The Effect of Photoperiod and CO۲ Concentration on Growth, Phytochemical Characteristics and Essential Oil Content of Thyme

Thymus vulgaris L., a member of the Lamiaceae family, is one of the most widely used medicinal and aromatic plants. This experiment aimed to investigate the effects of CO۲ enrichment at ۳۵۰, ۷۰۰, and ۱۰۰۰ mg/L (C۱, C۲, and C۳) combined with supplementary lighting photoperiods of ۱۲, ۱۶, and ۲۰ hours (L۱, L۲, and L۳) on several attributes of T. vulgaris. Measurements included fresh and dry weights of plant organs, photosynthetic pigments, essential oil quantity and composition, as well as the activity of catalase, ascorbate peroxidase, and polyphenol oxidase. The antioxidant capacity, along with the assessment of phenolic compounds and flavonoid content, was also conducted. The L۳C۳ treatment significantly improved several parameters, including fresh weight, dry weight, plant height, chlorophyll a, chlorophyll b, essential oil content, carotenoids, phenolic compounds, flavonoids, and antioxidant activity. These showed respective increases of ۱۱۰%, ۲۷۶%, ۸۲%, ۶۳%, ۶۳%, ۱۶۰%, ۴۵%, ۶۸%, ۱۳%, and ۴۵%. Additionally, the L۳C۱ treatment significantly enhanced peroxidase activity by a factor of ۱۰۸%. Furthermore, under the L۳C۱ treatment, catalase, superoxide dismutase, and polyphenol oxidase activities increased by ۳۷%, ۵۰%, and ۷۳%, respectively.

کلیدواژه ها:

CO۲ ، photoperiod ، Antioxidant activity ، Thymus vulgaris