八角目(Illiciales)植物花被片表皮比较形态

Comparative Morphology of the Tepal Epidermis in Illiciales

在光学显微镜和扫描电镜下,观察了八角科(Illiciaceae)八角属(Illicium Linn.)2组11种20个材料、五味子科(Schisandraceae)南五味子属(Kadsura Ksempf.ex Juss.)2亚属2组8种15个材料和五味子属(SchisandraMichx.)2亚属4组6种17个材料的花被片表皮形态特征。首次报道了八角目2个科(八角科和五味子科)3个属(八角属、南五味子属和五味子属)植物花被片表皮细胞的形状、分泌细胞的形状及分布、气孔器的形状及分布、花被片表面的纹饰。通过与八角目2个科3个属植物的叶表皮形态比较,发现花被片表皮气孔器外拱盖均为单层,与叶表皮气孔器外拱盖层数(常绿种类为双层和落叶种类为单层)之间没有相关性,还在五味子科中发现2个新的性状(气孔对和环列型气孔)。通过对两性花、雌花和雄花花被片表皮观察,发现花被片表皮形态与花的性别之间没有相关性。通过对八角属、南五味子属和五味子属花被片表皮比较,发现五味子属与南五味子属相比,其花被片表皮表现出更多的衍生性状;南五味子属与八角属相比,前者花被片表皮具有更多的衍生性状;而南五味子属花被片表皮形态与五味子属的相似性程度较大,支持五味子科包含南五味子属和五味子属、八角科包含八角属的观点。

The tepal epidermis of 20 samples, representing 11 species within IUicium Linn. （Illiciaceae）, 15 samples of 8 species belonging to Kadsura Kaempf. ex Juss. （Schisandraceae） ,and 17 samples of 6 species in Schisandra Michaux. （Schisandraceae）, were investigated using light microscopy and scanning electron microscopy. Several characters of tepal epidermis of the three genera in Illiciales, such as patterns of epidermal cells, shapes and distributing of secretory cells, types and distributing of stomatal apparatus, and cuticular ornamentations, were reported for the first time. Two new characters, stomata cluster and cyclotytic stomata, are introduced. The previous studies reported the correlations between the character of outer stomatal rims on leaf epidermis and the habit in Illiciales： single outer stomatal rims occured in deciduous species and double ones only in evergreen species. In this study, all the outer stomatal rims on tepal epidermis in Illiciales are single, different from those on leaf epidermis. Therefore,it is considered that the outer stomatal rims on tepal epidermis and the outer stomatal rims on leaf epidermis are not interrelated. Neither is the latter nor the habit. The characters of tepal epidermis are constant whether the tepals grow in bisexual, male or female flowers, which means this character does not relate with flower sex. Comparing the characters of tepal epidermis among Illicium,Kadsura and Schisan dra, it is indicated that Schisandra has more derived characters than Kadsura, and so does Kadsura than Illicium. Additionaly, the similarity ,of tepal epidermis between Kadsura and Schisandra, is greater than that between Kadsura and Illicium. Therefore,it seems reasonable to establish Schisandraceae including genera Kadsura and Schisandra, and Illiciaceae only containing the single genus Illicium.