【摘要】 对主要分布于南美和新西兰的南水青冈属Ｎｏｔｈｏｆａｇｕｓ花粉外壁的超微结构进行了观察和研究，同时与壳斗科其他属花粉外壁的结构进行比较，结果表明，南水青冈属花粉外壁的厚度、结构、萌发孔类型以及花粉外壁表面的纹饰与壳斗科其他属花粉外壁的超微结构存在明显差别。主要表现为：南水青冈属花粉外壁的柱状层和内层发育差，为颗粒状；基层和覆盖层无分化结构；覆盖层上为刺状纹饰；萌发孔为５～８沟。壳斗科其他属花粉外壁的小柱发育好，形成明显的柱状层；覆盖层和基层常具一定的结构；花粉表面较光滑，或为波状、颗粒或瘤状纹饰；内层发育较好；多数花粉具３孔沟，少数为３沟或３拟孔沟。本研究认为南水青冈属花粉外壁的结构属于较原始类型，支持Ｋｕｐｒｉａｎｏｖａ等将南水青冈属独立为南壳斗科。更多还原

【Abstract】 The genus Nothofagus is mainly distributed in South America and New Zealand. The present paper describes its pollen exine ultrastructure and compares the exine ultrastructure with that of the other genera of Fagaceae.The pollen grains were examined using ultrathin sectioning technique under transmission electron microscope. The study shows that the pollen exine ultrastructure of Nothofagus differs from that of the other genera of Fagaceae by its exine structure and thickness,type of aperture,and ornamentation. The pollen exine of Nothofagus is thin and possesses granular bacules, regular foot layer and tectum,spinulate ornamentation,and the endexine is usually visible at poral area, and 5～8 colpate. The pollen exine of the other genera of Fagaceae possesses entire bacules, irregular foot layer and tectum,granulate and tuberculate ornamentation,thicker endexine,and is 3 colporate (3 colpate or 3 colporoidate). The pollen exine ultrastructure of Nothofagus may belong to primitive type. The pollen exine ultrastructure data support Kuprianova′s opinion that Nothofagus should be separated from Fagaceae and established as a monogenetic family, i.e. Nothofagaceae.更多还原