Genetic discontinuities and disequilibria in recently established populations of the plant pathogenic fungus Mycosphaerella fijiensis
2010
Halkett, Fabien | Coste, D. | Rivas Platero, G.G. | Zapater, Marie-Françoise | Abadie, Catherine | Carlier, Jean | Interactions Arbres-Microorganismes (IAM) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Biologie et Génétique des Interactions Plante-Parasite (UMR BGPI) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro) | Centro Agronomico Tropical de Investigacion y Enseñanza (CATIE) | Biologie et Génétique des Interactions Plantes-Agents Pathogènes ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure Agronomique de Montpellier (ENSA M)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
International audience
Mostrar más [+] Menos [-]Inglés. Dispersal processes of fungal plant pathogens can be inferred from analysis of spatial genetic structures resulting from recent range expansion. The relative importance of long-distance dispersal (LDD) events vs. gradual dispersal in shaping population structures depends on the geographical scale considered. The fungus Mycosphaerella fijiensis, pathogenic on banana, is an example of a recent worldwide epidemic. Founder effects in this species were detected at both global and continental scale, suggesting stochastic spread of the disease through LDD events. In this study, we analysed the structure of M. fijiensis populations in two recently (∼1979–1980) colonized areas in Costa Rica and Cameroon. Isolates collected in 10–15 sites distributed along a ∼250- to 300- km-long transect in each country were analysed using 19 microsatellite markers. We detected low-to-moderate genetic differentiation among populations in both countries and isolation by distance in Cameroon. Combined with historical data, these observations suggest continuous range expansion at the scale of banana-production area through gradual dispersal of spores. However, both countries displayed specific additional signatures of colonization: a sharp discontinuity in gene frequencies was observed along the Cameroon transect, while the Costa Rican populations seemed not yet to have reached genetic equilibrium. These differences in the genetic characteristics of M. fijiensis populations in two recently colonized areas are discussed in the light of historical data on disease spread and ecological data on landscape features.
Mostrar más [+] Menos [-]Palabras clave de AGROVOC
Información bibliográfica
Este registro bibliográfico ha sido proporcionado por Institut national de la recherche agronomique