The Durability of Quantitative Host Resistance and Variability in Pathogen Virulence in the Interaction Between European Grapevine Cultivars and Plasmopara viticola

European grapevine, Vitis vinifera , carries no major resistances against Plasmopara viticola the causal agent of grapevine downy mildew. The introgression quantitative trait loci conferring resistance to P. ( Rpv ) from American and Asian donor species has resulted in a range resistant cultivars. In light perennial nature high evolutionary potential durability this is an important challenge. Durability host variability pathogen virulence may be evaluated by describing interactions between isolates cultivars terms loci. A set 16 carrying different combinations loci, was challenged with five isolates, obtained susceptible or Rpv3.1 + V. Based on severity sporulation, phenotypes might distinguished, which could related presence hormonal responses before during some were compared assess mechanisms underlying Rpv3.1, Rpv10 Rpv12 infection isolates. This paper reports strength commonly used single stacked. derived hosts, GRE Pv 1 GPH 1, able sporulate intensely without triggering necrosis. Moreover, not efficiently halt development -breaking isolate 1. Cultivars however, all Phytohormones implicated basal pathogen, but early defense response, significant observed. isolate-specificity Rpv3 - -mediated suggests that these do result most sustainable resistance. Furthermore, isolate-specific behavior emphasizes need for characterization system . standardized phenotyping assay determine measure durability, strength, resistances. both components pathosystem lead increased understanding mechanisms, beneficial durable deployment genes.