Phylogeny of the coneflowers and relatives (HeliantheaeĀ : Asteraceae) based on nuclear rDNA internal transcribed spacer (ITS) sequences and chlorplast DNA restriction site data

TitlePhylogeny of the coneflowers and relatives (Heliantheae : Asteraceae) based on nuclear rDNA internal transcribed spacer (ITS) sequences and chlorplast DNA restriction site data
Publication TypeJournal Article
Year of Publication2000
AuthorsUrbatsch LE, Baldwin BG, Donoghue MJ
JournalSystematic Botany
Volume25
Pagination539 - 565
ISSN03636445
KeywordsEVOLUTIONARY BIOLOGY, PLANT SCIENCES
Abstract

The internal transcribed spacer (ITS) region of 18S-26S nuclear ribosomal DNA (rDNA) was sequenced in 65 taxa representing most coneflowers (i.e, species in Dracopis, Echinacea, Ratibida, and Rudbeckia) and other tara representing 21 outgroup genera of tribe Heliantheae. Results of parsimony analysis of the rDNA dataset by itself and in combination with the cpDNA dataset uphold the hypothesis from an earlier cpDNA restriction site study that Echinacea is not closely related to the other three genera of coneflowers. The data support placement of Echinacea in subtribe Zinniinae. The remaining three coneflower genera represent a monophyletic lineage corresponding to subtribe Rudbeckiinae sensu H. Robinson. The rDNA data support two sublineages in Rudbeckia congruent with the two traditionally recognized subgenera, subg. Macrocline and subg. Rudbeckia. In subg. Macrocline, two geographic areas of diversification are indicated: southeastern and western United States. The widespread species

URLhttp://search.ebscohost.com/login.aspx?direct=true&db=edswsc&AN=000089681500011&site=eds-live