Rhabdosciadium aucheri has a limited distribution in west, center, and south of Iran. The aim of the present study was to assess essential oil content and variability in seven natural populations employing GC-FID and GC-MS analyses. Aerial parts of the specimens were collected at the full flowering stage. Overall, 27 chemical components were determined in the populations. The essential oil yields varied from 0.05% to 0.12%. The most abundant compounds were germacrene D (10.7-51.7%), β-sesquiphellandrene (0.8-54.6%), β-elemene (0.3-39.5%), juniper camphor (3.5-20.8%), limonene (0.4-19.6%) and α-pinene (0.4-4.5%) among the populations. Due to some variations observed in the essential oil components between populations, four different chemotypes were recognized including Chemotype I (germacrene D/β-sesquiphellandrene/juniper camphor), Chemotype II (β-elemene/germacrene D), Chemotype III (germacrene D/β-sesquiphellandrene) and Chemotype IV (β-elemene/germacrene D). The variations that occurred in chemical compositions among populations could be valuable in the pharmaceutical industries and conservation strategies.
Keywords: Apiaceae; Rhabdosciadium aucheri; chemical composition; chemotype; essential oil.