The essential oil yield stability of damask rose (Rosa damascena Mill.) as an important medicinal and aromatic plant in different environments has not been well documented. In order to determine appropriate stability parameters, six statistics were studied for essential oil stability of 35 Rosa damascena landraces in seven locations (Sanandaj, Arak, Kashan, Dezful, Stahban, Kerman, and Mashhad) and two years (2007-2008) in Iran, using a randomized complete blocks design with three replications. Significant differences (P<0.01) were observed in essential oil ratio among landraces (G), locations (L), and environments (E) and in landrace × location (GL) and landrace × environment (GE) interactions. The positive correlation of environmental variance (S2), coefficient of variation (CV), and regression coefficient of yield over environments (b) with essential oil suggest that only low-yield landraces develop a similar phenotype over a range of environments and show static stability. Although there were not any stable landraces by b (b ≈ 0) and all of the stable ones by S2 produced very low yields, some of the adaptable ones by CV (e.g. KM1) showed high essential oil ratios and stability simultaneously. The stable landraces according to the dynamic stability concept (b ≈ 1, Sd2 or variance due to deviation from regression ≈ 0) produced moderate essential oil. Superiority index (P) determined some of the highest essential oil as adaptable landraces. The stable landraces with the least variance of the years within places (MSY/P) produced the least essential oil. It could be concluded that a genotype can demonstrates both static and dynamic stability with high essential oil content. In addition, CV, dynamic view statistics (b ≈ 1, Sd2≈ 0), and P are proposed as desirable parameters for the evaluation of essential oil stability with different concepts in damask rose genotypes. تفاصيل المقالة

This study was conducted to assessthegenetic variety of 12 damask rosegenotypes of Kurdistan using morphological traits in Zaleh Research Farm affiliated to Kurdistan Province Agriculture Research Center. The experiment was carried out as a randomized complete block design with three replications and each replication included three stocks in each genotype. Results of analysis of variance showed significant differences among the studied genotypes at the probability level of 1%. Results of mean comparison showed a wide variety for studied traits in different genotypes. Relationship between traits showed that the number of flowers, plant height, average width, average length, average number of leaves, mean flower diameter, and petal to flower weight ratio per stem had positive and significant correlation at 1% probability level. Based on cluster analysis, 12 genotypes of damask rose were divided into four distinct groups according to different traits. Thus, according the results, genotypes Kurdistan 3 and Kurdistan 2 can be introduced as superior genotypes. Kurdistan 3 had high yield in flower per hectare and the number of flowers in per bush, and Kurdistan 2 had the highest flower diameter. تفاصيل المقالة