Comparative Physiological and Phytochemical Analysis of Two Artemisia Species (A. annua and A. sieberi) at Different Growth Stages in Tuskestan and Kalaleh Habitats, Golestan Province

Artemisia L. species are widely recognized for their medicinal and aromatic properties, making the study of their phytochemical composition crucial for maximizing their potential applications. This two-year study (۲۰۲۱-۲۰۲۳) investigated the impacts of growth habitat and developmental stage on the phytochemical profiles of two Artemisia species (Artemisia Annua L. and Artemisia Sieberi Besser). Plant materials were collected at three growth stages (vegetative, flowering, and seed formation stages) from two distinct habitats (Tuskestan and Kalaleh). Photosynthetic pigments, proline, total phenolics, flavonoids, anthocyanins, and essential oils were quantified using the established spectrophotometric and hydrodistillation methods. Variance analysis revealed significant effects of species, habitat, and growth stage on phytochemical content. A. annua generally exhibited higher photosynthetic pigment levels, reaching means of ۲۰.۶۷, ۸.۴۹, ۲۹.۱۵, and ۴.۷۳ μg/g FW for chlorophyll a, b, total chlorophyll, and carotenoids, respectively, during flowering in Tuskestan, while A. sieberi accumulated more proline, peaking at ۱.۷۵ µmol/g FW in Kalaleh. Anthocyanin content was also elevated in A. sieberi, reaching ۳.۳ mg CG/g FW during seed formation in Kalaleh. Total phenolic content reached ۱۹.۱۲ mg GA/g FW in A. sieberi during seed formation in Kalaleh, while flavonoid content peaked at ۹.۵۹ mg QA/g FW in A. annua during seed formation in Tuskestan. The essential oil content was significantly influenced by all factors, with A. annua demonstrating higher yields, reaching ۲.۳۴% during flowering in Kalaleh. Regression analysis identified significant relationships between the essential oil content and specific plant traits (total chlorophyll and total phenolics), soil properties (organic carbon), and climatic factors (altitude and average precipitation). GC-MS analysis of essential oil profiles revealed distinct compositional differences between the two species. The essential oils of A. annua and A. sieberi from the Tuskestan and Kalaleh habitats are characterized by Artemisia ketone as the dominant compound (۵.۳۲%–۵۸.۹۸%), with notable variations in other key compounds such as Borneol (۱۶.۲۸%-۵۰.۲۶%), α-fenchene (۰.۱۴%-۱۰.۷۵%), methyl chavicol, and linalool, showing distinct concentration patterns across growth stages. These results highlight the significant impact of ecological factors on the phytochemical composition of Artemisia species and suggesting potential implications for their targeted cultivation and utilization.

Keywords:

Artemisia , Phytochemical composition , Growth habitat , developmental stage , essential oil