Evaluation of Chemical Compounds of Essential Oil in Damask Rose (Rosa damascena Mill.) Accessions

Damask Rose (Rosa damascena Mill.) is a valuable species whose various products are widely used in food, pharmaceutical, cosmetic and traditional medicine. This plant is cultivated in different countries such as Turkey, Italy, Bulgaria, Spain, India, and Iran. In this research, fifteen different genotypes were cultivated in a randomized complete block design with 3 replications. Within 2 years, Essential Oil (EO) was extracted by water distillation method and the chemical compounds were identified and determined by GC and GC/MS. Twenty chemical compounds were identified in essential oil, which has formed about 97.81% of the EO. The results showed that geraniol (21.89%), n-nonadecane (19.59%), n-henicosane (16.45%), geranial (13.30%), and n-tricosane (6.87%) had the highest share in the chemical compounds. A significant difference was observed for the compounds of Trans- rose oxide, n-undecanol, 2-6-E-farnesol, n-pentane at the level of 5% and for 1-hexyl hexanoate, γ- elements, α-cadinene, Butyl decanoate, n-hexadecanoic, and occidental acetate at 1%. There was a significant difference between the genotypes for all chemical compounds of essential oils. Also, the year/genotype interaction was significant for all EO compounds, except geraniol, n-hexadecanoate and n-henicosane. Genotypes were classified into 4 groups by cluster analysis (Ward’s method) and Discriminant Function Analysis confirmed the results of cluster analysis. The results of the principal component analysis showed that the compounds n-heptane, n-pentane, n-hexadecanoic, and butyl decanoate had the most positive contribution and the compounds linalyl acetate, geranial, hexyl hexanoate and trans- rose oxide had the most negative share in the first component. KEYWORDS: Essential oil, Gas chromatography, Gas chromatography with mass spectrometer, multivariate analysis.