Tuberization in Potato at High Temperatures: Gibberellin Content and Transport from Buds

Abstract

Warm temperatures (35°C day/30°C night) which inhibit tuberization in potato (Solanum tuberosum L., cv. Sebago) increased gibberellin activity in crude extracts from buds, but not from mature leaves, as determined by the lettuce hypocotyl bioassay. Changes in the growth of tubers and stolons indicate the occurrence of basipetal movement of GA3 applied to the terminal bud or a mature leaf. 14C labelling from GA3 or mevalonic acid injected just below the terminal bud was recovered in the lower shoot, stolons and tubers, but the amount transported was greater at cool temperatures (20/15°C). It is concluded that high temperatures promote the synthesis of gibberellin in the buds rather than transport to the stolons.