中国柴胡属植物叶表皮特征及系统学意义

Characters of Leaf Epidermis and Their Systematic Significance in Bupleurum from China

利用光学显微镜和扫描电镜对我国柴胡属(Bupleurum L.)13种(含1变种)植物的叶表皮进行了观察,首次报道了它们的微形态特征。结果表明:除了大叶柴胡(B.longiradiatum Turczaninow)气孔器仅存在于下表皮,其余12种柴胡的上、下表皮都存在气孔器,气孔器类型包括不规则型和不等型两种。叶表皮细胞形状为多边形或不规则型,垂周壁式样可区分为平直-弓形、浅波状。保卫细胞壁加厚明显,极端联合形成极层结构。在扫描电镜下,气孔器内陷于表皮细胞间。角质膜条纹状,有的条纹隆起,有的条纹上附有蜡质胶状分泌物和鳞片。光镜和电镜下叶表皮柴胡属微形态表现出相当高的多态性;而在特定的分类群中,又表现为高度的一致性,为种间分类提供了新的证据。

Leaf epidermis of 13 species in the genus Bupleurum L. was examined under both light microscope （LM） and scanning electron microscope （SEM）. Stomatas of most species occur in both abaxial and adaxial epidermis, and only B. longiradiatum Turczaninow has stomatas in abaxial epidermis. The shape of epidermal cells in Bupleurum examined are generally polygonal, and the anticlinal cell walls are either straight or curved. Only a few species are irregular, with the anticlinal cell walls sinuolate. Guard cells have thickened walls, forming polar lamellae at the polar end. Under the SEM, the cuticular membrane in the genus is usually striated. The wax ornamentations are flaked, striate to wrinkled or granular. These uniform micromorphological characteristics in the genus are important in classifications of studied species.