School of Botany, University of Melbourne, Parkville, Melbourne, Victoria 3052, Australia.
Am J Bot. 2004 Mar;91(3):321-31. doi: 10.3732/ajb.91.3.321.
The taxonomic status of and evolutionary relationship between Tasmannia and Drimys (Winteraceae) have been subjects of controversy for many years. In this paper, a molecular phylogenetic analysis of the family with sequences of previously unpublished Tasmannia and Drimys species confirms earlier conclusions that Tasmannia and Drimys do not form a monophyletic group, despite the fact that they appear to share distinctive inflorescence and floral morphological attributes. Examination of alternative hypotheses of relationships with likelihood-ratio tests and parametric bootstrapping supports the separation of Tasmannia and Drimys. A detailed analysis of floral development in Tasmannia lanceolata and T. xerophila indicates that timing and position of sepal initiation differs between them, but that the position of subsequent organ initiation predictably follows from sepal position. This is in contrast to Drimys winteri, where a prolonged delay between sepal and petal initiation leads to the production of many phyllotactic patterns. The prolonged period of calyx tube growth leading to the formation of a calyptra in Tasmannia and Drimys probably evolved in parallel in the two lineages.
塔斯曼尼亚植物属和 Drimys（樟科）之间的分类地位和进化关系多年来一直存在争议。本文通过对该科植物的分子系统发育分析，结合之前未发表的 Tasmannia 和 Drimys 物种序列，证实了先前的结论，即 Tasmannia 和 Drimys 并非单系群，尽管它们似乎具有独特的花序和花部形态特征。通过似然比检验和参数自举检验对替代关系假说的检验，支持了 Tasmannia 和 Drimys 的分离。对 Tasmannia lanceolata 和 T. xerophila 花发育的详细分析表明，它们的萼片起始时间和位置不同，但随后器官的起始位置可以根据萼片的位置来预测。这与 Drimys winteri 形成对比，在 Drimys winteri 中，萼片和花瓣起始之间的长时间延迟导致产生了许多叶序模式。在 Tasmannia 和 Drimys 中，花萼管的长时间生长导致了帽状体的形成，这可能是这两个谱系平行进化的结果。
