Journal article
Babcock revisited: new insights into generic delimitation and character evolution in Crepis L. (Compositae : Cichorieae) from ITS and matK sequence data
Publication Details
Authors: | Enke, N.; Gemeinholzer, B. |
Publisher: | WILEY |
Publication year: | 2008 |
Journal: | Taxon |
Pages range : | 756-768 |
Volume number: | 57 |
Issue number: | 3 |
Start page: | 756 |
End page: | 768 |
Number of pages: | 13 |
ISSN: | 0040-0262 |
DOI-Link der Erstveröffentlichung: |
Abstract
In 1947 Babcock published his widely acknowledged monograph of the genus Crepis L. including a sectional classification of the species as well as extensive hypotheses about character evolution. To reinvestigate Babcock's evolutionary hypotheses and the generic delimitation of Crepis L. a phylogenetic analysis was conducted using ITS and chloroplast matK Sequence data. The results revealed Crepis L. to be polyphyletic. A monophyletic clade including Central Asian and North American species of Crepis sect. Ixeridopsis is clearly isolated from Crepis s.str. and, as also supported by additional morphological evidence, needs to be transferred to the genus Askellia Weber (1984). A second clade comprising the genera Lapsana L. and Rhagadiolus Juss. as well as a statistically strongly supported clade of several Crepis species is sister to a third clade: the monophyletic Crepis s.str. Within Crepis s.str. the molecular data does not Support Babcock's sectional delimitation which is mainly based on his hypotheses about karyotype evolution. Hence, morphological and karyological characters are re-assessed with regard to the molecular phylogeny.
In 1947 Babcock published his widely acknowledged monograph of the genus Crepis L. including a sectional classification of the species as well as extensive hypotheses about character evolution. To reinvestigate Babcock's evolutionary hypotheses and the generic delimitation of Crepis L. a phylogenetic analysis was conducted using ITS and chloroplast matK Sequence data. The results revealed Crepis L. to be polyphyletic. A monophyletic clade including Central Asian and North American species of Crepis sect. Ixeridopsis is clearly isolated from Crepis s.str. and, as also supported by additional morphological evidence, needs to be transferred to the genus Askellia Weber (1984). A second clade comprising the genera Lapsana L. and Rhagadiolus Juss. as well as a statistically strongly supported clade of several Crepis species is sister to a third clade: the monophyletic Crepis s.str. Within Crepis s.str. the molecular data does not Support Babcock's sectional delimitation which is mainly based on his hypotheses about karyotype evolution. Hence, morphological and karyological characters are re-assessed with regard to the molecular phylogeny.
Keywords
Askellia, Crepis, ITS, matK, phylogeny
