Flower yield and essential oil composition of oil-bearing rose genotypes under coastal ecological conditions

Oil-bearing roses are economically important for the perfumery and cosmetic industries; however, their performance under coastal conditions remains insufficiently characterized. This study evaluated flower yield, essential oil content, and volatile composition of four genotypes (Rosa damascena, R. alba, R. alba ‘Semiplena’, and R. centifolia) grown over two consecutive years under coastal conditions in Yalova, Türkiye. Essential oils were obtained by Clevenger hydrodistillation and analyzed by GC – MS. Significant genotypic differences were observed. Essential oil content ranged from 0.011% to 0.052%, with the highest values in R. alba and R. damascena and the lowest in R. alba ‘Semiplena’. Volatile profiles revealed clear genotypic differentiation: R. alba and R. damascena were enriched in monoterpene alcohols, whereas R. centifolia and R. alba ‘Semiplena’ showed higher levels of phenylethyl alcohol and long-chain hydrocarbons. Multivariate analyses confirmed genotype as the primary determinant, with year and harvest period as secondary factors. Coastal conditions supported satisfactory yield and oil quality.