Phylogenetics and cytology of a pantropical orchid genus Polystachya (Polystachyinae, Vandeae, Orchidaceae): Evidence from plastid DNA sequence data

$17.95 plus tax (Refund Policy)

Buy Article:

Abstract:

The pantropical orchid genus Polystachya is the subject of ongoing taxonomic work. We inferred phylogenetic relationships in the genus using 5.3 kb of plastid DNA, for 83 out of ca. 240 species and 12 out of 15 sections, as well as five outgroup species. We also collected ploidy data using chromosome counts and genome size estimates. Bayesian and parsimony trees were congruent with each other and well resolved. Polystachya appears monophyletic based on current sampling, provided that the name P. neobenthamia is used instead of Neobenthamia gracilis for that species. The current sectional classification does not define monophyletic groups, but the present study can be used as the basis for a future sectional classification. Areas postulated as Pleistocene refugia for wet tropical forests in Africa also form centres of diversity for the genus. Biogeographical analyses using DIVA and Lagrange show an early radiation in eastern Africa, followed by separate radiations in eastern and western Africa. Subsequent dispersal from western to eastern Africa has occurred at a much higher rate than from east to west. Dispersal to the Neotropics occurred more than once, and one lineage has spread recently and rapidly throughout the tropics. Polyploidy has occurred several times during the diversification of the genus, most notably in association with the recent pantropical dispersal.

Keywords: LONG-DISTANCE DISPERSAL; PHYLOGENETICS; PLASTID DNA SEQUENCES; POLYPLOIDY; POLYSTACHYA; TROPICAL AFRICA

Document Type: Research Article

Affiliations: 1: Department of Systematic & Evolutionary Botany, University of Vienna, Rennweg 14, Vienna 1030, Austria;, Email: anton.russell@univie.ac.at 2: Department of Systematic & Evolutionary Botany, University of Vienna, Rennweg 14, Vienna 1030, Austria 3: Department of Molecular Biology, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia 4: Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, U.K.

Publication date: April 1, 2010

Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more