Variation in flavonoid pattern in leaves and flowers of Primula veris of different origin and impact of UV-B

• Primula veris plants were grown in a common garden and differently exposed to UV.
• Phenolic compounds were measured in both young leaves and flowers.
• We found distinct flavonoids discriminating plants of different origin.
• These flavonoids may be useful biomarkers.
• UV had no effects on total but on individual flavonoid concentrations.

Flavonoids can serve as chemotaxonomic markers and play an important role in protection against ultraviolet (UV) radiation. Primula veris originating from two natural field sites in Albania and one cultivar from Austria were used to investigate whether flavonoid pattern may differ between populations and to determine their response to UV. Plants were grown in a common environment and shortly before flowering transferred in two greenhouses with 80% and 4% UV-B transmission, respectively. After two weeks, young leaves and open flowers were harvested and flavonoids analyzed by high performance liquid chromatography. The flavonoid profiles of leaves and flowers were highly distinct for each population, with certain flavonoids occurring only in plants of particular field sites. These flavonoids may be useful biomarkers to identify the origin of plant material. The differences in UV-treatment at that stage had no effect on the total flavonoid contents of both leaves and flowers. However, individual flavonoids of both leaves and flowers responded sensitively to UV, suggesting that they may be involved in protection against UV.