Molecular systematics of the Umbelliferae: using nuclear ribosomal DNA internal transcribed spacer sequences to resolve issues of evolutionary relationships.

摘要

Phylogenetic relationships among 79 species (58 genera) of Umbelliferae (Apiaceae), representing all 3 subfamilies, and 9 species from outgroup families Araliaceae, Pittosporaceae, Sambucaceae [Caprifoliaceae] and Rosaceae, were inferred from nucleotide sequence variation in the two internal transcribed spacer (ITS1 and ITS2) regions of 18S-26S nuclear ribosomal DNA. Relationships inferred using the neighbour-joining method of tree construction differed drastically from those implied in any existing systems of classification for Umbelliferae. While the results supported the monophyly of Umbelliferae subfamilies Saniculoideae and Apioideae and their sister-group status, subfamily Hydrocotyloideae (represented by only the genus Hydrocotyle) allied with Araliaceae and not with other Umbelliferae. Furthermore, with the exceptions of Apioideae tribes Scandiceae, Caucalideae and Tordylieae, all other previously accepted tribes in the subfamily were not monophyletic. Based on these preliminary analyses,it is evident that the taxonomy of Umbelliferae requires radical revision.