木兰科7种植物花粉的扫描电镜观察

在扫描电子显微镜下对木兰科4属7种植物的花粉表面微形态进行了观察和研究,其中3种为首次报道。结果表明,7种植物的花粉均为长球形,为远极单沟花粉,两侧对称,均有穿孔或疣状突起。4属有明显的属间差异,鹅掌楸属穿孔大而显著为典型的穴-网状纹饰,含笑属具穿孔或小穴拟网状纹饰,木兰属外壁平滑具稀疏的小孔或疣状突起,木莲属具不同程度的网格状的纹饰。根据花粉的极轴长度(P)、P/E值的大小和外壁纹饰的类型,证实木兰属和含笑属较进化,木莲属和鹅掌楸属较原始,和花粉形态的分析结果一致。

Pollen morphology of seven Magnoliaceae species under a scanning electron microscope

Pollen morphology of seven species in four genera of Magnoliaceae was studied using a scanning electron microscope (SEM), of which three were firstly reported. The results indicated that all the pollens of these species were long spherical, single ditch in polar view, bilaterally symmetrical, and with perforation or verrucate. There were significant differences in pollen morphology of these four genera: the perforates of Liriodendron pollen were perforated large and with typical hole-mesh ornamentations; while the Michelia pollen were small and with small mesh ornamentations; the Magnolia pollen were smooth and with sparse holes or verrucous protuberances, while the Manglietia pollen were with grid ornamentations in different degrees. Based on the polar axis length (P), the size of P/E, and the type of external wall decoration, the Manglietia and Liriodendron were suggested to be more primitive than Magnolia and Michelia, which were consistent with the results of pollen morphology analysis.