避雨栽培对桃果实挥发性物质形成的影响

避雨栽培在园艺植物生产中得到了越来越多的应用，而有关该技术对果实挥发性物质形成的影响并不清楚。研究以中国水蜜桃品种‘玉露’为试材开展避雨栽培，以露地栽培作为对照，不同成熟阶段分别取样直至商业采收。实时数据监测显示覆膜的避雨栽培并不显著改变果园空气温度、相对湿度和土壤温度等微环境，但显著降低了土壤相对湿度并减弱了光照。采用顶空固相微萃取（HS–SPME）结合气相色谱质谱联用（GC–MS）方法在桃果实中鉴别出包括碳六化合物、醛类、醇类、酯类、内酯类、萜烯类、萜烯类衍生物和苯环化合物等11大类挥发性物质。利用偏最小二乘判别分析（PLS–DA）构建的模型可以明显区分避雨栽培和露地栽培的桃果实的挥发性物质，与电子鼻技术检测的结果相似。根据变量投影重要性指标（VIP）鉴别出了不同栽培模式下浓度具有显著差异的18种挥发性物质，整体趋势表现为避雨栽培果实产生了较高浓度的顺–3–己烯醇、反–2–己烯醇等“青香型”物质，而顺–3–乙酸己烯酯、γ–十一内酯和δ–癸内酯等“果香型”物质含量较低。

Effects of Rain-shelter Cultivation on Formation of Peach Fruit Volatile Compounds

Although rain-shelter cultivation is getting more attentions in horticulture crops production，its effect on formation of volatile compounds remains unclear. In present study，fruits of cultivar‘Yulu’（Prunus persica L. Batsch‘Yulu’）were grown under rain-shelter and open field as the control，and the fruit were harvested at different maturity stages. Real-time data indicated that rain-shelter treatment significantly reduced soil relative humidity and light transmission，but no significant changes were found for air temperature，relative humidity and soil temperature eleven classes of volatiles wereidentified in peach fruit by solid phase microextraction coupled to gas chromatography mass spectrometry techniques，including C6 compounds，aldehydes，alcohols，esters，lactones，terpenes，terpenoids，phenylpropanoids and others. Peach fruit treated with rain-shelter cultivation could be clearly distinguished from the controls by partial least squares discriminant analysis（PLS–DA），being consist with results produced by electronic nose analysis. Eighteen volatile compounds that contributing to differences in volatile compositions between rain-shelter cultivation and open field fruit were identified based on variable importance in projection（VIP）value. Peach fruit treated with rain-shelter produced higher contents of “green note”C6 alcohols such as（Z）-3-hexenol and（E）-2-hexenol，and lower concentrations of“fruity note”γ-Undecanolactone，γ-Decalactone and（Z）-3-Hexenyl acetate.