Abstract: The leaf epidermal morphology and structure of 15 germplasms belong to 12 Elytrigia Desv.species at heading stage were examined using scanning electron microscope at the beginning of June,2008 in order to provide scientific basis for the taxonomy of the genus.The results show that the long cells and stomata cells were found in the upper epidermis of all species.The tested germplasms except for EE009,EE022,EI021,EI029,EPY002,EC002,EH001,and ES001 showed papillae in spot,spherical,or oblique shapes.The prickle hair existed in the tested germplasms except for EC002,EE009,EE022,EJ001,EPO004,and EPY002.The short cells showed horseshoe or oval shapes and only existed in EB001,EC002,and EL001.The macrohair was only found in EJ001 and ES001.According to the leaf transverse sections,the bulliform cells were found in the intercostal zone of all tested germplasms and showed sank and formed into the hinge cells only in EB001,EH001,and EPY002.Two layers of the vascular bundle sheaths were showed in all germplasms,and the fibre was distributed in both upper and below sides of the vascular bundle and joined together.At the same time,the 15 germplasms were divided into 6 groups indicating the genetic relationships among them according to the Euclidean Distance Cluster Analysis based on 10 indices of the leaf epidermal morphology and structure.

Key words: Elytrigia Desv., Leaf epidermal morphology, Anatomy structure, Cluster analysis

摘要： 于2008年6月初对偃麦草属12个植物种15份种质材料抽穗期的叶片表皮形态与结构进行了扫描电镜观察,旨在通过形态解剖结构特点的分析,为该属植物的分类鉴定提供科学依据。结果表明:所有材料上表皮都具有长细胞和气孔器细胞;除EE009、EE022、EI021、EI029、EPY002、EC002、EH001、ES001外,都含有乳突,呈斑泡状、圆头状或倾斜状;刺毛存在于除EC002、EE009、EE022、EJ001、EPO004、EPY002外的其他所有种;短细胞马蹄形或椭圆形,仅存在于EB001、EC002和EL001中;大毛仅在EJ001和ES001中发现;从横切面看,脉间普遍存在泡状细胞,且EB001、EH001、EPY002泡状细胞下陷形成"绞合细胞",其余均不下陷;维管束鞘2层,纤维分布在维管束的上下方,与维管束连接。然后,利用15份种质材料的10个叶片表皮的形态指标进行欧氏距离聚类分析,将其分为6类,较好地反映出各种质材料亲缘关系的远近。

关键词: 偃麦草属, 叶表皮形态, 解剖结构, 聚类分析