基于叶绿体DNA trnL内含子序列数据的檀香目科间系统发育关系的研究

Interfamilial Relationships of Santalales as Revealed by Chloroplast trnL Intron Sequences

摘要:

应用叶绿体DNAtrnL内含子序列分析檀香目科间的系统发育关系。取样研究的檀香目个体的trnL内含子序列长度在科间呈现较大差异(从291bp到587bp)。最大简约性分析产生的严格一致树与以前已发表的基于其它基因的檀香目的分子系统学研究结果大体一致。香芙木属(铁青树科)是最早分支出的类群;桑寄生科、槲寄生科分别表现为单系类群,檀香科为并系;桑寄生科和槲寄生科并不具密切亲缘关系,槲寄生科从檀香科内衍生出来。本研究表明,具相对高的核苷酸替换率的叶绿体DNAtrnL内含子序列可为高等级类群系统发育关系的研究提供更多的信息位点。

Abstract:

Interfamilial relationships of Santalales were investigated using chloroplast intron sequences. The lengths of trnL intron regions present considerable variation among the sampled Santalalean families, varying from 291 to 587 bp. The topology of strict consensus tree generated from parsimony analysis is largely congruent with trees previously published based on DNA sequences of other genes, which revealed the basal position of Schoepfia (Olacaceae), the monophyly of Loranthaceae and Viscaceae, and the paraphyly of Santalaceae．Loranthaceae are distinct from Viscaceae，the latter is derived from within Santalaceae．Our study also demonstrates the utility of the rapidly evolved chloroplast trnL intron for addressing relationships among the component taxa of San talales.