Salt effects on shoot growth and essential oil yield and composition in safflower (Carthamus tinctorius L.)

Salinity effects on growth and essential oil composition of Tunisian safflower (Carthamus tinctorius) shoots grown in hydroponic medium were investigated. Plants treated with 25 mM NaCl showed remarkable morphological modifications and decrease in shoot dry matter. Under 50 and 75 mM NaCl, plants showed a withering and a drastic reduction in dry matter (50% and 70%, respectively). Under NaCl 25 mM, essential oil yield increased significantly (p<0.05) up to 70% and 27% respectively in plants from Tazarka and Kairouan provenances compared with the control. The major compound in Tazarka essential oil was found to be 1,8-cineole (23.5%) followed by methyl eugenol (18.0%), 1-pentadecene (9.1%) and camphene (9.0%). In plants from Kairouan provenance, the major compounds were 1-pentadecene (22.9%), methyl-eugenol (11.8%), linalool (8.1%) and camphene (7.9%). Whatever the origin, the application of 25 mM resulted in remarkable changes in the content and the percentage of the main oil components with the effect being more pronounced in plants from Tazarka.