Preliminarily exploring of the association between sugars and anthocyanin accumulation in apricot fruit during ripening

Anthocyanins, of which the accumulation in some plants is enhanced by sugars, play an important role in peel color variation. The relationship between sugar content and anthocyanin accumulation in apricot fruit has been rarely reported. In the present study, we explored anthocyanin accumulation patterns and its effect on peel color, and analyzed the relationship between sugar content and anthocyanin in 11 apricot cultivars (Prunus armeniaca L.) during fruit ripening. Two kinds of anthocyanins, cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside, were detected in yellow- and orange-peeled cultivars, but not in green- and white-peeled cultivars. The former anthocyanin was the major fruit component and presented in higher content than the latter in all tested cultivars. Fruit with higher anthocyanin content always developed red blush on the skin. The anthocyanin content increased and reached the maximum at fruit commercial or physiological ripening stage and determined skin color of fruit along with increasing carotenoid and decreasing chlorophyll content during ripening. Sugars (sucrose, glucose, fructose, and sorbitol), which may act as signal molecules in anthocyanin synthesis, followed a similar content pattern during fruit ripening and were significantly correlated with anthocyanin content in red-blushed cultivars, but weakly correlated in non-blushed cultivars.