Dynamic distribution of volatile organic compounds emitted by lilac at various developmental stages

Lilac flowers emit diverse volatile organic compounds (VOCs) that contribute to their characteristic fragrance. However, limited research has been conducted on the characteristics of VOCs emitted by naturally grown lilac flowers from the bud to withering stages. To investigate the variations in the VOCs of lilacs across different developmental stages, dynamic headspace sampling combined with gas chromatography-mass spectrometry (GC-MS) detection was adopted to collect and identify VOCs emitted by Syringa oblata , Syringa meyeri and Syringa vulgaris at various developmental stages, and statistical methods were applied to screen key differential compounds. A total of 73 VOCs belonging to 7 categories were emitted by the three lilac species across all developmental stages, and the VOCs content differed significantly among developmental stages. For Syringa oblata , 2-butenal and octanal peaked at the full flowering stage. While 2-ethyl-2-hexenal and (Z)-3,7-dimethyl-1,3,6-octatriene were the most abundant substances in Syringa meyeri at the flowering stage, most VOCs in Syringa vulgaris exhibited a U-shaped trend, which is opposite to the development of the other two lilacs. Terpenoids, including camphene, Limonene, and β-pinene, were observed to change considerably during flower development. These results revealed the dynamic distribution of VOCs in lilacs at different developmental stages.