路安民汤彦承.pdf

植 物 分 类 学 报 43 (5): 420–430 (2005) doi:10.1360/aps050019 Acta Phytotaxonomica Sinica ·综述 · 被子植物起源研究中几种观点的思考 路安民 汤彦承 ( 中国科学院植物研究所系统与进化植物学重点实验室 北京 100093) Consideration on some viewpoints in researches of the origin of angiosperms LU An-Ming TANG Yan-Cheng (Laboratory of Systematic and Evolutionary Botany, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China) Abstract In this paper, some viewpoints on the origin of angiosperms are discussed. (1) The angiosperms share certain remarkably consistent character syndrome, and thus it is unlikely that they evolved from more than one ancestor, although they might have a common ancestor group. The angiosperms should be a group of unitary origin. The classification systems of extant angiosperms were constructed based on comprehensive evidence from morphological, molecular systematics, palaeobotanical, and phytogeographical studies, and could only express affinity among the extant angiosperms. At present it is impossible to construct a phylogenetic system that contains all extinct and extant angiosperm groups, and for this reason the classification systems of extant angiosperms can only be considered as “affinity” ones. (2) The evidence from molecular clocks, fossils and geographic distribution data on the origin time of angiosperms has been greatly accumulated in the past two decades. Fossil data are very important for determination of the origin time of angiosperms. However, fossil evidence is only the integrated embodiment for the preserved parts of plants and geological fossilization conditions