毛莨科子叶节区研究与被子植物的中柱演化

STUDIES ON COTYLEDON NODE IN RANUNCULACEAE AND THE EVOLUTION OF THE STELE OF ANGIOSPERM

经毛莨科子叶节区研究确认,被子植物的真中柱,既非来自管状中柱,也非来自原生中柱,而系来自子叶节区保留的单中柱。本文在新发表的同科5个属及其代表种的子叶节区研究的基础上,还公布了一张被子植物中柱演化图。

The Types and the Evolutionary Ways of Steles of Angiosperms Fromthe phylogenic pointof view, the mesarch and diarch to polyarch haplosteleremaining in the lower part of CNZ of angiosperms has developed from theprimitive centrarch protostele like that in Rhyniophyta (Gifford and Foster1988). But from the ontogenic point of view, both of the eustele of the stemand the actinostele of the root has derivatived from the haplostele in thelower part of CNZ. In the process of evolution of angiosperms 'because ofof the complexities of the environment and the protocambium cyl- inder and the changes of the differentiational direction of the protocambiumcylinder, the eustele has developed into bicollateral eustele, amphicribraleustele, hysterostele, atactostele and amphivasal-atactostele.