Effect of host allelic dosage on Triticum aestivum-Puccinia recondita specific interaction

Allelic dosage changes in host-pathogen interactions (Triticum aestivum–Puccinia recondita) explain different situations where resistance or susceptibility is observed. Remarkably, the prediction of an interaction change (from compatible to incompatible) by increasing single host allelic dosage is confirmed. Cases of more lasting resistance could also be explained on the basis of these dosage effects. In addition a parallel between specific and nonspecific resistance is established pointing out their basic differences in expression with respect to allelic dosage effects. These situations, together with new possibilities for breeding arising from this knowledge, are discussed.