Chemical composition diversity in wild populations of Artemisia sieberi Besser under the same climate conditions

To identify the superior population of Artemisia sieberi in the Qom region of Iran, populations of this species were collected from that specific area. Populations were cultivated under the same environmental conditions in a domestication field for two growing seasons. Cultivation followed a randomized complete block design (RCBD) with three replications. Principal components analysis (PCA) showed that the first three principal components (PC1–PC3) accounted for approximately 91.93% of the total variation in the 32 extracted chemical compositions of the essential oils. Essential oils were obtained from cultivated A. sieberi populations under the same climate conditions at the domestication farm. The first component (PC1) explained the most significant fraction of the total variability in the original data, accounting for 76.15% of the total variations. It had a direct eigenvalue association with camphor (10.02–50.19%), camphene (1.20–12.24%), bornyl acetate (up to 6.54%), and borneol (up to 27.07%). Hierarchical cluster analysis (HCA) divided the 20 different populations into three main groups, with the ability to introduce three separate chemotypes and a high diversity distance. Generally, the Venan (VEN) population exhibited chemotype A with the highest content of essential oil (1.28%) and hydrocarbon sesquiterpenes (4.68%). The Qaleh-cham (QLC) population displayed chemotype B with the highest content of oxygenated monoterpenes (87.95%) and the lowest content of hydrocarbon monoterpenes (5.60%). The Mehr-zamin (MHZ) population, classified as chemotype C, had the highest content of oxygenated sesquiterpenes (8.02%). Particular emphasis is placed on the proportion of camphor content to the total essential oil content, which has emerged as a reliable method for distinguishing different chemotypes.