桃叶释放挥发性有机物成分及变化规律

Components and change laws of volatile organic compounds from peach leaves

【目的】探究在生长季桃叶片释放植物源挥发性有机物(BVOCs)成分组成和相对含量的动态变化特征。【方法】采用动态顶空采集法收集叶片释放的BVOCs,结合自动热脱附-气相色谱/质谱联用技术进行BVOCs成分的测定。【结果】在整个生长季(5—10月),桃叶共释放12类266种BVOCs,其中烷烃类(44)、烯烃类(41)和醇类(40)种类数量较多,组分总量从大到小的月份分别为:9月(115)、8月(84)、7月(79)、6月(73)、5月(72)、10月(27),以释放烷烃类、烯烃类、芳香烃类、酯类、醛类、酮类和醇类为主;除5月外,各月烯烃类BVOCs相对含量在一天中表现为上午>下午,其他类别BVOCs相对含量峰值会出现在任意时间点,当烯烃类BVOCs相对含量下降时,烷烃类、芳香烃类、酯类、醛类和醇类也会出现明显变化;桃叶共检测出8类45种有益BVOCs成分,主要包括烯烃类、酯类、醛类和醇类BVOCs,有益组分总相对含量为夏季(39.50%)>秋季(36.71%)>春季(35.99%);一天内各时间点有益成分的相对含量和数量随月份增加呈波动下降趋势,一般在10:00和14:00达到最高值,其中春季(5月)08:00释放有益BVOCs的相对含量为全年同时间点最高(77.85%),释放的主要有益BVOCs成分包括α-蒎烯、3-蒈烯、罗汉柏烯、乙酸乙酯、天然壬醛和庚醛。【结论】桃叶释放BVOCs组分存在明显的季节动态变化性和日变化差异,有益BVOCs成分丰富,且桃树林内最佳游憩时间段为08:00—10:00。

【Objective】To investigate the dynamic changes in the composition and relative content of plant-derived volatile organic compounds(BVOCs)released from peach leaves during the growing season.【Method】The BVOCs released from the leaves were collected by dynamic headspace acquisition method,and the BVOCs were determined by automatic thermal desorption-gas chromatography/mass spectrometry.【Result】During the whole growing season(May to October),a total of 266 BVOCs of 12 types were released from peach leaves,among which alkanes(44),olefins(41)and alcohols(40)were abundant,and the total components were September(115),August(84),July(79),June(73),May(72)and October(27),mainly alkanes,olefins,aromatic hydrocarbons,esters,aldehydes,ketones and alcohols.Except for May,the relative content of olefin BVOCs in the morning was higher than that in the afternoon each month,and the peak relative content of other types of BVOCs would occur at any time point,and when the relative content of olefin BVOCs decreased,alkanes,aromatic hydrocarbons,esters,aldehydes and alcohols would also change significantly.A total of 45 beneficial BVOCs in 8 categories were detected in peach leaves,including olefins,esters,aldehydes and alcohols,and the total relative content of beneficial components was>in summer(39.50%)>autumn(36.71%)spring(35.99%);The relative content and quantity of beneficial components at each time point in a day fluctuated and decreased with the increase of months,and generally reached the highest value at 10:00 and 14:00,among which the relative content of beneficial BVOCs released at 08:00 in spring(May)was the highest in the same time of the year(77.85%),and the main beneficial BVOCs released includedα-pinene,3-carenene,mohancyne,ethyl acetate,natural nonanal and heptanal.【Conclusion】There were obvious seasonal dynamic changes and diurnal variations in the release of BVOCs from peach leaves,and the beneficial BVOCs were abundant,and the best recreation time in peach forest was 08:00-10:00.