Orchid Biology: Darwin`s Contrivances 150 Years Later
Fay, Michael , Chochai, Araya , Leitch, Ilia , Ingrouille, Martin .
Molecular phylogenetics of Paphiopedilum (Cypripedioideae; Orchidaceae) based on nuclear ribosomal ITS and plastid sequences.
Phylogenetic relationships within the genus Paphiopedilum were studied using nuclear ribosomal ITS and plastid sequence data. The results confirm that Paphiopedilum is monophyletic. The division of the genus into three subgenera (Parvisepalum, Brachypetalum and Paphiopedilum) is well supported. All five sections of subgenus Paphiopedilum (Coryopedilum, Pardalopetalum, Cochlopetalum, Paphiopedilum and Barbata) as recognised in the infrageneric treatment of Cribb (1998) are recovered, four with strong support. Section Coryopedilum received low bootstrap but high posterior probability values for support of monophyly. Relationships within section Barbata remain unresolved, and short branch lengths and the narrow geographical distribution of many species in the section suggest that it possibly underwent rapid radiation. Mapping chromosome and genome size data onto the phylogenetic framework shows that there is no clear trend in increase in chromosome number within the genus. However, the diploid chromosome number of 2n = 26 in subgenera Parvisepalum and Brachypetalum suggests this is the ancestral condition, and higher chromosome numbers in sections Cochlopetalum and Barbata suggest that centric fission has occurred in parallel in these sections. The trend for genome size evolution is also unclear, although species in section Barbata generally have larger genome sizes than those in other sections.
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1 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Kew, Richmond, N/A, TW9 3DS, United Kingdom
2 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Richmond, Surrey, TW9 3DS, UK
3 - Royal Botanic Gardens - Kew, Jodrell Laboratory, Richmond, Surrey, TW9-3AB, United Kingdom
4 - Birkbeck, University of London, Biological Sciences, London, WC1E 7HX, UK
Presentation Type: Symposium or Colloquium Presentation
Location: Franklin B/Hyatt
Date: Wednesday, July 11th, 2012
Time: 3:30 PM