Cultivar Improvement with Exotic Germplasm: An Example from Potato

Potato breeders have abundant germplasm resources at their disposal in wild relatives and landrace varieties. Exotic germplasm has been used mainly for disease resistance and processing quality genes. Linkage drag is common when introgressing wild germplasm, with poor adaptation and high glycoalkaloid levels commonly observed in hybrid offspring. Poor tuber type, late maturity, and short tuber dormancy accompany desirable traits introduced from landraces. More targeted introgression of exotic genes for potato improvement is needed in future breeding efforts. Potato programs worldwide are exploring the conversion of potato into a diploid inbred-hybrid crop. Backcrossing in this system would allow valuable genes from exotic sources to be fixed in high-performing cultivated potato backgrounds. This offers exciting new possibilities for contributions of wild and cultivated potato relatives to potato cultivar improvement.