Quali-quantitative variation of essential oil from Iranian rosemary (Rosmarinus officinalis L.) accessions according to environmental factors

The aim of this study was to assess the effects of environmental factors on quality and quantity of essential oil in Iranian rosemary. Chemical components were identified by GC-FID and GC-MS analyses. Results showed that essential oil yields exhibited significant variation among accessions. The highest contents were recorded for the Bo2 and Bo3 accessions (2.6 and 2.3 ml/100 g, respectively). In these areas the soil samples were richer in nitrogen. The major essential oil constituents were 1,8-cineole (5.32 to 28.29%), camphor (1.58 to 25.32%) and α-pinene (14.19 to 21.43%). The Iranian accessions also exhibited chemical variability for other major compounds such as borneol, piperitone, camphene, bornyl acetate, verbenone and trans-pinocamphone. Multivariate analyses including CA, HCA, DCA and PCA were also used to analyze the collected data. According to multivariate analysis, the Iranian rosemary accessions belonged to two main chemotypes (I camphor type, including Bo1–3, Ke1–3 populations, and II α-pinene/1,8- cineole/camphor type, including Bi1–3, Do1–3, Jo1–3, Kh1–3 and Ma1–3 populations). Results of CA and DCA were similar and both of them were in agreement with the results of PCA. Furthermore, there were positive and negative correlations between the major rosemary constituents and environmental factors in collection localities.