Vitamin C content of potato clones from Korean breeding lines and compositional changes during growth and after storage

Vitamin C is the main vitamin source in potato tubers, and its antioxidant activity is known to benefit human health. To improve the vitamin C content and understand its accumulation patterns, we selected 10 advanced clones with high vitamin C content from 268 clones. The levels of the selected clones ranged from 32.3 to 38.9 mg·100 g−1 fresh weight. Among them, four double-cropping clones with short dormancy were selected for further analysis. The vitamin C content of the potato tubers from six potato clones, including two control cultivars, ‘Dejima’ and ‘Chubaek’, was determined on specific days after planting (DAP) and during development. Developmental stages were categorized by weight: I (5–10 g), II (30–40 g), III (70–80 g), and IV (> 120 g). Vitamin C content was highest 90 DAP and dropped slowly by 100 and 110 DAP. Until 90 DAP, we found that developmental stages I and II showed higher contents of vitamin C; however, there were small differences by developmental stage (I to IV) by 100 and 110 DAP. In conclusion, vitamin C content was higher in younger tubers than in mature tubers, and its content was highest 90 DAP in the selected clones. During storage, vitamin C content significantly declined in all clones. The decrease was highest in H06035-4 and H06085-2 compared to ‘Chubaek’ and ‘Dejima’, and the differences between selected clones and control varieties narrowed after 4 months of storage. When we consider the agronomic characteristics and consistency of high vitamin C content, H06035-4 was selected as a high vitamin C content promising line.