Drábková Lenka, Kirschner Jan, Vlček Čestmír
Institute of Botany, Department of Taxonomy, Academy of Sciences, Zámek 1, 252 43 Průhonice, Czech Republic.
Centre for Integrated Genomics and Institute of Molecular Genetics, Academy of Sciences, Flemingovo nám. 2, 166 37 Prague 6, Czech Republic.
Cladistics. 2006 Apr;22(2):132-143. doi: 10.1111/j.1096-0031.2006.00095.x.
Juncus and Luzula are the largest, almost cosmopolitan, genera in the Juncaceae. Relationships within Juncus and Luzula and among other genera of Juncaceae (Distichia, Marsippospermum, Oxychloë, Patosia and Rostkovia) remain incompletely resolved. RbcL sequence data resolved a part of the supraspecific phylogeny, but many clades remain polytomic. For this reason, the non-coding cpDNA regions, trnL intron and trnL-trnF intergenic spacer, were sequenced. We intended to create hypotheses of relationships within Juncaceae and to test the classification of the sections, but a primary goal to this study was to assess the relationships within Juncus and Luzula and to test for monophyly of groups recognized from rbcL data (especially the monophyly of genus Luzula and the Southern Hemisphere Clade (SHC)). Furthermore, we tested the influence of different rooting and ingroup composition on the tree topology. The parsimony analyses revealed several well-supported lineages. The traditionally distinguished genus Luzula is monophyletic and Juncus is non-monophyletic. Two subgenera of Luzula (Pterodes and Luzula) are non-monophyletic, while subg. Marlenia forms a sister group to the whole Luzula clade (trnL-F data set). Within Juncus, both subgenus Juncus and subgenus Agathryon are non-monophyletic. SHC is clustered not only with the South African J. lomatophylus and J. capensis, but also together with members of the section Juncus, Caespitosi and Graminifolii. These sections form a well-separated sister group to the SHC. Within the genera Juncus and Luzula, monophyly is demonstrated for a number of groups (e.g., Juncus section Stygiopsis, Luzula section Luzula) but questioned for others (e.g., Juncus section Graminifolii). The unusual, separate positioning of Juncus trifidus and J. monanthos were clarified by trnL-trnF sequence data, but vary within the tree topology depending on outgroup selection and also due to LBA phenomenon.
灯心草属（Juncus）和地杨梅属（Luzula）是灯心草科中最大的两个属，几乎遍布全球。灯心草属和地杨梅属内部以及灯心草科其他属（双蕊灯草属（Distichia）、种子草属（Marsippospermum）、尖叶灯草属（Oxychloë）、帕托灯草属（Patosia）和罗斯特灯草属（Rostkovia））之间的关系仍未完全厘清。核糖体大亚基RNA（RbcL）序列数据解决了部分科级以上的系统发育问题，但许多分支仍为多歧分支。因此，对非编码叶绿体DNA区域，即trnL内含子和trnL-trnF基因间隔区进行了测序。我们旨在构建灯心草科内部关系的假说，并检验各分类群的分类，但本研究的一个主要目标是评估灯心草属和地杨梅属内部的关系，并检验基于RbcL数据所识别的类群的单系性（特别是地杨梅属和南半球分支（SHC）的单系性）。此外，我们还检验了不同的生根方式和类群组成对树形拓扑结构的影响。简约分析揭示了几个得到充分支持的谱系。传统上区分的地杨梅属是单系的，而灯心草属不是单系的。地杨梅属的两个亚属（翅茎亚属（Pterodes）和地杨梅亚属（Luzula））不是单系的，而Marlenia亚属构成了整个地杨梅属分支的姐妹群（trnL-F数据集）。在灯心草属内，灯心草亚属和Agathryon亚属都不是单系的。南半球分支不仅与南非的宽叶灯心草（J. lomatophylus）和开普灯心草（J. capensis）聚类在一起，还与灯心草组、丛生组和禾本科叶组的成员聚类在一起。这些组形成了一个与南半球分支明显分开的姐妹群。在灯心草属和地杨梅属内，一些类群（如灯心草属的Stygiopsis组、地杨梅属的地杨梅组）表现出单系性，但其他类群（如灯心草属的禾本科叶组）则受到质疑。三裂灯心草（Juncus trifidus）和单花灯心草（J. monanthos）不寻常的单独定位通过trnL-trnF序列数据得到了阐明，但在树形拓扑结构中会因外类群选择以及长枝吸引（LBA）现象而有所不同。
