Glycoalkaloid accumulation during tuber development of early potato cultivars

Abstract

Plants of early potato cultivars were sampled at successive harvests during tuber development and individual tubers were analysed for α-solanine and α-chaconine using high-performance liquid chromatography. Mean tuber total glycoalkaloid concentration (α-solanine plus α-chaconine) per plant decreased with time and statistically significant differences between cultivars were observed in the patterns of decline during tuber growth. The mean tuber ratio of α-chaconine to α-solanine increased during tuber development and was also affected by genotype. Total glycoalkaloid concentration for individual tubers of marketable sizes (up to 50 g fresh weight) exceeded the safety limit of 20 mg per 100 g fresh weight for cultivars Home Guard and British Queen but not for Rocket. These differences were attributable to differences in both rates and patterns of glycoalkaloid accumulation during tuber development, although in all cultivars results were consistent with glycoalkaloid accumulation occurring in the expanding peripheral cell layers of tubers for a considerable period after tuber initiation.