Clement Wendy L, Arakaki Mónica, Sweeney Patrick W, Edwards Erika J, Donoghue Michael J
Department of Biology, The College of New Jersey, 2000 Pennington Rd, Ewing, New Jersey 08628 USA.
Facultad de Ciencias Biológicas and Museo de Historia Natural, UNMSM, Av. Arenales 1256, Apdo. 14-0434, Lima 14, Perú Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, Rhode Island 02912 USA.
Am J Bot. 2014 Jun 1;101(6):1029-1049. doi: 10.3732/ajb.1400015. Epub 2014 Jun 13.
• Premise of the study: Despite recent progress, significant uncertainties remain concerning relationships among early-branching lineages within Viburnum (Adoxaceae), prohibiting a new classification and hindering studies of character evolution and the increasing use of Viburnum in addressing a wide range of ecological and evolutionary questions. We hoped to resolve these issues by sequencing whole plastid genomes for representative species and combining these with molecular data previously obtained from an expanded taxon sample.• Methods: We performed paired-end Illumina sequencing of plastid genomes of 22 Viburnum species and combined these data with a 10-gene data set to infer phylogenetic relationships for 113 species. We used the results to devise a comprehensive phylogenetic classification and to analyze the evolution of eight morphological characters that vary among early-branching lineages.• Key results: With greatly increased levels of confidence in most of the early branches, we propose a phylogenetic classification of Viburnum, providing formal phylogenetic definitions for 30 clades, including 13 with names recognized under the International Code of Nomenclature for Algae, Fungi, and Plants, eight with previously proposed informal names, and nine newly proposed names for major branches. Our parsimony reconstructions of bud structure, leaf margins, inflorescence form, ruminate endosperm, extrafloral nectaries, glandular trichomes, palisade anatomy, and pollen exine showed varying levels of homoplasy, but collectively provided morphological support for some, though not all, of the major clades.• Conclusions: Our study demonstrates the value of next-generation plastid sequencing, the ease of creating a formal phylogenetic classification, and the utility of such a system in describing patterns of character evolution.
• 研究前提：尽管最近取得了进展，但荚蒾属（五福花科）早期分支谱系之间的关系仍存在重大不确定性，这妨碍了新的分类，阻碍了性状进化研究，也阻碍了荚蒾属在解决广泛生态和进化问题方面的日益广泛应用。我们希望通过对代表性物种的整个质体基因组进行测序，并将这些数据与之前从扩大的分类群样本中获得的分子数据相结合，来解决这些问题。
• 方法：我们对22种荚蒾属植物的质体基因组进行了双末端Illumina测序，并将这些数据与一个包含10个基因的数据集相结合，以推断113个物种的系统发育关系。我们利用这些结果设计了一个全面的系统发育分类，并分析了早期分支谱系中变化的八个形态性状的进化。
• 关键结果：随着大多数早期分支的置信度大幅提高，我们提出了荚蒾属的系统发育分类，为30个分支提供了正式的系统发育定义，其中包括13个在《藻类、真菌和植物国际命名法规》下认可的名称，8个之前提出的非正式名称，以及9个新提出的主要分支名称。我们对芽结构、叶缘、花序形式、嚼烂状胚乳、花外蜜腺、腺毛、栅栏组织解剖结构和花粉外壁的简约重建显示出不同程度的同塑性，但总体上为一些（尽管不是全部）主要分支提供了形态学支持。
• 结论：我们的研究证明了下一代质体测序的价值、创建正式系统发育分类的简便性以及这样一个系统在描述性状进化模式方面的实用性。
