title: Quantitative plant resistance in cultivar mixtures: wheat yellow rust as a modeling case study.
abstract: Unlike qualitative plant resistance, which confers immunity to disease, quantitative resistance confers only a reduction in disease severity and this can be nonspecific. Consequently, the outcome of its deployment in cultivar mixtures is not easy to predict, as on the one hand it may reduce the heterogeneity of the mixture, but on the other it may induce competition between nonspecialized strains of the pathogen. To clarify the principles for the successful use of quantitative plant resistance in disease management, we built a parsimonious model describing the dynamics of competing pathogen strains spreading through a mixture of cultivars carrying nonspecific quantitative resistance. Using the parameterized model for a wheat-yellow rust system, we demonstrate that a more effective use of quantitative resistance in mixtures involves reinforcing the effect of the highly resistant cultivars rather than replacing them. We highlight the fact that the judicious deployment of the quantitative resistance in two- or three-component mixtures makes it possible to reduce disease severity using only small proportions of the highly resistant cultivar. Our results provide insights into the effects on pathogen dynamics of deploying quantitative plant resistance, and can provide guidance for choosing appropriate associations of cultivars and optimizing diversification strategies.
authors.affiliation: INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207, PRES UNAM, 42 rue Georges Morel, F-49071, Beaucouzé Cedex, France.|AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, F-49045, Angers, France.|Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, F-49045, Angers, France.
authors.forename: Natalia
authors.initials: N
authors.lastname: Sapoukhina
authors.affiliation: INRA, UMR 1349, Institut de Génétique, Environnement et Protection des Plantes - IGEPP , BP 35327, F-35653, Le Rheu Cedex, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Paillard
authors.affiliation: INRA, UMR 1349, Institut de Génétique, Environnement et Protection des Plantes - IGEPP , BP 35327, F-35653, Le Rheu Cedex, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Dedryver
authors.affiliation: INRA, UR1290 BIOGER-CPP, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Claude
authors.initials: C
authors.lastname: de Vallavieille-Pope
mesh_terms: D001487:Basidiomycota; D060467:Disease Resistance / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D013045:Species Specificity; D014908:Triticum / Q000235:genetics* / Q000382:microbiology
keywords: Puccinia striiformis; Triticum aestivum; competition; diversified agroecosystems; quantitative/partial resistance; reaction-diffusion model; wheat yellow (stripe) rust