BIOCHEMICAL AND HEREDITARY STUDIES ON ENZYMES AND GENES CONTROLLING ANTHOCYANIN SYNTHESIS IN APPLES

Crosses between red cultivars produced high frequency of less-colored progeny, while hybridization between non-red cultivars yielded some red-fruited F 1 trees. When harvest was delayed and light intensity increased, both green and yellow cultivars accumulated some anthocyanin with higher UDPGal:flavonoid-3-o-glycosyltransferase (UFGalT) activity in colored areas. Overall, anthocyanin accumulation and UFGalT activity were highly correlated (r = 0.8921, P = 0.0001) in fruit from both parental trees and their F 1 progeny, but UFGalT activity always was relatively high in fruit peel, whether anthocyanin accumulated or not. There were no significant differences in phenylalanine ammonia-lyase or chalcone synthase activities among the cultivars, and they did not change much after hybridization.