生花植物概念简介及其名称的商榷

在上个世纪最后的 2 0年里 ,系统学家应用形态性状对种子植物进行了大量的分支分析。其结果显示灭绝的五柱木属加上灭绝的本内苏铁目及尚存的买麻藤目是被子植物的姊妹群 ,形成一个强支 ,称之为生花植物支。生花植物假说对探讨被子植物起源有着重要影响 ,它激发人们讨论被子植物起源时间可能要提前到三叠纪甚至石炭纪 ,除了支持原有的真花学说外 ,还提出新恩格勒学说。但是 ,近年来对现存种子植物进行分子系统学研究的结果是 :(1)拒绝接受生花植物概念 ;(2 )买麻藤目并不是被子植物的姊妹群而是松柏目的姊妹群 ,甚至网结于松柏类而成为松科的姊妹群。这些结果并不使人惊讶 ,因为对探讨像包含许多灭绝类群的种子植物系统 ,决不可能是仅仅单独应用现代类群资料所能完成的。假如生花植物支是成立的 ,但其名称以AGPB支代替生花植物支可能较为合理。

A Brief Introduction to Anthophyte Concept and Discussion on Its Name

In the last 2 decades of 20~(th) century,a great number of cladistic studies of seed plants using morphological characters have been carried out.The results show that extinct Pentoxylon plus extinct Bennettiales and extant Gnetales is the sister group of angiosperms,and they form a robust clade termed anthophyte clade.The anthophyte hypothesis has played a significant role on the investigation of the origin of angiosperms.It stimulates the discussion on the time of the origin of angiosperms which dated back as early as the Triassic or even the Carboniferous.The hypothesis proposes the Neo-Englerian theory except supporting previous Euanthial theory for the origin of angiosperms. However many recent outcomes of molecular phylogenetic studies of extant seed plants are:(1)refutation of anthophyte concept;(2)Gnetales not as the sister group of angiosperms but as the sister group of conifers or even nested within in conifers and then the sister group to Pinaceae.These results are certainly not surprising,because the phylogeny cannot be discerned with extant taxa alone for such seed plants consisting of many extinct taxa.The anthophyte may be a valid clade but its name is inappropriate.In substitution of the name of AGPB clade (acronym of Angiospermae,Gnetales,Pentoxylon and Bennettiales) for anthophyte clade may be reasonable.