Anthocyanin and chlorophyll content during poinsettia bract development

The concentration of anthocyanins, chlorophyll a and b were quantified during bract development of three differently colored Euphorbia pulcherrima Willd. cultivars (‘Mars White’, ‘Mars Pink’, and ‘Mira Red’) and bract color was colorimetrically determined. Color parameter a* increased from the first analyzed stage of bract development to the subsequent stages in all poinsettia cultivars. Chlorophyll a predominated over chlorophyll b in partially pigmented bracts and a sharp decrease in chlorophyll a content was detected in fully pigmented bracts. Eleven different anthocyanic pigments were identified with the use of high-performance liquid chromatography/mass spectrometry (HPLC/MS). The predominant cyanidin-3-galactoside, cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-glucoside and pelargonidin-3-rutinoside were also detected in white and pink poinsettia bracts. Anthocyanin content levels increased significantly with the transition from partially to fully pigmented bracts in all analyzed cultivars and their accumulation coincided with the arrest of photosynthetic pigments synthesis.

► 11 cyanidin, pelargonidin, and delphinidin based anthocyanins in poinsettia bracts.
► Decrease in chlorophyll content during bract development.
► Increase in individual and total anthocyanins during development.
► Modified bract color described with pigment turnover.