杉科植物花粉形态的研究

杉科(Taxodiaceac)是裸子植物的重要科之一。全科共有10属16种。本文用光学显微镜和扫描电镜观察了本科7属10种植物花粉,并用透射电镜研究了其中5个属代表种的外壁内部的超微结构。

STUDIES ON POLLEN MORPHOLOGY OF TAXODIACEAE

There are 10 genera and 16 species of Taxodiaceae. The pollen grains of 10 species belonging to 7 genera in the family were examined with light microscope and scanning electron microscope, and those of representing species of 5 genera with transmission electron microscope. The pollen grains spheroidal or subspheroidal. Size (18.3-38.7)×(20.8-38.4)μ,with one distinct papilla in distal face,individual species indistinct or lacking. Exine rather thin, in general 1-2.5μ thick, layers obvious, sometimes obscure, corsely verrucate, and finely and densely granulate, tuberculate and rugulate. Thin section reveals that endexine is of lamellate structure and extexine is made of granulate layer connecting with each other and sparse larger verrucae of hollowed centre. Pollen grains of Sciadopitys verticillata are very special, and lacking of its papilla in distal face. Surface with rugulate ornamentation. This feature can be distinguished from pollen grains other genera in Taxodiaceae. According to information of pollen morphology, the author suggests that Sciadopitys ver-ticillata could be separated from Taxodiaceae and raise it to the level of family. Pollen grains of Sequoia are special, the thin sections reveal that exine contain tectum and granulate colume-llae. The pollen grains of this family are differentiated from those of Gymnosperms without sacci, with an obvious papilla in distal face.