Abstract:

The changes of flower color, pigment composition during flowering in four varieties of Chimonanthus praecox Link. were studied. The flower color was measured according to the Royal Horticultural Society Colour Chart (RHSCC) and by a NF333 spectrophotometer, respectively. A high performance liquid chromatography (HPLC) with a photodiode array detector (HPLC-PAD) and a HPLC-electrospray ionization-mass spectroscopy (HPLC-ESI-MS) were employed for qualitative and quantitative analysis of anthocyanins and flavonoids. The results indicated that the flower color of each variety showed significant difference during flowering. The chroma (C*) of the both perianths decreased, while the hue angle (h) of the yellow outer perianths increased from yellow to pale yellow, and the red inner perianths decreased from red to dark red. Two anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside) and three flavonols (quercetin 3-O-rutinoside, kaempferol 3-O-rutinoside and quercetin aglycone) were detected in the red inner perianths. The three flavonols in the red inner perianths were also detected in the yellow outer perianths. Cyanidin 3-O-rutinoside was detected from C. praecox petals for the first time. Although the kind of pigments kept unchanged during flowering, the pigment contents showed significant difference. Total flavonols (TF) content decreased rapidly from the alabastrum period to the initial flowering period, and then changed smoothly, while total anthocyanins (TA) content in the red inner perianths kept no remarkable changed.

Key words: Chimonanthus praecox, Flower color, Anthocyanin, Flavonoid, HPLC - PAD, HPLC -ESI-MS