宽翅菘蓝系统发育关系和分类地位研究

宽翅菘蓝(Isatis violascens)是分布于新疆准噶尔盆地的一种早春短命植物。基于形态的相似性,有人建议将宽翅菘蓝作为Isatis emarginata同义体。目前宽翅菘蓝尚未得到分子水平的研究,其系统发育地位也不清楚。该研究对宽翅菘蓝的ITS区进行测序,结合GenBank数据库中菘蓝属物种的ITS序列对宽翅菘蓝的系统关系和分类地位进行研究。最大简约法,最大似然法和贝叶斯法3种方法分析表明:菘蓝属物种聚为两个分支;宽翅菘蓝与I.emarginata和小果菘蓝具有较近的亲缘关系;基于形态相似性和较近的遗传距离,支持将宽翅菘蓝与I.emarginata合并为一个物种,并把宽翅菘蓝作为I.emarginata的同义种。

Phylogenetic Relationship and Taxonomic Status of Isatis violascens Bunge(Isatis,Brassicaceae)

Isatis violascens Bunge is a spring ephemeral plant occurred in the sandy deserts of Junggar (or Dzungaria) Basin.It was suggested as a synonym of Isatis emarginata based on their morphology similarity.I.violascens has not been included in any molecular studies to date and its phylogenetic relationship is unknown.In present study,the nuclear ribosomal internal transcribed spacer(ITS) of I.violascens was sequenced.27 samples representing 18 Isatis species were analyzed using most parsimony,most likelihood and Bayesian method.Two well supported clades of Isatis were confirmed.I.violascens was closely related with I.emarginata and I.minima.From the evidence of similarities of morphology and low distance of ITS sequences,we provisionally agree with the merge of the two species and the reduction of I.violascens to synonym of I.emarginata.