Analysis of the aroma composition of different flower organs of two peony varieties

'Qiao Ling' and 'Yang Fei Chuyu' are important parent hybridization materials for breeding fragrant peony. The aromatic profile of different flower organs can provide a theoretical foundation to isolate, identify, clone and express genes in a fragrant peony molecular breeding program. Test material included typical fragrant peony varieties 'Qiao Ling' and 'Yang Fei Chuyu', as well as the light-scented peony variety 'Fen Yu Nu'. Headspace solid-phase microextraction and gas chromatography-mass spectrometry (GC-MS) were used to analyze the aromatic profile of petals, petaloid stamens, pistils, and sepals. Results showed that 'Yang Fei Chuyu' contains 29 aroma components, mainly geraniol(27.62%), phenylethyl alcohol(18.00%), 3, 7-dimethyl-2-octene alcohol(14.56%), and α-pinene(9.79%). Aromatic compounds could not be detected in 'Fen Yu Nu' petals, thus the above listed components define 'Yang Fei Chuyu' fragrance. 'Qiao Ling' contains 41 aromatic compounds, mainly linalool(30.06%), eucalyptol(23.28%), benzyl ethanol(22.09%), leaf alcohol acetate(11.86%), and caryophyllene(5.24%). Linalool, benzyl ethanol, eucalyptol and caryophyllene are the main source of 'Qiao Ling' fragrance. The release amount of aroma components between the flower organs of 'Yang Fei Chuyu' and 'Qiao Ling' showed obvious differences, highest in petaloid stamens, followed by the outer petals, pistils and sepals. The aromatic profile of 'Yang Fei Chuyu' and 'Qiao Ling' are distinctly different among these flower organs.