国产蔷薇科李亚科的花粉形态

本文报道了国产李亚科（Prunoideae）10属11种植物花粉形态。花粉近球形至长球形，极轴 20.00－44.12um，赤道轴门17.85-36.95um。极面观三裂圆形，赤道面观椭圆形至圆形。具三孔沟，内孔常为长方形。沟较长，两端较窄。但在 Sinoplagiospermum uniflora中除了3孔沟外，还有周孔沟。花粉外壁明显分化为覆盖层和柱状层，在光学显微镜下表面常模糊，扫描电镜下外壁纹饰均为条纹状。抱粉学结合形态学和细胞学证据说明本亚科为一单系发生的类群。Prinsepia utilis 和Sinoplagiospermum uniflora（Prinsepia uniflora）这两个种在花粉特征和外壁纹饰上差异很大，从而支持将 Prinsepia和 Sinopmplagiospermum分别处理为两个属但不支持将广义的Princepia（含Princepia和Sinoplagiospermum）独立为亚科。此外，由于Exochorda的外壁纹饰同Prunoideae中较原始的类群（如 Laurocerasus）相近，结合细胞学和形态学证据，支持将 Exochord移置至Prunoidea之下。

Pollen Ultrstructure of Pentapylacaceae and Sladeniaceae and Their Relationships to the Family Theaceae

To elucidate taxonomic relationships among the families of Pentapylacaceae,Sladeniaceae and Theaceae,pollen grains of genera,ca.20 species representing three families stated above were examined by light,scanning electron,and transmission electron microscopes.The comparison of pollen morphology shows that the pollen grains of Sladeniaceae are very similar to those.Their pollen grains are oblate to nearly spheroidal and 3- solporate,from rugulate to rugulate -reticulate sculptures and exine structure consisting of thick tectum and columellae,and thin endexine. Howere,the pollen grains of Pentapylacaceae are different relatively from those of Theaceae for having nearly psilate pollen surface and exine structure consising of thin recum,undeveloed columellae and thick endexine though the pollen shape (oblate) and aperture (3-colporate ) are similar to those of Theaceae.As far as the pollen sculpture and exine structure are concerned ,Pentaphylacaceae is more similar to Clematoclethra Maxim. of Actinidiaceae than of Theaceae.