In order to rapidly accumulate and fix desirable characteristics in diploid potato, it is necessary to be able to self-pollinate (or inbreed) them.
However, diploid potato has a genetic system that prevents this. Overcoming this system of "self-incompatibility" (SI) is the first of two major requirements of Fixation-Restitution Breeding. To date, the major result of the DIFFUGAT project is the identification of a "self-compatibility" (SC) gene, widespread in potato, that enables the SI system in potato to be overcome, allowing diploid potatoes to be self-pollinated. Genetic markers have been developed for the SC gene, enabling breeders to use a process called marker assisted selection to propagate the gene in diploid breeding material.