Abstract

The Apiaceae family known for vegetable crops rich in essential oils, includes numerous genera of high medicinal and economic value. This study investigates the effects of red and far-red light treatments through the dark period (night-break), on the growth characteristics, essential oil quantity and composition, in Coriandrum sativum L., Anethum graveolens L., and Petroselinum crispum. Treatments began 20 days after sowing, with exposure to red or far-red light for 4 h, nightly, from 10 pm to 2 am. Control plants had no treatment. The plants shoots were harvested after 30 days of treatment. The fresh and dry weight, height, petiole length, internode length, leaf number, leaf area, and total chlorophyll of plant samples were measured. Essential oils were evaluated and then analyzed using gas chromatography–mass spectrometry. The results showed that the red and far-red light led to non-significant increase in fresh and dry weight, plant height, petiole length, leaf number, leaf area, essential oil content, and concentration of individual oil components, while the internode length and total chlorophyll showed a significant increase in all treated plants. Therefore, the controlled use of red light and far-red light may be useful for initiating a response in plants, and enhancing their nutritional value.

Key words: Apiaceae, light, night-break, essential oil constituents.