Variations in chemical components of essential oils in 25 accessions of damask rose (Rosa damascena Mill.)

Damask Rose (Rosa damascena Mill.) is an important medicinal and industrial species. To achieve more and better-quality essential oil identifying the superior accessions of Damask Rose and their genetic relationships is very important. For a detailed review of the relationship among the genotypes of this species and variations in the essential oil composition, the use of multivariate statistical analysis could be useful. In this study, 25 different accessions of Damask Rose were collected from Kermanshah province and other regions of Iran and were planted in a randomized complete blocks design. The essential oil was extracted from the petals with hydrodistillation method. Essential oil composition was identified by using the gas chromatography and gas chromatography coupled with mass spectrometry and the amount (percentage) of each composition was measured. Essential oil compositions were evaluated using cluster analysis. According to the results of cluster analysis, the accessions were grouped in four groups. Discriminant analysis confirmed the results of cluster analysis. Component analysis showed that the accessions were in four groups and there were four different trends among the accessions studied for the chemical compositions of essential oils. According to the correlation analysis, the two important factors, geraniol and citronellol, which increased the quality of essential oil compounds in damask rose, showed a significant positive relationship with each other and with citronellyl acetate and geranial.