4个桂花品种开花进程释放VOCs动态变化分析

Changes of volatile organic compounds released during flowering in four Osmanthus fragrans cultivar groups

为揭示自然条件下桂花Osmanthus fragrans开花进程中挥发性有机化合物(VOCs)释放动态变化,采用动态顶空气体循环采集法与热脱附-气相色谱-质谱(TDS-GC-MS)联用技术,选择金桂(Luteus group),银桂(Albus group),丹桂(Aurantiacus group)和四季桂(Asiaticus group)各1个品种进行开花进程所释放的VOCs成分收集测定。结果表明:4个桂花品种VOCs释放量依次为四季桂(1 704.56)>银桂(1 675.26)>金桂(1 383.48)>丹桂(1 062.76),均为单峰曲线,盛花期达到最大值;丹桂释放VOCs种类最多;4个桂花品种盛花期释放的VOCs主要是萜烯类,含量均大于63.0%,还有烃类、醛类、醇类、酮类、酯类及芳香族类化合物。其中金桂VOCs中主要成分为β-紫罗兰酮、萜品醇,银桂主要为β-紫罗兰酮、芳樟醇,丹桂主要为β-蒎烯、乙酸-3-己烯酯,四季桂主要为萜品醇、β-紫罗兰酮。

To reveal dynamic changes of the volatile organic compounds（VOCs） released in the flowering process of Osmanthus fragrans, the composition and content of flower VOCs in the four groups of cultivars（Lutens graup, Albus group, Aurantiacus group and Asiaticus group） were analyzed under near-natural conditions using the dynamic headspace air-circulation method and the thermal desorption system/gas chromatography/mass spectrometer（TDS-GC-MS） technique. Results of the four groups listed in descending order towards VOCs release were as follows： Asiaticus group（1 704.56）〉Albus group（1 675.26）Luteus group（1 383.48）〉Aurantiacus group（1 062.76）〉. The VOCs release of four groups had single-peak-curves. During the full bloom stage,the Aurantiacus group of cultivar released the most kinds of VOCs. More than 63% of the VOCs in the four groups was terpene, and the left contained hydrocarbons, aldehydes, alcohols, ketones, esters, and aromatic compounds. Major VOCs in each group of cultivar were as follows： mostly β-ionone and terpineol in Luteus group; mainly β-ionone and linalool in Albus group; mostly β-pinene and acetate-3-hexen-1-ol in Aurantiacus group; and mostly terpineol and β-ionone in Asiaticus groups.