Evaluation of morphological variation of different populations of Rosa damascena Mill. from Kashan and its correlation with essential oil content

Fifteen populations of Damask rose were collected from important rose oil production regions of Kashan for evaluation of morphological variation. Fifty two quantitative and seventeen qualitative morphological characters were measured. Cluster and Principal component analysis (PCA) of morphological characters showed that the fifteen populations could be divided into two major groups including five subgroups. The variance analysis showed significant differences (P<0.01) among populations of Rosa damascena for 28 morphological characters such as stem length, leaf length and number of flowers per plant. Significant correlations were observed between different traits. The results are indicative of morphological variation among different populations of R. damascena from Kashan. Therefore, some of the traits such as number of flower per branch and number of flowers per plant, which showed a positive strong correlation in this study, or the number of prickle can be used as significant and important attributes in determining the criteria for the evaluation and selection of populations. The essential oil content (w/w) of flowers was assayed after extraction in Clevenger apparatus. Correlation results showed that there is a significant relationship between some morphological characters and essential oil content. Stipule length had a significant positive correlation with the essential oil content, while a significant negative correlation was observed for pedicle length and receptacle glandular length with the essential oil content.