Marker-Assisted Selection for Disease Resistance in Potato Breeding in the Ural Region of Russia (2018–2025): Comprehensive Genotyping and Validation of Key Resistance Markers

Marker-assisted selection (MAS) is a key tool in modern potato breeding for developing resistant varieties. This study aimed to evaluate the efficiency of molecular markers for selecting resistance to major pathogens in Ural (Russian Federation) potato breeding material. From 2018 to 2025, a total of 1212 hybrids and varieties were genotyped using 12 SCAR (sequence-characterized amplified regions) markers associated with resistance to potato wart (<i>Synchytrium endobioticum</i>), late blight (<i>Phytophthora infestans</i>), cyst nematodes (<i>Globodera</i> spp.), and viruses (PVX, PVY). The most frequent markers were TG689, N127, N195, and NL25. Phenotypic validation on more than 100 hybrids confirmed strong predictive power for NL25, TG689, and N195 markers in selecting resistance to wart disease and nematodes. In contrast, markers Rpi-blb1 and Rpi-sto1 for late blight did not show significant associations in this population. The results demonstrate the high diagnostic value of NL25, TG689, and N195 markers for MAS in Ural breeding programs, supporting their use for efficient selection of resistant genotypes.