Essential oil composition of Rhabdosciadium aucheri from Iran

Chemical compositions of the essential oils from Iranian populations of Rhabdosciadium aucheri Boiss. (Apiaceae)

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.

RAPD-based evaluation of genetic diversity among populations of the Iranian endemic species Rhabdosciadium aucheri Boiss. (Apiaceae)

Rhabosciadium aucheri is an Iranian endemic herbaceous species that grows in the west, center, and south regions of Iran. In the present study, genetic variation of 70 individuals belonging to seven natural populations of four provinces was investigated using Random Amplified Polymorphic DNA (RAPD) markers. Ten out of twenty-two RAPD primers employed in this study, generated 110 highly amplified and reproducible loci and a mean of 11.1 bands per primer and 48.13% of polymorphism was obtained. According to our results, the primer OPA10 presented the highest effective number of alleles, Shannon's index, and genetic diversity. The highest value of genetic identity (0.916) was determined between Hamadan, Nahavand and Hamadan, Alvand Mts. populations and the highest genetic distance (0.277) was observed between Hamadan, Asadabad and Kurdistan, Qorveh populations. Therefore, there is an obvious correlation between genetic diversity and geographical distribution. PCA was obtained based on RAPD molecular data and Neighbor Joining (NJ) dendrogram was provided successively. Similar results were attained employing UPGMA and Neighbor Joining dendrograms, supported by PCA ordination plot. Overall, almost moderate level of polymorphism was obtained by RAPD molecular markers at the population level that shows a reasonable amount of intraspecific variability. The reason might be due to the low level of gene flow between populations that could give rise to high genetic differentiation.