measurementAnthocyanin contents were measured according to the methodof Nakatsuka et al. (2008) with some modifications: 300 mg petaltissues were ground in liquid nitrogen and the anthocyanins wereextracted with 1 mL of 1% (v/v) HCl methanol solution for 24 h at4◦C. After clearing the extractions by centrifugation at 13,000 × gfor 30 min, the supernatant was analyzed with a Beckman DU-800 spectrophotometer (Beckman Instruments, Fullerton, CA). Theabsorbance of the extract at 530 nm was used as a measure of theanthocyanin contents; values were normalized to the fresh weightof each sample to indicate anthocyanin content. Anthocyanin con-tent was determined on three replicates (each of one flower)