基于ITS序列探讨法落海的系统分类学地位

为研究法落海的系统分类地位,检测了法落海以及当归属和独活属共12种代表植物的核糖体DNA ITS序列,并结合GenBank中独活属4种代表植物的ITS序列,以羌活属的羌活(Notopterygium incisum)作为外类群,应用序列特征、遗传距离与系统树分析等方法对法落海的系统分类地位进行了分析。结果表明,依据不同的ITS区序列会得出不同甚至截然相反的结论:若依据ITS1序列,法落海应该归属到当归属;若依据ITS2序列,法落海应该归属到独活属。进一步分析法落海与当归属、独活属植物ITS区序列的碱基组成时发现,法落海在ITS1区拥有当归属植物的序列特征,而其ITS2区拥有独活属植物的序列特征。综上分析,支持法落海是介于当归属与独活属之间的一个分类群的系统分类观点。

Phylogenetic Position of Anegelica apaensis/Heracleum apaense Based on Evidence from ITS Sequences of Nuclear Ribosomal DNA

The phylogenetic position of Angelica apaensis/Heracleum apaense(A.apaensis was used in the following),which belongs to Angelicinae in!Umberlliferae,is controversial.To clear its phylogenetic position,ITS(internal transcribed spacer)sequences from A.apaensis and 16 other species in these two genera(4 of them were from GenBank)were used to compute their genetic distances and to construct phylogenetic trees,Notopterygium incisum was used as the outgroup.Analysis on different ITS regions resulted in contradictory conclusions:analysis on ITS1 sequences indicated that A.apaensis should belong to Ange-lica,while analysis on ITS2 sequence suggested that it belongs to Heracleum.Further studies demonstrated that A.apaensis possessed base sequence characters similar to plants in Angelica in ITS1 region,but had base sequence characters similar to plants in Heracleum in ITS2 region.Therefore,results of this study support the view that A.apaensis is a transitional taxon between Angelica and Heracleum.