LABORATORY ASSESSMENT OF SOME POTATO GENOTYPES WITH POTENTIAL RESISTANCE TO LATE BLIGHT DISEASE (PHYTOPHTHORA INFESTANS)

Late blight (Phytophthora infestans) of potato is considered one of the most devastating plant diseases in the world. Most cultivated potatoes are susceptible to this disease. To NIRDPSB Brasov thirteen potato genotypes (leaves and tubers) were evaluated in laboratory conditions for phenotypic scoring against late blight. Isolates were collected from the greenhouse and inoculated with a complex race of late blight differentials (R1-R11). The best results both at the leaf and tuber level were obtained with the genotypes Sasa (R3) x Rustic (Cl1), Agria x Rustic (Cl 1), Sasa x Fribel and Sasa x Florice which provided a durable source of resistance and can be used in a future breeding program. Instead, the genotypes Sasa (R6) x Orchestra, Sasa (R8) x Orchestra, Sasa (R3) x Orchestra, Sasa (R7) x Orchestra showed sensitivity to the action of the pathogen.