Effect of salinity on quality and quantity of essential oil components and antioxidant activity in yarrow (Achillea millefolium L.)

This research was aimed to investigate the effect of salinity on quality and quantity of essential oil components and antioxidant activity in Achillea millefolium L. The study was conducted in a completely randomized design in greenhouse, controlled environment, with four treatments including 0 (control), 50, 100 and 150 mM NaCl and four replications per treatment. The essential oil was first extracted and the active components of the essential oil were separated and identified by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) methods. Then, the proline content in fresh leaf and antioxidant activity of methanolic extract were determined. According to the results, the essential oil yield showed a significant increase at 150 mM NaCl. Regarding the essential oil composition, the main compounds were delta-cadinol, trans-beta-farnesene, α-Bisabolol, borneol, caryophyllene oxide, and menthone, showing an increase with increasing salinity. Some compounds such as sabinene, cis-β-ocimene, cis-γ-bisabolene were only detected in control treatment. Menthone, beta-bisabolene, epi-beta-santalene, and 1,8-cineole were only detected in the plants treated with salt. Proline content was increased with increased concentration of NaCl. The results showed that radical scavenging activity and reducing power of yarrow extract increased with increasing of salinity concentration. Our findings suggest that salt stress increases the antioxidant compounds in Achillea millefolium.