关键词: 血橙, 成熟, 花色苷, 可溶性糖, 有机酸

Abstract: In the present study, the variation in anthocyanin content, soluble sugar, organic acid content and anthocyanin synthesis-related gene expression in Tarocco blood oranges during the ripening period (from Day 200 to Day 324 after flowering) were investigated to study the correlation between anthocyanin accumulation and soluble sugar and organic acid contents. Results showed that anthocyanin content in blood oranges gradually increased during the ripening period. The presence of anthocyanins was detected for the first time in blood orange juice at 261 days after flowering. Rapid accumulation of anthocyanins in blood oranges occurred from Day 276 to Day 293 after flowering, with an increasing rate of 0.55 mg/L per day during this period. 4CL, CHS, F3H, F3’5’H, DFR, ANS, UFGT and GST were the core structural genes that regulate the accumulation of anthocyanins in blood oranges. Ruby was the key transcription factor regulating the biosynthesis of anthocyanins in blood oranges. The positive correlation of anthocyanin content with fructose and glucose contents was extremely significant (P < 0.01), with correlation coefficients of 0.810 and 0.799, respectively. The accumulation of fructose and glucose in blood oranges during the ripening period may be an important reason for the biosynthesis of anthocyanins.

Key words: blood oranges, ripening, anthocyanin, soluble sugar, organic acid