Jueves, 22 Diciembre 2016 16:58

New aspects of the reproductive strategy of the fungus causing Verticillium wilt of olive trees

Escrito por

G.C.-E.L.

Vertigen project involving researchers from the University ceiA3 in Córdoba and two U.S. teams from the Universities of Cornell and Penn Stateis comes to a successful completion

Verticillium wilt is becoming an increasing concern in the olive sector in Spain and other Mediterranean due to severe crop losses and olive grove mortalities. This disease is caused by the soil-borne fungus Verticillium dahliae, is extremely difficult to control and in the last decades, has been the focus of numerous research studies. Indeed, ineffectiveness of preventive or post-infection phytosanitary plant treatments has result in industry moving towards preventive actions and use of varieties resistant to the fungus, an approach which has found the support from the scientific community.

One of the latest and most innovative lines of research was developed within VERTIGEN project, led by ceiA3 researcher at the University of Cordoba Rafael M. Jiménez Díaz and which involved scientists from Cornell University (NY) and Pennsylvania, funded by the MINECO National Plan and cofinanced by EU ERDF. This project has focused on reproductive biology of the fungus, for long considered to be strictly asexual and consequently with high stability and low variability in their populations. However, a broad sampling at different geographical areas in the world has shown that there is much more genetic and pathogenic diversity than one would expect just from asexual reproduction, including a highly virulent defoliant strain in olive and cotton. As part of Vertigen project, more than 300 fungal strains isolated from cotton, olive trees and other crops in Spain, Greece, Israel, Italy, Turkey and the United States thousands genotyped by sequencing, resulting in identification of thousands of single nucleotide polymorphism. This results has opened new questions: Is the fungus using sexual reproduction? Will fungal genetic evolution give rise to new, highly damaging strains, even for the most resistant to Verticillium varieties?

Vertigen results on the first working hypotheses to answer these questions were presented yesterday in a conference in Cordoba with participation of ceiA3 researchers from UCO and the Institute for Sustainable Agriculture (CSIC). The communication was delivered was by Professor Michael G. Milgroom and Prof. Rafael M. Jiménez Díaz, director of the scientific team from Cordoba. Esults have also been published in a large number of scientific journals. “Research cooperation will continue in the coming years to address practical applicatios of the progress achieved”, says Professor Jiménez Díaz, who is already applying for funding for this cooperative project in national and international calls

Referencias: 
- Jiménez-Gasco, M., Malcolm, G.M., Berbegal, M., Armengol, J., and Jiménez-Diaz, R.M. 2014. Complex molecular relationship between Vegetative Compatibility Groups in Verticillium dahliae: VCGs do not always align with clonal lineages. Phytopathology 104 (en prensa).
- Jiménez–Díaz, R. M., Cirulli, M., Bubici, G., Jiménez-Gasco, M. M., Antoniou, P. P., and Tjamos, E. C. 2012. Verticillium wilt: A major threat to olive production. Current status and future prospects for its management. Plant Disease Feature Article 96: 304-329. 
- Jiménez Díaz, R.M. 2013. Integrated management of Verticillium wilt in olives. Keynote 6. 11th International Verticillium Symposium, Koopman, B. and von Tiedeman, A. (Eds.). ISBN: 978-3-941261-12-9. DPG-Verlag. Braunschweig, Alemania.
-Milgroom, M. G., Jiménez-Gasco, M.M, Olivares-García, C., and Jiménez-Díaz, R.M. 2013. New insights on the phylogenetic relationships between strains of Verticillium dahliae. 11th International Verticillium Symposium, Koopman, B. and von Tiedeman, A. (Eds.). ISBN: 978-3-941261-12-9. DPG-Verlag. Braunschweig, Alemania.
Jiménez-Díaz, R.M., Olivares-García, C., Landa, B.B., Jiménez-Gasco, M.M, and Navas-Cortés, J.A. 2011. Region-wide analysis of genetic diversity in Verticillium dahliae populations infecting olive in southern Spain and factors influencing the distribution and prevalence of vegetative compatibility groups and pathotypes. Phytopathology 101: 304-315.
-Collado-Romero, M., Mercado-Blanco, J., Olivares-García, C., and Jiménez-Díaz, R.M. 2008. Phylogenetic analysis of Verticillium dahliae vegetative compatibility groups. Phytopathology 98: 1019-1028.
Referencias: 
- Jiménez-Gasco, M., Malcolm, G.M., Berbegal, M., Armengol, J., and Jiménez-Diaz, R.M. 2014. Complex molecular relationship between Vegetative Compatibility Groups in Verticillium dahliae: VCGs do not always align with clonal lineages. Phytopathology 104 (en prensa).
- Jiménez–Díaz, R. M., Cirulli, M., Bubici, G., Jiménez-Gasco, M. M., Antoniou, P. P., and Tjamos, E. C. 2012. Verticillium wilt: A major threat to olive production. Current status and future prospects for its management. Plant Disease Feature Article 96: 304-329. 
- Jiménez Díaz, R.M. 2013. Integrated management of Verticillium wilt in olives. Keynote 6. 11th International Verticillium Symposium, Koopman, B. and von Tiedeman, A. (Eds.). ISBN: 978-3-941261-12-9. DPG-Verlag. Braunschweig, Alemania.
- Milgroom, M. G., Jiménez-Gasco, M.M, Olivares-García, C., and Jiménez-Díaz, R.M. 2013. New insights on the phylogenetic relationships between strains of Verticillium dahliae. 11th International Verticillium Symposium, Koopman, B. and von Tiedeman, A. (Eds.). ISBN: 978-3-941261-12-9. DPG-Verlag. Braunschweig, Alemania.Jiménez-Díaz, R.M., Olivares-García, C., Landa, B.B., Jiménez-Gasco, M.M, and Navas-Cortés, J.A. 2011. Region-wide analysis of genetic diversity in Verticillium dahliae populations infecting olive in southern Spain and factors influencing the distribution and prevalence of vegetative compatibility groups and pathotypes. Phytopathology 101: 304-315.
- Collado-Romero, M., Mercado-Blanco, J., Olivares-García, C., and Jiménez-Díaz, R.M. 2008. Phylogenetic analysis of Verticillium dahliae vegetative compatibility groups. Phytopathology 98: 1019-1028.
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