中文摘要：

采用气相色谱技术测定了蓼科（Polygonaceae）4属7种植物叶表皮蜡质正烷烃的含量和相对含量,并通过扫描电镜（SEM）观察了叶表皮的蜡质晶体形态,旨在为植物化学分类提供新的途径,同时也为合理开发利用蓼科植物资源提供科学依据.结果表明：蓼科植物叶表皮蜡质中正烷烃的含量和相对含量均存在种间差异,且奇数烷烃的相对含量明显高于偶数烷烃,其中C29和C31的相对含量最高,其次是C33,碳链＜C27和＞C33的烷烃的相对含量较低.长链烷烃的碳优势指数（CPIs）在1.1～7.1之间,短链烷烃CPIs在0.6～3.1之间.植物叶表均覆盖一层蜡质薄膜,弥漫性分布于叶表.蜡质薄膜之上散布蜡质晶体,其中丛枝蓼（Polygonum posumbu）、头花蓼（P.capitatum）、巴天酸模（Rumex patientia）和火炭母（P.chinense）的蜡质晶体主要呈颗粒状,何首乌（Fallopia multiflorum）呈杆状,水蓼（P.hydropiper）和金荞麦（Fagopyrum dibotrys）呈片状.蓼科4属7种植物经聚类后可分为2大类：I类仅包括以C19和C21为主要烷烃的丛枝蓼,Ⅱ类包括以C29,C31或C33为主要烷烃的其他6种植物.

英文摘要：

The amounts and relative contents of n-alkanes in epicutiuclar wax of seven species of Polygo naceae were analyzed using GC technology, and the crystal morphology of epicuticular wax was observed by SEM. The experiment aims to provide a new path for plant chemical classification and scientific theory for utilizing and developing Polygonaceae. Results showed that the amounts and relative contents of n al- kanes in the epicuticular waxes were different among species. The relative content of odd-numbered n-al- kanes was significantly higher than that of even numbered n-alkanes. The most abundant n alkanes were C29 , C31 and C33, and the relative contents of n alkanes 〈C27 and 〉C33 were relatively lower. The carbon preference index （CPIs） of long chain n-alkanes ranged from 1.1 to 7.1, while the CPls of short chain n-al kanes ranged from 0.6 to 3.1. SEM analysis showed that a dense, diffused wax film was covered on leaf surface of tested plants and crystals were spread over the film. The predominant wax crystal type of Po lygonum posumbu, P. capitatum, Ruznex patientia and P. chinense was granular, that of Fallopia multi- florum was long rod, and that of P. hydropiper and Fagopyrum dibotrys was flat. Seven species of four genera in Polygonaceae could he clustered into two groups. One was P. posumbu mainly containing C19gand C21, the others included plants mainly containing C29, C31 or Ca3.