Effect of light exposure on the glycoalkaloid content of Solanum phureja tubers

The individual glycoalkaloid contents of tubers from eleven Solanum phureja genotypes have been determined prior to and following exposure to light. In all genotypes, light exposure resulted in a statistically significant increase in total glycoalkaloid content. In nine of the genotypes studied, this was not only due to an increase in the. levels of the solanidine-based glycoalkaloids, oc-solanine and alpha -chaconine, but also due to the light-induced synthesis of a tomatidenol-based glycoalkaloid, alpha -solamarine. Those genotypes that accumulated alpha -solamarine in their tubers also contained tomatidenol-based glycoalkaloids in their leaves, but only solanidine-based glycoalkaloids were detected in the sprouts.