中国木蓼属植物叶表皮微形态特征及其分类学意义

摘要

利用扫描电子显微镜(SEM)对国产蓼科(Polygonaceae)木蓼属(Atraphaxis Linn.)11个种类的叶表皮微形态特征进行了观察和比较、探讨其分类学意义,并据此编制了供试11个种类的分类检索表.观察结果表明:供试的11个木蓼属种类的叶表皮微形态特征(包括表皮细胞形状、垂周壁式样、叶表皮表面纹饰、角质膜、气孔器类型、气孔外拱盖内缘类型及其纹饰)均表现出较高的多样性.叶表皮细胞形状分为不规则形和多边形2类,垂周壁式样分为弓形和平直2类,多数种类具有不规则的表皮细胞以及弓形垂周壁；叶表皮表面纹饰分为乳头状突起、薄壁区、具条纹和加厚区4类,大多数种类叶片上、下表皮均无乳头状突起；气孔器包括无规则型、不等型和平列型3类,以不等型为主；角质膜可分为具条纹和条状隆起2类且部分种类具颗粒,以具条纹类型居多；气孔外拱盖内缘可分为浅波状和近平滑2类,气孔外拱盖纹饰则可分为具颗粒、近平滑和具条纹3类,供试11个种类以气孔外拱盖内缘浅波状且纹饰具颗粒为主.分析结果显示:木蓼属不同种类的叶表皮微形态特征多样性较为丰富,这些特征可作为区分该属部分种类的参考依据.%Leaf epidermal micro-morphological characteristics of eleven species of Atraphaxis Linn.(Polygonaceae) in China were observed and compared by scanning electron microscope (SEM),and its taxonomical significance was discussed.Hereby,key to eleven species tested was also compiled.The observation results show that micro-morphological characteristics (including shape of epidermal cells,pattern of anticlinal wall,surface ornamentation of leaf epidermis,cuticular membrane,type of stomatal apparatus,inner margin type and ornamentation of outer stomatal ledge) of leaf epidermis of eleven species tested appear high diversity.Shape of epidermal cell contains two types of irregular and polygonal,pattern of anticlinal wall contains two types of arched and straight,most species tested possess irregular epidermal cell and arched anticlinal wall.Surface ornamentation of leaf epidermis can be divided into four types of papillae,thin area,striate and thickened area,upper and lower epidermis of most species tested have no papillae.Stomatal apparatus can be divided into three types of anomocytic,anisocytic and paracytic with a majority of anisocytic type.Cuticular membrane contains two types of striate and apophysis,in which some species possess granules and striate is major.Inner margin of outer stomatal ledge can be divided into two types of sinuolate and nearly smooth,ornamentation of outer stomatal ledge also contains three types of granules,nearly smooth and striate,and sinuolate inner margin and granules ornamentation of outer stomatal ledge are main among eleven species tested.The analysis result indicates that diversity of mirco-morphological characteristics of leaf epidermis among different species of Atraphaxis Linn.is relatively rich,as a result,these characteristics are taken as references for distinguishing some species of the genus.