Wild Solanum species as resistance sources against different pathogens of potato

Resistance screenings against Phytophthora infestans, Globodera pallida Pa2/3 and the viruses PVYN, PLRV, PVM and PVS were performed in 98 accessions belonging to 90 Solanum wild species. Seventy accessions showed resistance or partial resistance to one or several of these pathogens. Among them S. brachistotrichum exhibited combined resistance to nematodes. late blight and some of the viruses evaluated. Only part of the resistances previously found in different wild species could be confirmed, which might be due to the existing variability within species, the use of different pathogen strains or isolates, or to different methodologies for resistance screening. Several new resistance sources, such as S. andreanum, S, maglia, S. doddsii and S. boliviense, are provided for the different pathogens analyzed. These findings demonstrate that within the gene pool of Solanum species, still numerous but in part unexploited resistances are available which could be favourably used in potato breeding.