作 者 ：田建平1,2,胡远艳3,杨卫丽1,戴水平1,陈国良4*
期 刊 ：西北植物学报 2013年 6期 页码：1151~1158
Keywords:Apocynaceae, leaf epidermis, systematic significance, SEM,
摘 要 ：以萝藦科植物匙羹藤为对照,在扫描电镜下观察了传统上分属于夹竹桃科3亚科植物的叶下表皮特征。 结果表明:（1）所观察的夹竹桃科25种植物叶下表皮特征具有一定程度的多样性,如少数物种具有表皮毛;部分角质层表面有丝状蜡质;叶下表皮纹饰有条纹状、脊状皱褶增厚、块状突起、花蕊形和较平滑等类型;气孔大小差异较大,气孔外拱盖和内缘形状分浅波状和较平滑2种类型,气孔保卫细胞极区有T型加厚和无T型加厚两种类型,气孔外拱盖与表皮细胞间分凹陷和连续两种类型等,这些叶表皮特征对夹竹桃科植物属内和属间类型的分类以及对疑难类群的划分具有重要的参考价值。（2）夹竹桃科25种植物的绝大部分种的叶表皮气孔类型、气孔外拱盖及其内缘形态基本一致,但叶表皮纹饰、气孔外缘角质层特征呈现出较高的多样性,在属内各种和属间有较大的差异。（3）萝藦科植物匙羹藤与夹竹桃科植物盆架树在气孔形状,叶片气孔外缘角质层特征、气孔外拱盖等叶表皮特征具有高度的相似性,推测这两种植物的亲缘关系可能较近,而且萝藦科与夹竹桃科中一些植物的系统位置需进一步的研究。（4）本研究结果支持仔榄树属应从山橙族中分离出来独立成族,海杧果属应从萝芙木族中独立出来的观点;但不支持新的分类方法中将糖胶树和盆架树同归属于鸡骨常山属的观点。
Abstract:With Gymnema sylvestre (Retz.) Schult.as a control,we researched the characteristics of leaf lower epidermis for species which traditionally belonging to three subfamilies of Apocynaceae under SEM.（1）The characteristics of leaf lower epidermis were diverse in some degree for 25 species of Apocynaceae.Trichomes occurred in some species.Filamentous waxy occurred in cuticula surface of some species;Stomata size were different too;The shape of the outer and the inner stomata ledge have been divided into comparatively smooth and sinuolate types;The shapes of polar regions of stomatal guard cells have two types with T- thicker and non-T-thickening types;The joint cells between the outer stomatal ledge and epidermis could be divided into depression and continuous types.These characteristics of the leaf epidermis have important reference value for the classification of intergeneric and interspecific even difficult taxa in Apocynaceae.（2）They were similar in leaf epidermis stomatal types,the shape of the outer and the inner stomata ledge for most 25 species of Apocynaceae,but it existed higher diversity in decoration of lower epidermis and outer stomatal cuticle which have much difference in intergeneric and interspecific species.（3） The highly degree of similarity in the shapes of stomata,stomatal outer cuticle characteristics and the outer stomata ledge between G.sylvestre and W.calophylla was observed,and it could be deduced that they may have close relationship between the two species.The position of plant systematics for some species of Asclepiadaceae and Apocynaceae should be implemented further research.（4）The results of this research supported the viewpoints that genus of Hunteria should be separated from Trib.Melodineae as a single Trib.,and genus of Cerbera separated from Trib.Rauvolfieae.But it could not supported the viewpoint that Alstonia scholaris and Winchia calophylla were belonged to genus of Alstonia in new classification method.