国产赖草属的叶表皮特征与组群划分

Leaf epidermal characteristics and classification of sections of Leymus from China

对国产赖草属15个种的叶片表皮进行了光镜观察,发现下表皮呈现的微形态差异可以把国产类群划分为3个群体,并参照各群体所具的外部形态特征,3个群体应分别属于前人组群划分中的3个组,即多穗组(sect.Leymus)、少穗组(sect.Aphanoneuron(Nevski)Tzvelev)和单穗组(sect.Anisopyrum(Griseb.)Tzvelev)。同时,根据叶表皮性状的递变趋势,分析了3个国产组的亲缘关系。结果表明:多穗组最原始,单穗组最高级,少穗组演化居中;单穗组与少穗组亲缘关系直接,与多穗组关系间接。

The leaf epidermises of 15 species of Leymus were examined under the light microscope. It was found that these mieromorphological differences shown by the lower epidermis may be applied to dividing the Chinese Leymus species into three groups. And in accordance with the external characteristics of each group, these three groups should separately belong to sect. Leymus, sect. Aphanoneuron and sect. Anisopyrum which were described by our predecessors. Moreover, according to the variation trends of leaf epidermal characters, the relationships among three Chinese sections were analysed as well. The results show that sect. Leymus is the most primitive and sect. Anisopyrum is the most advanced among three sections, whereas sect. Aphanoneuron lies between the above two sections; sect. Anisopyrum shows direct relationship with sect. Aphanoneuron, but indirect relationship with sect. Leymus.