Abstract:

In order to investigate the spatiotemporal variations of volatile components in the flowers of Michelia platypetala ‘Fenyun’,this study used the tepals,stamens,and pistils at the bud stage,initial flowering stage,and full flowering stage as experimental materials.The volatile components were determined by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS).The results showed that a total of 93 volatile components,belonging to 11 major groups,were identified in the flowers of M. platypetala ‘Fenyun’,with sesquiterpenes being the most abundant.Furthermore,the highest release of total volatile components was observed in the tepals at the bud stage. A total of 73,86,and 86 volatile components were identified in the tepals,stamens,and pistils,respectively.Among them,there were 8,10,and 11 major volatile components with relative abundances greater than 2%.The main volatile components included 2,6,10-trimethyltetradecane,Isohecadecane,γ-cadinene,and β-isocomene.The specific components identified in the tepals were myrtenyl acetate,while the specific components in the stamens were umbellulone,prostantherol,derivative of and (E)-2-Octenal.In the pistils,the specific components included (E,Z)-2,6-Dimethylocta-2,4,6-triene,dodecane,farnesol formate,1-hexanol and 3,4-Dihydro-2H-pyran.In this study,further principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were performed on the identified volatile components using SIMCA 14.1.It was found that the volatile components released from different floral organs of M. platypetala ‘Fenyun’ could be well distinguished.Among them,12 components showed significant differences in their release quantities among floral organs (VIP > 1).In summary,the volatile components of M. platypetala ‘Fenyun’ were found to be most abundant in the tepals at the bud stage.Among the identified compounds,2,6,10-trimethyltetradecane, isohecadecane, γ-cadinene,and β-isocomene were identified as the major volatile components during the flowering process of M. platypetala ‘Fenyun’.

Key words: Michelia platypetala ‘Fenyun’, HS-SPME-GC-MS, flower organs, volatile components, PCA, PLS-DA