Analysis of flower volatile compounds and odor classification of 17 tree peony cultivars

•65 tree peony cultivars were evaluated and classified by sensory evaluation.•The volatile compounds of 17 tree peony cultivars were determined and analyzed.•Odor activity values were used to analyze the contribution of compounds to fragrance.•The odor types of 17 tree peony cultivars were classified. As one of the significant ornamental characteristics of tree peony, floral fragrance has garnered considerable attention. In this study, 65 cultivars of tree peony were classified into three groups based on their sensory evaluation scores: strong fragrance, medium fragrance, and no/light fragrance and 9 strong fragrance cultivars, 6 medium fragrance cultivars, and 2 light/no fragrance cultivars were selected for substance analysis. Using gas chromatography-mass spectrometry (GC–MS), 77 volatile organic compounds (VOCs) were identified and classified from 17 tree peony cultivars, they were terpenoids, benzenoids/phenylpropanoids, and fatty acid derivatives. Monoterpenoids were the main volatile compounds in the cultivars ‘Souvenir de Maxime Cornu’, ‘Okan’, ‘Chromatella’, ‘Yapianzi’, and ‘Liuli Guanzhu’, while benzenoids/phenylpropanoids were the main volatile compounds in ‘Shaonvqun’ and ‘Binglingzi’. Through the calculation of odor activity value (OAV), 17 cultivars were categorized into four distinct groups: flower-sweet scent, flower-rose scent, herb scent and mixed scent. This investigation presented the composition and classification of fragrant compounds of 17 tree peony cultivars and classified the odor profiles based on the contribution of flower volatiles to the overall olfactory experience, offering valuable materials for genetic enhancement of tree peony floral fragrance. [Display omitted]