中国壳斗科栎亚科花粉形态研究

本文应用光学显微镜与扫描电子显微镜观察了壳斗科所属栎亚科2属26种2变种的花粉形态,并以本科其它属一些代表种作对比,试图从孢粉学方面为栎亚科的系统分类提供依据。 花粉外壁纹饰在扫描电镜下可分三种类型,即水青冈型(含水青冈属),栎型(含栎属和三棱栎属),栗型(含栗属、锥属和柯属),花粉的类型与植物形态分类的三个亚科一致。 栎亚科的花粉外壁纹饰在扫描电镜下为颗粒聚集成的种种形状。栎属可区分为四种类型,即颗粒状、颗粒——蠕虫状、聚颗粒及芽孢状,其中类型一、二、三为常绿种类,类型四为落叶种类。花粉纹饰在常绿与落叶种类之间有较明显的差异,而青冈亚属和栎亚属之间却没有界线。因此,栎属仍以包含两个亚属为宜。三棱栎属花粉纹饰则介于栎属的类型二与三之间。

A STUDY ON POLLEN MORPHOLOGY OF QUERCOIDEAE OERST (FAGACEAE) IN CHINA

The present paper describes the pollen morphology of 26 species 2 varieties belonging to 2 genera of Quercoideae of Fagaceae from China. The pollen grains were all examined under light microscope and also scanning electron microscope.The pollen grains of the family are prolate, perprolate or subspheroidal, (10.0-47.5)×(8.0-53.5)μ in size, 3-colporate or 3-colpate, membrana colpi; exine 2-layered, 1.5-2.5μ thick, sexine and nexine almost equal. According. to the exine ornamentation under scanning electron microscope the family may divided into three types, i.e. Fagus-Type (the representing genus Fagus): Quercus-Type (Trigonobalanus, Quercus): Castanea-Type (Castanea, Castano-psis, Lithocarpus), and the division is concordant with those classical systems based on the traditionary morphology.The Quercoideae consists of two genera, Trigonobalanus Forman and Quercus L.. The pollen grains of Trigonobalanus are triangular or semilobate, (17.5-30.0)×(17.5-25.0) μ in size, 3-colporate, angulaperturate, pore areaconical prominent, vestibulum. The exine oramentations are granulate-vermiculate.The pollen grains of Quercus are subspheroidal,(20.0-41.7)×(17.0-35.6)μ in size, 3-colporate or 3-colporate. The exine ornamentation under scanning electron microscope can be distinguished into four types: Type- Ⅰ granulate, Type-Ⅱ granulate-vermiculate, Type-Ⅲ aggregate granulate, Type-Ⅳ gemmate. The members of Type Ⅰ-Ⅲ all are evergreen trees or shrubs, including, the species of Subgenus Cyclobalanopsis and Subgenus Quercus. Type-Ⅳ is including all deciduous trees or shrubs. The palynological evidence supports the opinion which Quercus includes the Subgenus Cyclobalanopsis and the Subgenus Quercus.