Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses
Background and Aims The geographic distribution of the genus Plectocephalus comprises a single species in Ethiopia, two in North America and possibly four more in South America, in a striking disjunction that is exceptional for genera of the tribe Cardueae. The enormity of this disjunction cast doub...
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fthighwire:oai:open-archive.highwire.org:annbot:108/2/263 2023-05-15T15:42:42+02:00 Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses Susanna, Alfonso Galbany-Casals, Mercè Romaschenko, Konstantyn Barres, Laia Martín, Joan Garcia-Jacas, Núria 2011-08-01 00:00:00.0 text/html http://aob.oxfordjournals.org/cgi/content/short/108/2/263 https://doi.org/10.1093/aob/mcr138 en eng Oxford University Press http://aob.oxfordjournals.org/cgi/content/short/108/2/263 http://dx.doi.org/10.1093/aob/mcr138 Copyright (C) 2011, Oxford University Press ORIGINAL ARTICLES TEXT 2011 fthighwire https://doi.org/10.1093/aob/mcr138 2016-11-16T19:07:27Z Background and Aims The geographic distribution of the genus Plectocephalus comprises a single species in Ethiopia, two in North America and possibly four more in South America, in a striking disjunction that is exceptional for genera of the tribe Cardueae. The enormity of this disjunction cast doubts on the precise taxonomic delineation of the genus, which is not unanimously recognized as a natural entity. The aims of this study were to define the generic boundaries of Plectocephalus and to formulate a hypothesis that would explain its natural range. Methods A combined molecular approach, using nuclear internal transcribed spacers (ITS) and external transcribed spacers (ETS), and plastid trnL-trnL-F , rpl32-trnL UAG and ndhF markers, was chosen for phylogenetic reconstruction by maximum parsimony and Bayesian inference. Key Results Phylogenetic analysis shows that Plectocephalus is a natural genus that includes the African species P. varians , together with all the native South American species, currently classified as Centaurea , C. cachinalensis , C. floccosa and C. tweediei . The recognition of Centaurodendron as an independent genus, which we consider appropriate, would make Plectocephalus paraphyletic. Affinities of Plectocephalus should lie with eastern representatives of Centaureinae. Geographic disjunction is explained as a consequence of dispersal via the Bering Land Bridge during the Miocene–Pliocene. The phylogeny of the basal grade of Centaureinae differs from previous phylogenies, and artefacts resulting from differences in mutation rates of annual and perennial taxa are confirmed. Sensitivity of ITS to these differences was the highest observed for all DNA regions used in this study. Conclusions The natural status of the genus Plectocephalus is confirmed and several nomenclatural combinations are proposed. New evidence contributes to the debate concerning problems posed by the use of ITS in the phylogenetic reconstruction of groups that differ in terms of their life cycles. Dispersal from Caucasus ... Text Bering Land Bridge HighWire Press (Stanford University) Annals of Botany 108 2 263 277 |
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ORIGINAL ARTICLES |
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ORIGINAL ARTICLES Susanna, Alfonso Galbany-Casals, Mercè Romaschenko, Konstantyn Barres, Laia Martín, Joan Garcia-Jacas, Núria Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses |
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ORIGINAL ARTICLES |
description |
Background and Aims The geographic distribution of the genus Plectocephalus comprises a single species in Ethiopia, two in North America and possibly four more in South America, in a striking disjunction that is exceptional for genera of the tribe Cardueae. The enormity of this disjunction cast doubts on the precise taxonomic delineation of the genus, which is not unanimously recognized as a natural entity. The aims of this study were to define the generic boundaries of Plectocephalus and to formulate a hypothesis that would explain its natural range. Methods A combined molecular approach, using nuclear internal transcribed spacers (ITS) and external transcribed spacers (ETS), and plastid trnL-trnL-F , rpl32-trnL UAG and ndhF markers, was chosen for phylogenetic reconstruction by maximum parsimony and Bayesian inference. Key Results Phylogenetic analysis shows that Plectocephalus is a natural genus that includes the African species P. varians , together with all the native South American species, currently classified as Centaurea , C. cachinalensis , C. floccosa and C. tweediei . The recognition of Centaurodendron as an independent genus, which we consider appropriate, would make Plectocephalus paraphyletic. Affinities of Plectocephalus should lie with eastern representatives of Centaureinae. Geographic disjunction is explained as a consequence of dispersal via the Bering Land Bridge during the Miocene–Pliocene. The phylogeny of the basal grade of Centaureinae differs from previous phylogenies, and artefacts resulting from differences in mutation rates of annual and perennial taxa are confirmed. Sensitivity of ITS to these differences was the highest observed for all DNA regions used in this study. Conclusions The natural status of the genus Plectocephalus is confirmed and several nomenclatural combinations are proposed. New evidence contributes to the debate concerning problems posed by the use of ITS in the phylogenetic reconstruction of groups that differ in terms of their life cycles. Dispersal from Caucasus ... |
format |
Text |
author |
Susanna, Alfonso Galbany-Casals, Mercè Romaschenko, Konstantyn Barres, Laia Martín, Joan Garcia-Jacas, Núria |
author_facet |
Susanna, Alfonso Galbany-Casals, Mercè Romaschenko, Konstantyn Barres, Laia Martín, Joan Garcia-Jacas, Núria |
author_sort |
Susanna, Alfonso |
title |
Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses |
title_short |
Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses |
title_full |
Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses |
title_fullStr |
Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses |
title_full_unstemmed |
Lessons from Plectocephalus (Compositae, Cardueae-Centaureinae): ITS disorientation in annuals and Beringian dispersal as revealed by molecular analyses |
title_sort |
lessons from plectocephalus (compositae, cardueae-centaureinae): its disorientation in annuals and beringian dispersal as revealed by molecular analyses |
publisher |
Oxford University Press |
publishDate |
2011 |
url |
http://aob.oxfordjournals.org/cgi/content/short/108/2/263 https://doi.org/10.1093/aob/mcr138 |
genre |
Bering Land Bridge |
genre_facet |
Bering Land Bridge |
op_relation |
http://aob.oxfordjournals.org/cgi/content/short/108/2/263 http://dx.doi.org/10.1093/aob/mcr138 |
op_rights |
Copyright (C) 2011, Oxford University Press |
op_doi |
https://doi.org/10.1093/aob/mcr138 |
container_title |
Annals of Botany |
container_volume |
108 |
container_issue |
2 |
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263 |
op_container_end_page |
277 |
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1766376653720649728 |