Species divergence and relationships in Stephanomeria (Compositae):: PgiC phylogeny compared to prior biosystematic studies
Species divergence and relationships in Stephanomeria (Compositae):: PgiC phylogeny compared to prior biosystematic studies
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DOI：
10.3732/ajb.93.3.480
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发表时间：
2006-03-01
影响因子：
3
通讯作者：
Gottlieb, LD
中科院分区：
文献类型：
--
作者：
Ford, VS;Lee, J;Gottlieb, LD
我们提出了一个最大似然树41 PgiC序列的单系Stephanomeria，10个多年生和6年生种，广泛分布在北美西部和不同的物种形成过程的典范。系统发育分析代表了首次使用PgiC序列的菊科。一年生种最初是由生物系统学研究界定的，这些研究提供了它们生殖相容性和染色体结构同源性的证据。多年生物种在形态上非常独特，没有被类似地检查过。PgiC树提供了比我们以前的ITS/ETS树更高的分辨率，并反映了过去和正在进行的杂交和/或不完整的谱系分选。在Stephanomeria中解决了两个主要的PgiC分支。一个分支包含来自一年生物种的基因加上多年生的、岛屿特有的S。guadalupensis与单系S.弗吉尼亚。小Stephanomeria exigua不是单系的。第二支包括所有其他采样多年生物种的基因和一个单系亚支的四个基因从两个一年生物种。结果进行了比较，以前的研究，也使用PgiC，Clarkia（柳叶菜科）。分子系统学和生物系统学的方法都是必不可少的，以辨别这两个非常不同的进化过程中，北美西部的研究属。
We present a maximum likelihood tree of 41 PgiC sequences for the monophyletic Stephanomeria, with 10 perennial and six annual species, widely distributed in western North America and exemplary of different speciation processes. The phylogenetic analysis represents the first use of PgiC sequences for Compositae. The annual species were originally delimited by biosystematic studies that provided evidence of their reproductive compatibility and chromosome structural homology. The perennial species are highly distinctive in morphology and have not been examined similarly. The PgiC tree provides more resolution than our previous ITS/ETS tree and reflects both past and ongoing hybridization and/or incomplete lineage sorting. Two major PgiC clades were resolved in Stephanomeria. One clade contains the genes from the annual species plus the perennial, insular endemic S. guadalupensis, which appears closely related to a monophyletic S. virgata. Stephanomeria exigua is not monophyletic. The second clade includes the genes from all other sampled perennial species and a monophyletic subclade of four genes from two annual species. The results are compared to previous studies, also using PgiC, of Clarkia (Onagraceae). Both molecular systematic and biosystematic approaches are essential to discern the very different courses of evolution in these two, well-studied genera of western North America.