Phenolic Accumulation in Hybrid Primrose and Pigment Distribution in Different Flower Segments

Abstract

Detailed anthocyanin and flavonol profiles were investigated in three flower segments of four different hybrid primrose (Primula ×polyantha) cultivars, and individual compounds were identified using high-performance liquid chromatography (HPLC)/mass spectrometry system. Chlorophyll a and b and total carotenoids were evaluated spectrophotometrically in the corolla tube (CT), and distal and proximal flower segments, and the color of each segment was assessed with a colorimeter. Chlorophyll b predominated over chlorophyll a in all flower segments, and the highest total chlorophyll levels were found in the CTs. Sixteen different anthocyanins (glycosides of cyanidin, delphinidin, peonidin, petunidin, malvidin, and rosinidin) were identified in red, pink, and blue flower extracts. Distal segments of the red hybrid and proximal segments of the pink hybrid accumulated highest levels of total anthocyanins, and no red pigments were detected in yellow-flowered hybrid primrose. Six groups of flavonols (40 individual compounds in total) were detected in different flower segments of four hybrid primrose cultivars. Yellow primrose was characterized by the greatest diversity of flavonols as it contained four isorhamnetin, five kaempferol, six laricitrin, three myricetin, six quercetin, and six syringetin glycosides. On the other hand, the smallest variety of flavonols was detected in pink hybrids. Total phenolic content (TPC) was lowest in the CT (yellow > red > pink), significantly higher in the proximal flower segment (yellow > red > pink), and highest in the distal part of the primrose petal (yellow > pink > red).