) of grapevines caused by Xylella fastidiosa is currently restricted to North America with a few recent reports in Taiwan and the island of Mallorca in Spain. The underlying biotic and environmental conditions explaining why PD has not spread worldwide remain unexplained. There have been several attempts to predict the climatic conditions suitable for PD using species distribution models. However, few studies have taken into account the distribution of the vectors, an essential factor for accurate risk assessment. Here we first modelled the climatic effects that determine both the development and survival of Xf within the plant. This includes the effect of climatic oscillations in the initial population dynamics of the infected plants under different basic reproductive number scenarios. Secondly, we accounted for the distribution of the main known vector Philaenus spumarius in Europe. We also made predictions in other regions worldwide assuming that the vectors responsible for the disease spreading are abundant enough. The simulation output predicts accurately PD known invaded ranges in the US, Mallorca and Taiwan, and explain the past epidemic patterns in North America. When combined with the distribution of the main vector P. spumarius, the risk for chronic PD in Europe is downscaled to unconnected areas of the Mediterranean coast and islands, with much lower risks in the south Atlantic coast.
- Published
- 2021
31. Detection of recombination events in Xylella fastidiosa genomes of different Spanish strains
- Author
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Arias-Giraldo, Luis F., Neha, Potnis, Fuente, L. de la, Moralejo, Eduardo, Marco-Noales, E., Velasco-Amo, María Pilar, Román Ecija, Miguel, Imperial, Juan, Landa, Blanca B., Arias-Giraldo, Luis F., Neha, Potnis, Fuente, L. de la, Moralejo, Eduardo, Marco-Noales, E., Velasco-Amo, María Pilar, Román Ecija, Miguel, Imperial, Juan, and Landa, Blanca B.
- Abstract
Xylella fastidiosa (Xf) has the capacity of uptaking extracellular DNA from the environment and incorporate it into its genome by homologous recombination, process known as Natural Competence. The process of genetic acquisition and recombination of extracellular DNA could be related to the acquisition of new traits such as antibiotic resistance and virulence factors, giving rise to the origin of new pathotypes. We took a step forward in comparative genomics analysis of Spanish populations of Xf by determining the complete genome of several isolates from Alicante, Mallorca and Ibiza and established potential recombination events that may have occurred with isolates from other places in the world. For this purpose, we used combined Illumina and Oxford Nanopore sequencing platforms and combined assembly approaches to obtain complete circularized genomes. Our results showed that olive and almond isolates belonging to subspecies pauca ST80 from Ibiza (Balearic Islands), the only place where this ST has been detected, showed an unusual level of recombination, being so far the isolates showing the highest number of recombination events among all the Xf isolates sequenced to date. On the order hand, we have confirmed the high degree of homology among genomes from Xf strains from Mallorca and California belonging to subspecies fastidiosa ST1 and subspecies multiplex ST81 isolated from almond and grapes, and we have also identified specific long-size genomic rearrangements in isolates of Xf subspecies multiplex ST6 from Alicante, compared to their homologous strains from the Americas. Research is now underway to determine the source and the functionality of these recombinant genes and their role in pathogenicity.
- Published
- 2021
32. Landscape Epidemiology of Xylella fastidiosa in the Balearic Islands
- Author
-
Olmo, Diego, primary, Nieto, Alicia, additional, Borràs, David, additional, Montesinos, Marina, additional, Adrover, Francesc, additional, Pascual, Aura, additional, Gost, Pere A., additional, Quetglas, Bàrbara, additional, Urbano, Alejandro, additional, García, Juan de Dios, additional, Velasco-Amo, María Pilar, additional, Olivares-García, Concepción, additional, Beidas, Omar, additional, Juan, Andreu, additional, Marco-Noales, Ester, additional, Gomila, Margarita, additional, Rita, Juan, additional, Moralejo, Eduardo, additional, and Landa, Blanca B., additional
- Published
- 2021
- Full Text
- View/download PDF
33. Phylogenetic inference enables reconstruction of a long-overlooked outbreak of almond leaf scorch disease (Xylella fastidiosa) in Europe
- Author
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European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Universidad de Las Islas Baleares, Moralejo, Eduardo, Gomila, Margarita, Montesinos, Marina, Borrás, David, Pascual, Aura, Nieto, Alicia, Adrover, Francesc, Gost, Pere A., Seguí, Guillem, Busquets, Antonio, Jurado-Rivera, José A., Quetglas, Bàrbara, García, Juan de Dios, Beidas, Omar, Juan, Andreu, Velasco-Amo, María Pilar, Landa, Blanca B., Olmo, Diego, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Universidad de Las Islas Baleares, Moralejo, Eduardo, Gomila, Margarita, Montesinos, Marina, Borrás, David, Pascual, Aura, Nieto, Alicia, Adrover, Francesc, Gost, Pere A., Seguí, Guillem, Busquets, Antonio, Jurado-Rivera, José A., Quetglas, Bàrbara, García, Juan de Dios, Beidas, Omar, Juan, Andreu, Velasco-Amo, María Pilar, Landa, Blanca B., and Olmo, Diego
- Abstract
The recent introductions of the bacterium Xylella fastidiosa (Xf) into Europe are linked to the international plant trade. However, both how and when these entries occurred remains poorly understood. Here, we show how almond scorch leaf disease, which affects ~79% of almond trees in Majorca (Spain) and was previously attributed to fungal pathogens, was in fact triggered by the introduction of Xf around 1993 and subsequently spread to grapevines (Pierceʼs disease). We reconstructed the progression of almond leaf scorch disease by using broad phylogenetic evidence supported by epidemiological data. Bayesian phylogenetic inference predicted that both Xf subspecies found in Majorca, fastidiosa ST1 (95% highest posterior density, HPD: 1990–1997) and multiplex ST81 (95% HPD: 1991–1998), shared their most recent common ancestors with Californian Xf populations associated with almonds and grapevines. Consistent with this chronology, Xf-DNA infections were identified in tree rings dating to 1998. Our findings uncover a previously unknown scenario in Europe and reveal how Pierce’s disease reached the continent.
- Published
- 2020
34. Emergence of a Plant Pathogen in Europe Associated with Multiple Intercontinental Introductions
- Author
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European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Interprofesional del Aceite de Oliva Español, California Department of Food and Agriculture, Landa, Blanca B., Castillo, Andreina I., Giampetruzzi, Annalisa, Kahn, Alexandra, Román Ecija, Miguel, Velasco-Amo, María Pilar, Navas Cortés, Juan Antonio, Marco-Noales, E., Barbé, Silvia, Moralejo, Eduardo, Coletta-Filho, Helvecio D., Saldarelli, Pasquale, Saponari, Maria, Almeida, Rodrigo P. P., European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Interprofesional del Aceite de Oliva Español, California Department of Food and Agriculture, Landa, Blanca B., Castillo, Andreina I., Giampetruzzi, Annalisa, Kahn, Alexandra, Román Ecija, Miguel, Velasco-Amo, María Pilar, Navas Cortés, Juan Antonio, Marco-Noales, E., Barbé, Silvia, Moralejo, Eduardo, Coletta-Filho, Helvecio D., Saldarelli, Pasquale, Saponari, Maria, and Almeida, Rodrigo P. P.
- Abstract
Pathogen introductions have led to numerous disease outbreaks in naive regions of the globe. The plant pathogen Xylella fastidiosa has been associated with various recent epidemics in Europe affecting agricultural crops, such as almond, grapevine, and olive, but also endemic species occurring in natural forest landscapes and ornamental plants. We compared whole-genome sequences of X. fastidiosa subspecies multiplex from America and strains associated with recent outbreaks in southern Europe to infer their likely origins and paths of introduction within and between the two continents. Phylogenetic analyses indicated multiple introductions of X. fastidiosa subspecies multiplex into Italy, Spain, and France, most of which emerged from a clade with limited genetic diversity with a likely origin in California, USA. The limited genetic diversity observed in X. fastidiosa subspecies multiplex strains originating from California is likely due to the clade itself being an introduction from X. fastidiosa subspecies multiplex populations in the southeastern United States, where this subspecies is most likely endemic. Despite the genetic diversity found in some areas in Europe, there was no clear evidence of recombination occurring among introduced X. fastidiosa strains in Europe. Sequence type taxonomy, based on multilocus sequence typing (MLST), was shown, at least in one case, to not lead to monophyletic clades of this pathogen; whole-genome sequence data were more informative in resolving the history of introductions than MLST data. Although additional data are necessary to carefully tease out the paths of these recent dispersal events, our results indicate that whole-genome sequence data should be considered when developing management strategies for X. fastidiosa outbreaks.
- Published
- 2020
35. Rethinking the Xylella fastidiosa scenario in the Balearic Islands: what epidemiological, phylogenetic and dendrochronological data tell us
- Author
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Moralejo, Eduardo, Olmo, Diego, Gomila, Margarita, Nieto, Alicia, Montesinos, Marina, Borrás, David, Landa, Blanca B., Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), European Commission, and Govern de les Illes Balears
- Abstract
Trabajo presentado en la 2nd European conference on Xylella fastidiosa (how research can support solutions), celebrada en Ajaccio el 29 y 30 de octubre de 2019., The emergence of Xylella fastidiosa(Xf) in Europe has been dealt as relatively recent introductions from the American continent. While this seems accurate for highly virulent genotypes such as thestrain currently causing the quick olive decline syndrome in Apulia since ca. 2013, less virulent Xf genotypes might have gone undetected for a long time, being confused with drought or fungal disease symptoms under Mediterranean climatic conditions. Indeed, the current widespread incidence and severity of the Pierce’s disease (PD) and Almond Leaf Scorch Disease (ALSD) in Mallorca Island can only be understood in this context of a 20-year introduction scenario. Our current epidemiological, phylogenetic anddendrochronological data onXf strains belonging to subsp. fastidiosaST1, and Xf subsp. multiplexST81, causing Pierce’s disease (PD) and ALSD, respectively, strongly suggest that they were overlooked for decades. Both subspecies were very likely transported from California to Mallorca with infected almond scions around 1995 and subsequently spread throughout the island by the local vector Philaenus spumarius. Our phylogenetic analysis based on WGS of isolates of both subspecies from Mallorca supports their Californian origin. Congruent with this, Xf DNA was consistently detected in the growing rings of infected almond trees from 2006 to the present and occasionally as far back as 1998. In the main focus in Son Carrió more than 50% of the almond trees diedand 90% of trees showed symptoms compatible with ALSD in 2012, but the aetiology of this problem was attributed to fungal trunk diseases, drought or field abandonment. We hypothesise that during the last 20 years, Xf subsp. multiplexST81 isolates have adapted to wild olive trees, widespread on the island, causing a mild dieback, and later on reaching the island of Menorca very likely on infected P. spumariustransported as a hitchhiker on ships moving between the islands., This research was funded by project E-RTA2017-00004-C06 from AEI-INIA Spain and FEDER and received financial support from the Ministry of Agriculture, Fishery and Food (Dirección General de la Sanidad de la Producción Agrària) of Spain and from ‘Govern de les Illes Balears’.
- Published
- 2019
36. Understanding the potential origin and epidemiological consequences of the Spanish outbreaks caused byXylella fastidiosasubspecies multiplex
- Author
-
Landa, Blanca B., Castillo, Almudena, Giampetruzzi, Annalisa, Román Ecija, Miguel, Velasco-Amo, María Pilar, Marco-Noales, E., Moralejo, Eduardo, Saponari, Maria, Navas Cortés, Juan Antonio, Almeida, Rodrigo P. P., European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), and Interprofesional del Aceite de Oliva Español
- Abstract
Trabajo presentado en la 2nd European conference on Xylella fastidiosa (how research can support solutions), celebrada en Ajaccio el 29 y 30 de octubre de 2019., Outbreaks in Europe associated with Xylella fastidiosa(Xf) subspecies multiplex are the most frequent, accounting for the larger number of susceptible plant species (more than 70%), with some host overlap among the different regions. Diverse Sequence Types (ST) have been detected across distinct geographical regions: ST6, ST7 and ST79 in Corsica and PACA region (France), ST7 and ST81 in the Balearic Islands (Spain), ST6 in the province of Alicante and Madrid (mainland Spain), ST7 in the Douro Littoral region (Portugal), and ST87 in the region of Tuscany (northern Italy). In recent years, genetic analysis and pathogenicity tests have provided evidence of biological, ecological and host range diversity among strains of the same subspecies and STs. Draft genomes of 12 Spanish isolates of Xf subsp. multiplex (ST6and ST81) were used for comparative genomic studies with currently available genomes of the same subspecies from France and Italy. Phylogenetic analysis based on core genomes, accessory genomes and single nucleotide polymorphisms indicate that: (i) European outbreaks associated with strains of Xf subsp. multiplex most likely result from distinct independent introductions; (ii) ST6-strains recovered from Spain and France, although sharing the same ST, fell in distinct phylogenetic subgroups; (iii) ST81 strains from the Balearic Islands and ST6 strains from Alicante differentiated in distinct phylogenetic groups (i.e. ST81 isolates are closer to ST6 isolates from California and France than ST6 isolates from Alicante, which in turn are closer to ST7 isolates from the USA and France); (iv) a low number of SNPsare detected among the strains recovered in Alicante, suggesting a recent introduction in the area. Additionally, whereas some recombination events were found among ST81 isolates from Mallorca and ST6 isolates from France with isolates of Xf subsp. fastidiosa ST1 from Mallorca, no evidence of recombination among ST6 isolates from Alicante with other European Xf isolates was found. Pathogenicity tests on the three main Spanish olive cultivars are being conducted with isolates belonging to ST6 and ST81 and compared to Xf subsp. paucaST53 from Italy and ST80 from Ibiza. This work highlights that although the use of MLST approach is a powerful tool for resolving genetic relationships among isolates, the exploration of the whole genomes brings to more comprehensive information that in the future may help to retrieve more robust correlations with the biology and host range of the sequenced isolates. Furthermore, since current European regulation of Xf is based on the subspecies present in each outbreak, these results combined with further pathogenicity tests on main crops may help to establish management and regulation policy standards for the affected areas in Europe., This work has received funding from projects 727987 XF-ACTORS (EU-H2020), E-RTA2017-00004-C06-02 from AEI-INIA Spain and FEDER, and the Spanish Olive Oil Interprofessional.
- Published
- 2019
37. Improving Xylella sampling in Mallorca
- Author
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Perelló, S. M., Nieto, Alicia, Borrás, David, Adrover, Francesc, Gost, Pere A., Montesinos, Marina, Moralejo, Eduardo, Landa, Blanca B., Beidas, Omar, Juan, Andreu, Olmo, Diego, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), European Commission, and Interprofesional del Aceite de Oliva Español
- Abstract
Trabajo presentado en la 2nd European conference on Xylella fastidiosa (how research can support solutions), celebrada en Ajaccio el 29 y 30 de octubre de 2019., Xylella fastidiosawas detected in Majorca in late 2016 (Olmo et al. 2017). Since then, accomplishing EU regulatory, a huge number of samples have been analysed. Poster sessions71| P a g eParticularly, the Mallorca outbreak is different to others in Europe, because of the coexistence of subspecies multiplex(ST81, ST7) in almond trees, olive trees and other species, and subspecies fastidiosa(ST1) in almond trees and grapevine plants among others.As alreadyknown, detection tests of X. fastidiosaare conditioned by the sampling date. However, it is not well known if the optimal dates for sampling are the same for all host species, if it is viable to pool several samples, or if the bacterium can be detected in old wood samples.In this study, we have focused the X. fastidiosamonitoring on almond, grapevines and olive trees. Monthly percentages of positives and average Ct value of more than 2,000 analyses of each of these crops were compared. Overall, we observed that for almond trees the best results were obtained from samples collected from June to August, whereas in grapevine the optimum period was from August to October. In olive trees early spring resulted in the most favourable time for detection, with an increase in Ct and decrease of positive cases in summer.In the assays conducted with pooled almond leaf samples, mixing one infected plant extract with the same volume of up to four negative extracts, showed an average Ct increase of 2.7 cycles, whereas for olive and grapevine samples the Ct increase was > 4 cycles.By default, X. fastidiosais normally analysed in leaf midribs and petioles. We also tested the potential use of wood samples from trunks,sampling different tree rings. Although this sampling procedure is not recommended for routine surveys, it allowed us to establish a potential infection chronology of the number of years since the first infection might have occuredin the Balearic Islands., Study supported by Project E-RTA2017-00004-C06-02 from AEI-INIA Spain and FEDER and the Spanish Olive Oil Interprofessional.
- Published
- 2019
38. Improving Xylella sampling in Mallorca
- Author
-
Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), European Commission, Interprofesional del Aceite de Oliva Español, Perelló, S. M., Nieto, Alicia, Borrás, David, Adrover, Francesc, Gost, Pere A., Montesinos, Marina, Moralejo, Eduardo, Landa, Blanca B., Beidas, Omar, Juan, Andreu, Olmo, Diego, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), European Commission, Interprofesional del Aceite de Oliva Español, Perelló, S. M., Nieto, Alicia, Borrás, David, Adrover, Francesc, Gost, Pere A., Montesinos, Marina, Moralejo, Eduardo, Landa, Blanca B., Beidas, Omar, Juan, Andreu, and Olmo, Diego
- Abstract
Xylella fastidiosawas detected in Majorca in late 2016 (Olmo et al. 2017). Since then, accomplishing EU regulatory, a huge number of samples have been analysed. Poster sessions71| P a g eParticularly, the Mallorca outbreak is different to others in Europe, because of the coexistence of subspecies multiplex(ST81, ST7) in almond trees, olive trees and other species, and subspecies fastidiosa(ST1) in almond trees and grapevine plants among others.As alreadyknown, detection tests of X. fastidiosaare conditioned by the sampling date. However, it is not well known if the optimal dates for sampling are the same for all host species, if it is viable to pool several samples, or if the bacterium can be detected in old wood samples.In this study, we have focused the X. fastidiosamonitoring on almond, grapevines and olive trees. Monthly percentages of positives and average Ct value of more than 2,000 analyses of each of these crops were compared. Overall, we observed that for almond trees the best results were obtained from samples collected from June to August, whereas in grapevine the optimum period was from August to October. In olive trees early spring resulted in the most favourable time for detection, with an increase in Ct and decrease of positive cases in summer.In the assays conducted with pooled almond leaf samples, mixing one infected plant extract with the same volume of up to four negative extracts, showed an average Ct increase of 2.7 cycles, whereas for olive and grapevine samples the Ct increase was > 4 cycles.By default, X. fastidiosais normally analysed in leaf midribs and petioles. We also tested the potential use of wood samples from trunks,sampling different tree rings. Although this sampling procedure is not recommended for routine surveys, it allowed us to establish a potential infection chronology of the number of years since the first infection might have occuredin the Balearic Islands.
- Published
- 2019
39. Rethinking the Xylella fastidiosa scenario in the Balearic Islands: what epidemiological, phylogenetic and dendrochronological data tell us
- Author
-
Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), European Commission, Govern de les Illes Balears, Moralejo, Eduardo, Olmo, Diego, Gomila, Margarita, Nieto, Alicia, Montesinos, Marina, Borrás, David, Landa, Blanca B., Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), European Commission, Govern de les Illes Balears, Moralejo, Eduardo, Olmo, Diego, Gomila, Margarita, Nieto, Alicia, Montesinos, Marina, Borrás, David, and Landa, Blanca B.
- Abstract
The emergence of Xylella fastidiosa(Xf) in Europe has been dealt as relatively recent introductions from the American continent. While this seems accurate for highly virulent genotypes such as thestrain currently causing the quick olive decline syndrome in Apulia since ca. 2013, less virulent Xf genotypes might have gone undetected for a long time, being confused with drought or fungal disease symptoms under Mediterranean climatic conditions. Indeed, the current widespread incidence and severity of the Pierce’s disease (PD) and Almond Leaf Scorch Disease (ALSD) in Mallorca Island can only be understood in this context of a 20-year introduction scenario. Our current epidemiological, phylogenetic anddendrochronological data onXf strains belonging to subsp. fastidiosaST1, and Xf subsp. multiplexST81, causing Pierce’s disease (PD) and ALSD, respectively, strongly suggest that they were overlooked for decades. Both subspecies were very likely transported from California to Mallorca with infected almond scions around 1995 and subsequently spread throughout the island by the local vector Philaenus spumarius. Our phylogenetic analysis based on WGS of isolates of both subspecies from Mallorca supports their Californian origin. Congruent with this, Xf DNA was consistently detected in the growing rings of infected almond trees from 2006 to the present and occasionally as far back as 1998. In the main focus in Son Carrió more than 50% of the almond trees diedand 90% of trees showed symptoms compatible with ALSD in 2012, but the aetiology of this problem was attributed to fungal trunk diseases, drought or field abandonment. We hypothesise that during the last 20 years, Xf subsp. multiplexST81 isolates have adapted to wild olive trees, widespread on the island, causing a mild dieback, and later on reaching the island of Menorca very likely on infected P. spumariustransported as a hitchhiker on ships moving between the islands.
- Published
- 2019
40. Understanding the potential origin and epidemiological consequences of the Spanish outbreaks caused byXylella fastidiosasubspecies multiplex
- Author
-
European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Interprofesional del Aceite de Oliva Español, Landa, Blanca B., Castillo, Almudena, Giampetruzzi, Annalisa, Román Ecija, Miguel, Velasco-Amo, María Pilar, Marco-Noales, E., Moralejo, Eduardo, Saponari, Maria, Navas Cortés, Juan Antonio, Almeida, Rodrigo P. P., European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Interprofesional del Aceite de Oliva Español, Landa, Blanca B., Castillo, Almudena, Giampetruzzi, Annalisa, Román Ecija, Miguel, Velasco-Amo, María Pilar, Marco-Noales, E., Moralejo, Eduardo, Saponari, Maria, Navas Cortés, Juan Antonio, and Almeida, Rodrigo P. P.
- Abstract
Outbreaks in Europe associated with Xylella fastidiosa(Xf) subspecies multiplex are the most frequent, accounting for the larger number of susceptible plant species (more than 70%), with some host overlap among the different regions. Diverse Sequence Types (ST) have been detected across distinct geographical regions: ST6, ST7 and ST79 in Corsica and PACA region (France), ST7 and ST81 in the Balearic Islands (Spain), ST6 in the province of Alicante and Madrid (mainland Spain), ST7 in the Douro Littoral region (Portugal), and ST87 in the region of Tuscany (northern Italy). In recent years, genetic analysis and pathogenicity tests have provided evidence of biological, ecological and host range diversity among strains of the same subspecies and STs. Draft genomes of 12 Spanish isolates of Xf subsp. multiplex (ST6and ST81) were used for comparative genomic studies with currently available genomes of the same subspecies from France and Italy. Phylogenetic analysis based on core genomes, accessory genomes and single nucleotide polymorphisms indicate that: (i) European outbreaks associated with strains of Xf subsp. multiplex most likely result from distinct independent introductions; (ii) ST6-strains recovered from Spain and France, although sharing the same ST, fell in distinct phylogenetic subgroups; (iii) ST81 strains from the Balearic Islands and ST6 strains from Alicante differentiated in distinct phylogenetic groups (i.e. ST81 isolates are closer to ST6 isolates from California and France than ST6 isolates from Alicante, which in turn are closer to ST7 isolates from the USA and France); (iv) a low number of SNPsare detected among the strains recovered in Alicante, suggesting a recent introduction in the area. Additionally, whereas some recombination events were found among ST81 isolates from Mallorca and ST6 isolates from France with isolates of Xf subsp. fastidiosa ST1 from Mallorca, no evidence of recombination among ST6 isolates from Alicante with other European Xf
- Published
- 2019
41. Insights into the epidemiology of Pierce's disease in vineyards of Mallorca, Spain
- Author
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Ministerio de Agricultura, Pesca y Alimentación (España), Govern de les Illes Balears, Fundación la Caixa, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Moralejo, Eduardo, Borrás, David, Gomila, Margarita, Montesinos, Marina, Adrover, Francesc, Juan, Andreu, Nieto, Alicia, Olmo, Diego, Seguí, Guillem, Landa, Blanca B., Ministerio de Agricultura, Pesca y Alimentación (España), Govern de les Illes Balears, Fundación la Caixa, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Moralejo, Eduardo, Borrás, David, Gomila, Margarita, Montesinos, Marina, Adrover, Francesc, Juan, Andreu, Nieto, Alicia, Olmo, Diego, Seguí, Guillem, and Landa, Blanca B.
- Abstract
Xylella fastidiosa (Xf), the causal agent of Pierce's disease (PD), has long been considered a major threat to prosperous European viticulture. In May of 2017, PD was officially detected on a grapevine in Mallorca. To better understand the epidemiology of the first established outbreak of PD in Europe, the disease incidence and severity were assessed, vector transmission experiments were performed, and cultivar responses to Xf infections both in the field and in inoculation experiments were monitored. The genetic structure of Xf local populations was also investigated by multilocus sequence typing analysis, and their whole genome sequences and phylogenetic positions compared with respect to PD strains worldwide. Disease incidence was moderately low (0.07) and highly variable, ranging from 0.0 to 0.99. Its economic impact on wine production was considered low. Vineyards managed under conventional viticulture were significantly less infected than organic farming. Under greenhouse conditions, the insect Philaenus spumarius efficiently transmitted the pathogen from infected to healthy grapevines. In the inoculation experiments, Xf infected, to some degree, 29 of the 30 cultivar × rootstock combinations (n = 239). Cultivars Viura, Gorgollasa and Sauvignon Blanc were the most susceptible ones. All Xf isolates from grapevines belonged to sequence type ST1; they phylogenetically clustered within the Californian ST1 clade, with which they shared a 99.94% identity and the same plasmid. In addition, ST1 caused almond leaf scorch disease, where notably its incidence (0.78) and severity was much higher than PD. The likely reasons for these wide differences are discussed in the context of a 20‐year Xf introduction scenario.
- Published
- 2019
42. Draft Genome Resources of Two Strains of Xylella fastidiosa XYL1732/17 and XYL2055/17 Isolated from Mallorca Vineyards
- Author
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Gomila, Margarita, primary, Moralejo, Eduardo, additional, Busquets, Antonio, additional, Segui, Guillem, additional, Olmo, Diego, additional, Nieto, Alicia, additional, Juan, Andreu, additional, and Lalucat, Jorge, additional
- Published
- 2019
- Full Text
- View/download PDF
43. Intraspecific and within-isolate sequence variation in the ITS rRNA gene region of Pythium mercuriale sp. nov. (Pythiaceae)
- Author
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Belbahri, Lassaad, McLeod, Adèle, Paul, Bernard, Calmin, Gautier, Moralejo, Eduardo, Spies, Chris F. J., Botha, Wilhelm J., Clemente, Antonio, Descals, Enrique, Sánchez-Hernández, Esperanza, and Lefort, Francois
- Abstract
Sixteen Pythium isolates from diverse hosts and locations, which showed similarities in their morphology and sequences of the internal transcribed spacer (ITS) region of their rRNA gene, were investigated. As opposed to the generally accepted view, within single isolates ITS sequence variations were consistently found mostly as part of a tract of identical bases (A-T) within ITS1, and of GT or GTTT repeats within the ITS2 sequence. Thirty-one different ITS sequences obtained from 39 cloned ITS products from the 16 isolates showed high sequence and length polymorphisms within and between isolates. However, in a phylogenetic analysis, they formed a cluster distinct from those of other Pythium species. Additional sequencing of two nuclear genes (elongation factor 1α and β-tubulin) and one mitochondrial gene (nadh1) revealed high levels of heterozygosity as well as polymorphism within and between isolates, with some isolates possessing two or more alleles for each of the nuclear genes. In contrast to the observed variation in the ITS and other gene areas, all isolates were phenotypically similar. Pythium mercuriale sp. nov. (Pythiaceae) is characterized by forming thin-walled chlamydospores, subglobose to obovoid, papillate sporangia proliferating internally and smooth-walled oogonia surrounded by multiple antheridia. Maximum likelihood phylogenetic analyses based on both ITS and β-tubulin sequence data place P. mercuriale in a clade between Pythium and Phytophthora
- Published
- 2017
44. Phytophthora niederhauserii sp. nov., a polyphagous species associated with ornamentals, fruit trees and native plants in 13 countries
- Author
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Abad, Gloria Z., Abad, Jorge A., Cacciola, Santa Olga, Pane, Antonella, Faedda, Roberto, Moralejo, Eduardo, Pérez Sierra, Ana María, Abad Campos, Paloma, Alvarez-Bernaola, Luis A., Bakonyi, József, Jozsa, Andras, Herrero, Maria Luz, Burgess, Treena I., Cunnington, James H., Smith, Ian W., and Balci, Yilmaz
- Subjects
Straminipila ,Oomycetes ,b-tub ,Plant pathogen ,PRODUCCION VEGETAL ,EF-1a ,ITS ,Taxonomy - Abstract
[EN] A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia, Hungary, Israel, Italy, Japan, the Netherlands, Norway, South Africa, Spain, Taiwan, Turkey, the United Kingdom and United States in association with shrubs and herbaceous ornamentals grown mainly in greenhouses. The most prevalent hosts are English ivy (Hedera helix) and Cistus (Cistus salvifolius). The association of the species with acorn banksia (Banksia prionotes) plants in natural ecosystems in Australia, in affected vineyards (Vitis vinifera) in South Africa and almond (Prunus dulcis) trees in Spain and Turkey in addition to infection of shrubs and herbaceous ornamentals in a broad range of unrelated families are a sign of a wide ecological adaptation of the species and its potential threat to agricultural and natural ecosystems. The morphology of the persistent non-papillate ellipsoid sporangia, unique toruloid lobate hyphal swellings and amphigynous antheridia does not match any of the described species. Phylogenetic analysis based on sequences of the ITS rDNA, EF-1a, and b-tub supported that this organism is a hitherto unknown species. It is closely related to species in ITS clade 7b with the most closely related species being P. sojae. The name Phytophthora niederhauserii has been used in previous studies without the formal description of the holotype. This name is validated in this manuscript with the formal description of Phytophthora niederhauserii Z.G. Abad et J.A. Abad, sp. nov. The name is coined to honor Dr John S. Niederhauser, a notable plant pathologist and the 1990 World Food Prize laureate., We thank Dr Michael Coffey at the World Oomycete Genetic Resource (WOC) and World Phytophthora Genetic Resource (WPC) Collections for providing valuable information for this manuscript. We also thank Dr Elaine Davison at Western Australian Department of Agriculture for providing isolate VPRI 32086 to James H. Cunnington. The contribution of Dr Suzanne Spencer at the North Carolina Department of Agriculture and Consumer Services providing isolate PH2424 to Z. Gloria Abad is appreciated. Research in Hungary was supported by the Hungarian Scientific Research Fund (OTKA) grants K61107 and K101914. Research in Scotland was support by the Scottish government. Research in Italy was supported by Italian Ministry of University and Research (MIUR; PRIN 2008). LB is supported by the Swiss State Secretariat for Education and Research (grant reference: SER No. C09.0139) and the European Union for the projects ISEFOR ‘‘Increasing sustainability of European forests: modeling for security against invasive pests and pathogens under climate change (FP7- KBBE-2009-3 call, proposal number 245268) and the COST action FP0801 ‘‘Established and emerging Phytophthora: increasing threats to woodland and forest ecosystems in Europe’’.
- Published
- 2014
45. Diplanetism and microcyclic sporulation in Phytophthora ramorum
- Author
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Moralejo, Eduardo and Descals, Enric
- Abstract
The zoosporic phase of the pathogen Phytophthora ramorum plays a crucial role in the process of plant infection, yet little is known about the fate of zoospores failing to target their hosts. Here, we describe new stages in the life cycle of P. ramorum concerning the in vitro development of monomorphic diplanetism and microcyclic sporulation in free water. Papillate cysts were formed after zoospore suspensions of isolates of the EU1 and NA1 clonal lineages were vortexed. Cysts usually germinated directly forming an emerging tube, or indirectly by releasing a secondary zoospore, which leaves behind an empty cyst with a short evacuation tube. Germinate cysts frequently developed either an appressorium or a microsporangium both terminally. We also observed microcyclic sporulation, i.e. sporangia indirectly germinated by forming a microsporangium, as in microcyclic conidiation of true fungi. Temporal progress of encysted zoospores in solution showed that percentage of germination varied significantly among and within isolates as well as between experiments, suggesting that germination is partly ruled by internal mechanisms. Diplanetism and microcyclic sporulation in P. ramorum may provide a second opportunity for host infection and may increase the chance of long dispersal in moving water. © 2010 Blackwell Verlag GmbH., This research was funded by the European Project RAPRA 502672 (risk analysis for P. ramorum, a recently recognized pathogen threat to Europe and cause of sudden oak death in the USA).
- Published
- 2011
46. Phytophthora niederhauserii sp. nov., a polyphagous species associated with ornamentals, fruit trees and native plants in 13 countries
- Author
-
Universitat Politècnica de València. Departamento de Ecosistemas Agroforestales - Departament d'Ecosistemes Agroforestals, European Commission, Department of Agriculture, Australian Government, North Carolina Department of Agriculture and Consumer Services, Hungarian Scientific Research Fund, Staatssekretariat für Bildung, Forschung und Innovation, Suiza, European Cooperation in Science and Technology, Ministero dell'università e della ricerca, Italia, Abad, Gloria Z., Abad, Jorge A., Cacciola, Santa Olga, Pane, Antonella, Faedda, Roberto, Moralejo, Eduardo, Pérez Sierra, Ana María, Abad Campos, Paloma, Alvarez-Bernaola, Luis A., Bakonyi, József, Jozsa, Andras, Herrero, Maria Luz, Burgess, Treena I., Cunnington, James H., Smith, Ian W., Balci, Yilmaz, Universitat Politècnica de València. Departamento de Ecosistemas Agroforestales - Departament d'Ecosistemes Agroforestals, European Commission, Department of Agriculture, Australian Government, North Carolina Department of Agriculture and Consumer Services, Hungarian Scientific Research Fund, Staatssekretariat für Bildung, Forschung und Innovation, Suiza, European Cooperation in Science and Technology, Ministero dell'università e della ricerca, Italia, Abad, Gloria Z., Abad, Jorge A., Cacciola, Santa Olga, Pane, Antonella, Faedda, Roberto, Moralejo, Eduardo, Pérez Sierra, Ana María, Abad Campos, Paloma, Alvarez-Bernaola, Luis A., Bakonyi, József, Jozsa, Andras, Herrero, Maria Luz, Burgess, Treena I., Cunnington, James H., Smith, Ian W., and Balci, Yilmaz
- Abstract
[EN] A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia, Hungary, Israel, Italy, Japan, the Netherlands, Norway, South Africa, Spain, Taiwan, Turkey, the United Kingdom and United States in association with shrubs and herbaceous ornamentals grown mainly in greenhouses. The most prevalent hosts are English ivy (Hedera helix) and Cistus (Cistus salvifolius). The association of the species with acorn banksia (Banksia prionotes) plants in natural ecosystems in Australia, in affected vineyards (Vitis vinifera) in South Africa and almond (Prunus dulcis) trees in Spain and Turkey in addition to infection of shrubs and herbaceous ornamentals in a broad range of unrelated families are a sign of a wide ecological adaptation of the species and its potential threat to agricultural and natural ecosystems. The morphology of the persistent non-papillate ellipsoid sporangia, unique toruloid lobate hyphal swellings and amphigynous antheridia does not match any of the described species. Phylogenetic analysis based on sequences of the ITS rDNA, EF-1a, and b-tub supported that this organism is a hitherto unknown species. It is closely related to species in ITS clade 7b with the most closely related species being P. sojae. The name Phytophthora niederhauserii has been used in previous studies without the formal description of the holotype. This name is validated in this manuscript with the formal description of Phytophthora niederhauserii Z.G. Abad et J.A. Abad, sp. nov. The name is coined to honor Dr John S. Niederhauser, a notable plant pathologist and the 1990 World Food Prize laureate.
- Published
- 2014
47. Phytophthora niederhauserii sp. nov., a polyphagous species associated with ornamentals, fruit trees and native plants in 13 countries
- Author
-
Abad, Z Gloria., Moralejo, Eduardo, Degirmenci, Kemal, Abad, Z Gloria., Moralejo, Eduardo, and Degirmenci, Kemal
- Abstract
A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia, Hungary, Israel, Italy, Japan, the Netherlands, Norway, South Africa, Spain, Taiwan, Turkey, the United Kingdom and United States in association with shrubs and herbaceous ornamentals grown mainly in greenhouses. The most prevalent hosts are English ivy (Hedera helix) and Cistus (Cistus salvifolius). The association of the species with acorn banksia (Banksia prionotes) plants in natural ecosystems in Australia, in affected vineyards (Vitis vinifera) in South Africa and almond (Prunus dulcis) trees in Spain and Turkey in addition to infection of shrubs and herbaceous ornamentals in a broad range of unrelated families are a sign of a wide ecological adaptation of the species and its potential threat to agricultural and natural ecosystems. The morphology of the persistent non-papillate ellipsoid sporangia, unique toruloid lobate hyphal swellings and amphigynous antheridia does not match any of the described species. Phylogenetic analysis based on sequences of the ITS rDNA, EF-1a, and b-tub supported that this organism is a hitherto unknown species. It is closely related to species in ITS clade 7b with the most closely related species being P. sojae. The name Phytophthora niederhauserii has been used in previous studies without the formal description of the holotype. This name is validated in this manuscript with the formal description of Phytophthora niederhauserii Z.G. Abad et J.A. Abad, sp. nov. The name is coined to honor Dr John S. Niederhauser, a notable plant pathologist and the 1990 World Food Prize laureate. © 2014 by The Mycological Society of America.
- Published
- 2014
48. Susceptibility of Iberian trees to Phytophthora ramorum and P. cinnamomi
- Author
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Moralejo, Eduardo, García-Muñoz, J.A., Descals, Enric, Moralejo, Eduardo, García-Muñoz, J.A., and Descals, Enric
- Abstract
The capacity of Phytophthora ramorum to colonize the inner bark of 18 native and two exotic tree species from the Iberian Peninsula was tested. Living logs were wound-inoculated in a growth chamber with three isolates belonging to the EU1 and two to the NA1 clonal lineages of P. ramorum. Most of the Quercus species ranked as highly susceptible in experiments carried out in summer, with mean lesion areas over 100 cm2 in Q. pubescens, Q. pyrenaica, Q. faginea and Q. suber and as large as 273 cm2 in Q. canariensis, ca. 40 days after inoculation. Quercus ilex ranked as moderately susceptible to P. ramorum, forming lesions up to 133 cm2 (average 17·2 cm 2). Pinus halepensis and P. pinea were highly susceptible, exhibiting long, narrow lesions; but three other pine species, P. pinaster, P. nigra and P. sylvestris, were resistant to slightly susceptible. No significant difference in aggressiveness was found between the isolates of P. ramorum. In addition, there was evidence of genetic variation in susceptibility within host populations, and of significant seasonal variation in host susceptibility in some Quercus species. The results suggest a high risk of some Iberian oaks to P. ramorum, especially in forest ecosystems in southwestern Spain, where relict populations of Q. canariensis grow amongst susceptible understory species such as Rhododendron ponticum and Viburnum tinus. One isolate of P. cinnamomi used as positive control in all the inoculations was also highly aggressive to Iberian oaks and Eucalyptus dalrympleana. © 2008 BSPP.
- Published
- 2009
49. Multiple alien Phytophthora taxa discovered on diseased ornamental plants in Spain
- Author
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Moralejo, Eduardo, Pérez Sierra, Ana María, Álvarez, L. A., Belbahri, Lassaad, Lefort, François, Descals, Enric, Moralejo, Eduardo, Pérez Sierra, Ana María, Álvarez, L. A., Belbahri, Lassaad, Lefort, François, and Descals, Enric
- Abstract
The plant trade is unwittingly accelerating the worldwide spread of well-known and new or undescribed Phytophthora species and creating novel niches for emerging pathogens. The results of a survey carried out from 2001 to 2006 in garden centres and nurseries of the Balearic Islands and eastern Spain combined with the analysis of samples received from ornamental nurseries from northern Spain reflected the extent of this global issue at the local scale. A total of 125 Phytophthora isolates were obtained from 37 different host species and 17 putative species identified on morphological features and direct sequencing of the internal transcribed spacer and four mitochondrial and nuclear genes. Five species, P. ramorum, P. hedraiandra, P. 'niederhauserii', P. 'kelmania' and P. 'taxon Pgchlamydo' were formally unknown to science prior to 2001. In addition, 37 new host/pathogen combinations were first records for Spain, highlighting the risk of non-coevolved organisms from different biogeographic origins coming into contact under managed environments. The problem generated by new or rare taxa of Phytophthora found in nurseries for which no prior information on natural habitat and ecology is available for pest risk analysis is discussed. © 2008 The Authors.
- Published
- 2009
50. Strawberry tree blight in Spain, a new disease caused by various Phytophthora species
- Author
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Moralejo, Eduardo, Belbahri, Lassaad, Calmin, Gautier, García-Muñoz, J.A., Lefort, François, Descals, Enric, Moralejo, Eduardo, Belbahri, Lassaad, Calmin, Gautier, García-Muñoz, J.A., Lefort, François, and Descals, Enric
- Abstract
During surveys for Phytophthora ramorum in garden centres in Majorca, Spain, 31 isolates of Phytophthora were recovered from potted strawberry trees (Arbutus unedo) showing leaf and twig blights. Many isolates of Phytophthora syringae and Phytophthora citrophthora as well as single isolates of P. ramorum, Phytophthora tropicalis and Phytophthora nicotianae were identified on morphological features and on the sequences of the internal transcribed spacer regions from ribosomal DNA genes. Phytophthora syringae was collected most frequently in late autumn and winter, whereas P. citrophthora was dominant during late summer and autumn. In vitro pathogenicity of P. syringae and P. citrophthora was compared with that of P. ramorum by inoculating intact detached leaves of A. unedo with zoospores and twigs with mycelial plugs. In addition, in vitro sporangial production was examined on inoculated excised leaves and on agar plugs at 12, 15 and 20°C. Phytophthora citrophthora produced the largest lesions both on leaves and on twigs at all temperatures. Phytophthora ramorum formed lesions comparable in size to those of P. syringae, but it significantly produced more sporangia on excised leaves and agar plugs. In a log inoculation assay, P. syringae caused large lesions in the inner bark, whereas those of P. ramorum were moderate. Strawberry tree blight has not yet been observed in natural ecosystems in the western Mediterranean areas. Possible biological and environmental limitations hindering disease spread in the wild are discussed. © 2008 The Authors.
- Published
- 2008
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