Chemical composition of essential oils and their effects on biochemical parameters in seeds and seedlings of caraway (Carum carvi L.)

We studied the composition of caraway, fennel (Foeniculum vulgare Mill.) and marjoram (Origanum majorana L.) oils and their effects on the biochemical response of caraway (Carum carvi L.). Essential oils obtained by steam distillation of their seeds were analyzed using gas chromatography-mass spectrometry. The main components of caraway, fennel and marjoram oils were : carvone, (E)-anethole and gamma-terpinene, respectively. Caraway seeds and seedlings were subjected to continuous influence of each essential oils present in the air at different concentrations (0.625%, 1.25%, 2.5% and 5% v/v). The contents of proline and total polyphenols were determined in caraway seeds and seedlings after 48 and 240 h, respectively. Additionally, contents of pigments (chlorophyll a, chlorophyll b and carotenoids) were measured in caraway seedlings (240 h after sowing). The proline and polyphenol contents increased in both seeds and seedlings. However, essential oils (except caraway oil) decreased the pigment contents in seedlings. The observed effects increased with the concentration of essential oils. The fennel oil had the strongest allelopathic properties.