Host-pathogen interactions in a mixture composed of 2 resistant varieties.

Each resistant variety (row) corresponds to a single resistance gene (either V1 or V2). There are three possible pathogen genotypes that are able to infect at least one variety (columns): av1/Av2, Av1/av2 and av1/av2 (Av means “avirulent” and av means “virulent”). For instance, av1/av2 means that this pathogen genotype is able to infect both V1 and V2: this is a doubly virulent pathogen. In contrast, av1/Av2 and Av1/av2 cannot infect V2 and V1, respectively, but instead trigger immune priming on V2, and V1, respectively. They are monovirulent pathogen genotypes. We ignore the doubly avirulent (Av1/Av2) pathogen genotype, since it can infect none of the resistant varieties in the mixture, and therefore can not get established in the type of host mixtures considered in this study. The symbol + means infection and the * means priming.