Resistance to Late Blight in Potato

This chapter presents a summary of research on potato's resistance to its most devastating pathogen, Phytophthora infestans. The chapter begins by focusing on the infamous emergence of potato late blight in Europe. It continues with the history of breeding potatoes resistant to this disease that began soon afterwards. The chapter then discusses changing trends in breeding, from the introduction of qualitative resistance, through the elimination of qualitative resistance in favor of quantitative resistance, then to the coming back into fashion of major resistance (R) genes. Also reviewed are the species from the Solanum genus that are exploited in potato breeding as sources of resistance to late blight. Finally, the chapter talks about quantitative resistance loci (QTLs), when they overlap with the positions of the R genes.