Potato Glycoalkaloids, Past Present and Future

The steroidal glycoalkaloids are naturally occurring specialty metabolites of questionable desirability in the vegetable crop, potato. Although glycoalkaloids undoubtedly originated under selection as feeding deterrents against herbivorous pests, they no longer function as the primary feeding deterrent. Moreover, due to their potential toxicity, guidelines persist as to the maximal allowable concentrations for newly developed cultivars. The origins of the glycoalkaloids lie in the ancient relatives of the modern potato, which continue to be used in breeding programs because of the wealth of genetic diversity for performance, nutrition and disease resistance. In recent years, the genes encoding the enzymatic steps responsible for glycoalkaloid synthesis have begun to be elucidated. This in turn has presented the possibility of manipulating these genes to control glycoalkaloid accumulation and increase the availability of diverse biological resources for the development of new and improved cultivars with enhanced agronomic, processing and nutritional characteristics. This article will discuss the origin and diversity of glycoalkaloids in the potato, why they are a concern and what is being done about them, and how the advancement of biological information and technologies will impact potato glycoalkaloids in the future. _____________________________________________________________________________________________________________