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

Abstract

Crosses between red cultivars produced high frequency of less-colored progeny, while hybridization between non-red cultivars yielded some red-fruited F1 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 F1 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.