Durability of plant disease resistance genes

PyrMos Pyramiding or mixing resistance genes? Using a demo-genetic model dynamics of a virus in an heterogeneous landscape during successive cultural seasons, We investigated whether a set of resistance genes would last longer when stacked into a single plant cultivar (pyramiding) or when deployed individually in regional mosaics (mosaic strategy). Strategy performance depended on the fitness costs of adaptive mutations, epidemic intensity before resistance deployment and landscape connectivity. Mosaics were at least as good as pyramiding strategies in most production situations tested. Pyramiding strategies performed better only with slowly changing virus reservoir dynamics (Djidjou-Demasse, Moury & Fabre).