4个桂花品种叶片挥发物成分及其对空气微生物的影响

 采用动态顶空气体循环吸附法和热脱附-气相色谱-质谱（TDS-GC-MS）联用技术，分析了近自然状态下金桂Osmanthus fragrans ‘Thunbergii’，银桂O. fragrans ‘Odoratus’，丹桂O. fragrans ‘Aurantiacus’和四季桂O. fragrans ‘Semperflorens’叶片挥发物（VOCs）的组分和含量；同时采用自然沉降法，调查了4个桂花品种林地空气中微生物（细菌、真菌和放线菌）的数量。结果表明：金桂叶片VOCs中主要成分为（Z）-乙酸-3-己烯酯、己醛、辛醛、壬醛、癸醛、6-甲基-5-庚烯-2-酮和3-己烯醇；四季桂主要成分为（Z）-乙酸-3-己烯酯、己醛、苯甲醛、壬醛、癸醛、6-甲基-5-庚烯-2-酮和壬烷；银桂和丹桂主要成分为（Z）-乙酸-3-己烯酯、己醛、辛醛、壬醛、癸醛、壬烯、6-甲基-5-庚烯-2-酮和3-己烯醇。金桂林地中细菌数量在3，5，7，9和11月比对照分别降低46.6%，48.3%，67.6%，34.6%和26.0%（P＜0.01），其他3个桂花品种林地中细菌数量在不同月份与对照相比均有不同程度的降低；金桂林在3，7和9月对真菌抑制作用极显著（P＜0.01），比对照分别降低33.5%，38.8%和34.1%；4个桂花品种林对放线菌也具有明显的抑制作用。上述结果说明：4个桂花品种树木可以降低林地空气中微生物的数量，对改善空气质量具有显著的作用。图3表1参18

Volatile organic compounds in leaves of Osmanthus fragrans and their effect on airborne microorganisms

To clarify the functions of plant volatile organic compounds （VOCs） on bacteriostasis and air decontamination，composition and content of VOCs in leaves of four cultivars of Osmanthus fragrans： ‘Thunbergii’，‘Odoratus’， ‘Aurantiacus’ and ‘Semperflorens’ were analyzed under near-natural conditions using the thermal-desorption cold trap gas chromatography/mass spectrometer technique. The airborne microorganism count （bacteria，fungi，and actinomycetes） for the four cultivars and a control of open ground were determined for March，May，July，September，and November in 2011 using natural sedimentation. Results showed that the major VOCs as follows：（Z）-acetate-3-hexen-1-ol，hexanal，octanal，nonanal，decanal，6-methyl-5-hepten-2-one，and 3-hexenol in ‘Thunbergii’；（Z）-acetate-3-hexen-1-ol，hexanal，benzaldehyde，nonanal，decanal，6-methyl-5-hepten-2-one，and nonane in ‘Semperflorens’；（Z）-acetate-3-hexen-1-ol，hexanal，octanal，nonanal，decanal，nonene，6-methyl-5-hepten-2-one，and 3-hexenol in ‘Odoratus’ and ‘Aurantiacus’. Compared to a control of open ground，the ‘Thunbergii’ stands for the five data collection months had significantly lower （P ＜ 0.01） bacterial counts；the ‘Thunbergii’ stands for March，July，and September had significantly lower（P ＜ 0.01） fungal counts；and all four cultivars for the five data collection months had significantly reduced （P ＜ 0.01） actinomycete counts. Thus，the four O. fragrans cultivars could reduce the quantity of airborne microorganisms thereby improving air quality.［Ch，3 fig. 1 tab. 18 ref.］