title: Epidemiological and evolutionary management of plant resistance: optimizing the deployment of cultivar mixtures in time and space in agricultural landscapes.
abstract: The management of genes conferring resistance to plant-pathogens should make it possible to control epidemics (epidemiological perspective) and preserve resistance durability (evolutionary perspective). Resistant and susceptible cultivars must be strategically associated according to the principles of cultivar mixture (within a season) and rotation (between seasons). We explored these questions by modeling the evolutionary and epidemiological processes shaping the dynamics of a pathogen population in a landscape composed of a seasonal cultivated compartment and a reservoir compartment hosting pathogen year-round. Optimal deployment strategies depended mostly on the molecular basis of plant-pathogen interactions and on the agro-ecological context before resistance deployment, particularly epidemic intensity and landscape connectivity. Mixtures were much more efficient in landscapes in which between-field infections and infections originating from the reservoir were more prevalent than within-field infections. Resistance genes requiring two mutations of the pathogen avirulence gene to be broken down, rather than one, were particularly useful when infections from the reservoir predominated. Combining mixture and rotation principles were better than the use of the same mixture each season as (i) they controlled epidemics more effectively in situations in which within-field infections or infections from the reservoir were frequent and (ii) they fulfilled the epidemiological and evolutionary perspectives.
authors.affiliation: UMR 1065 Unité Santé et Agroécologie du Vignoble, INRA Villenave d'Ornon Cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Fabre
authors.affiliation: Biocore Team, INRIA Sophia Antipolis, France ; UMR 1355 Institut Sophia Agrobiotech, INRA Sophia Antipolis, France ; UMR 7254 Institut Sophia Agrobiotech, Université Nice Sophia Antipolis Sophia Antipolis, France ; UMR 7254 Institut Sophia Agrobiotech, CNRS Sophia Antipolis, France ; UR 407 Pathologie Végétale, INRA Montfavet, France.
authors.forename: Elsa
authors.initials: E
authors.lastname: Rousseau
authors.affiliation: Biocore Team, INRIA Sophia Antipolis, France ; UMR 1355 Institut Sophia Agrobiotech, INRA Sophia Antipolis, France ; UMR 7254 Institut Sophia Agrobiotech, Université Nice Sophia Antipolis Sophia Antipolis, France ; UMR 7254 Institut Sophia Agrobiotech, CNRS Sophia Antipolis, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Mailleret
authors.affiliation: UR 407 Pathologie Végétale, INRA Montfavet, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Moury
keywords: evolutionary epidemiology; functional connectivity; heterogeneity of selection; landscape epidemiology; mosaic strategy; qualitative resistance; resistance durability; rotation strategy