Comparison of anthocyanin synthesis of true-to-type 'Tsugaru' apple and its red sport strains

摘要

The effects of light and temperature on anthocyanin accumulation in 'Tsugaru' red sport strains, 'Homei' and 'Misuzu' were compared with true-to-type 'Tsugaru' apple. The fruit of the red sport strains developed their red colour earlier than 'Tsugaru', and 'Homei' contained much more anthocyanin both on the blush side and the shaded side of the fruit on the tree. Both red strains accumulated much more anthocyanin than 'Tsugaru' under white plus ultraviolet light of 280-320 nm (+UV), and under white light (-UV), The responsiveness of 'Homei' to -UV light was greater than that of 'Tsugaru' and 'Misuzu'. The optimum temperature for highest anthocyanin production changed from 15 deg C to 20 deg C with advance of fruit ripening in all strains. There were no clear differences between 'Tsugaru' and red strains for anthocyanin accumulation in response to temperature. Phenylalanine-ammonia lyase (PAL) activity has been investigated in relation with anthocyanin accumulation.