Objective  Aromatics in various floral organs of Michelia platypetala Hongyun were analyzed for selective breeding and extended utilization of the fragrant components.

  Method   Headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were employed to determine the aromatic components in the tepals, stamens, and pistils of Michelia platypetala Hongyun at flower budding, early blooming, and full blooming stages. And conduct Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS-DA).

  Result  One hundred volatiles of 11 types were identified. Terpenoids and alkanes were the major ones that constituted over 80% of all. The contents of ketones, aldehydes, alcohols, heterocyclic compounds, and olefins were relatively low. Identify 100 types of floral aroma components, screen and list 49 substances based on the main aroma components (relative content>1%) and unique aroma components of each floral organ at different stages. The subsequently conducted PCA and PLS-DA analyses placed the aromatics in 13 distinct components at VIP＞1, indicating significant differences in the aromatic components of the three flower organs. The main aroma components of Michelia platypetala Hongyun perianth slices γ-cadinene and 1,2-Dimethoxybenzene have vanilla and sweet cream flavors, respectively, presenting a woody and herbaceous aroma. During the bud stage, the unique components of the petals, such as esters such as 2-Phenethyl hexanoate ester and ethers such as 2-Isopropyl-5-methylanisole, add a sweet and burnt wood flavor to the petals, presenting a floral and herbaceous aroma. The ketone substance D-carvone, a unique component of the early blooming petals, adds a stimulating flavor to the perianth slices, presenting a mint aroma. The main aroma components of stamens γ-Junipene and δ-Elemene has a vanilla and sweet flavor, respectively, presenting a woody and herbaceous aroma. The unique components of aldehydes and ketones at each flowering stage of stamens, such as Benzaldehyde and 3-Thujanone, add almond flavor and stimulating flavor to the stamens, presenting a fruity and woody aroma. Main aroma components of pistil γ-Junipene, (+)-Aromandendrene, and δ- Elemene has a vanilla, woody, and sweet flavor, respectively, presenting a woody and herbaceous aroma. Bud stage pistils specific components of alcohols γ-Terpineol alcohol for pistils added pine flavor and clove flavor, presenting a woody aroma.

  Conclusion  The aroma components of the organs of Michelia platypetala Hongyun are rich. The main aroma components are terpenoids and alkanes, and the main aroma releasing site is the stamen during the bud stage. During the flowering process, the aroma characteristics are constantly changing due to the relative content and types of various aroma components, making each flower organ present unique and diverse floral fragrance in three flowering periods.