ena-STUDY-University of Vienna-23-08-2018-20:43:18:814-100
Phylogeny of the Eurasian genus Jurinea (Asteraceae: Cardueae): Support for a monophyletic genus concept and a first hypothesis on overall species relationships
Jurinea (Asteraceae, Cardueae) is a large Eurasian genus (about 180 species) with centers of diversity in Central and Southwest Asia and the eastern Mediterranean. The genus includes many species with adaptations to xero- and chasmophytic habitats and comprises numerous endemics, especially in the Caucasus. Generic delimitations between Jurinea and closely related genera have been difficult to assess, as have the phylogenetic relationships with the genera Jurinella, Himalaiella and Lipschitziella, each of which has been suggested as congeneric with Jurinea. A molecular phylogenetic investigation at both the specific and the generic level to establish the generic borders of Jurinea and to evaluate the intergeneric relationships of the genus with other members of the Cardueae was hitherto lacking. In this study, we reconstruct the phylogenetic relationships between Jurinea and several closely related genera based on a representative taxon sampling using DNA sequence data of nuclear (ITS and ETS) and plastid DNA regions (trnK/matK, trnL-F). We also evaluate the infrageneric classification of Jurinea. Our results indicate that Jurinea is polyphyletic in its current circumscription, as the species J. gedrosiaca and J. cartilaginea are placed within the subtribe Centaureineae of the Cardueae. The rest of Jurinea is monophyletic and split into two major clades corresponding to the western and eastern range of the distribution area of the genus. The sister clade of Jurinea is composed of Himalaiella and Lipschitziella. Jurinella, which was segregated from Jurinea based on achene morphology, is congeneric with Jurinea. Like in other speciose Eurasian genera, the currently recognized sections do not reflect natural groups, whereas most clades found through molecular phylogenetic inference correlate with geographic patterns. A clade that exclusively comprises Caucasian endemics, including the narrow endemics of J. section Neobellae, was found. This clade represents an interesting study group for possible radiation events of Jurinea in the Caucasus.
Jurinea (Asteraceae, Cardueae) is a large Eurasian genus (about 180 species) with centers of diversity in Central and Southwest Asia and the eastern Mediterranean. The genus includes many species with adaptations to xero- and chasmophytic habitats and comprises numerous endemics, especially in the Caucasus. Generic delimitations between Jurinea and closely related genera have been difficult to assess, as have the phylogenetic relationships with the genera Jurinella, Himalaiella and Lipschitziella, each of which has been suggested as congeneric with Jurinea. A molecular phylogenetic investigation at both the specific and the generic level to establish the generic borders of Jurinea and to evaluate the intergeneric relationships of the genus with other members of the Cardueae was hitherto lacking. In this study, we reconstruct the phylogenetic relationships between Jurinea and several closely related genera based on a representative taxon sampling using DNA sequence data of nuclear (ITS and ETS) and plastid DNA regions (trnK/matK, trnL-F). We also evaluate the infrageneric classification of Jurinea. Our results indicate that Jurinea is polyphyletic in its current circumscription, as the species J. gedrosiaca and J. cartilaginea are placed within the subtribe Centaureineae of the Cardueae. The rest of Jurinea is monophyletic and split into two major clades corresponding to the western and eastern range of the distribution area of the genus. The sister clade of Jurinea is composed of Himalaiella and Lipschitziella. Jurinella, which was segregated from Jurinea based on achene morphology, is congeneric with Jurinea. Like in other speciose Eurasian genera, the currently recognized sections do not reflect natural groups, whereas most clades found through molecular phylogenetic inference correlate with geographic patterns. A clade that exclusively comprises Caucasian endemics, including the narrow endemics of J. section Neobellae, was found. This clade represents an interesting study group for possible radiation events of Jurinea in the Caucasus.