Comparative Genomics, Development, Physiology and Systematics of the Brassicaceae and Cleomaceae
Catalan, Pilar , Inda, Luis , Torrecilla, Pedro , Ruiz, Thirza .
Phylogeny of Cleome L. and its close genera Podandrogyne Ducke and Polanisia Raf. (Cleomoideae, Cleomaceae) based on analysis of nuclear ITS sequences and morphology.
A phylogenetic survey of representatives from all New World and several Old World supraspecific groupings of Cleome, as well as from the closely related Podandrogyne and Polanisia, was conducted based on separate analysis of nuclear ITS sequences and of morphological characters. Both parsimony and Bayesian analyses of the molecular data recognized this group of cleomoid taxa as a strongly supported monophyletic lineage. Podandrogyne was imbedded within a highly supported Andinocleome clade in both analyses. The two analyses either placed Polanisia as a member of a North-American/Old World Cleome s. l. clade or as sister to a Cleome + Podandrogyne clade but with low support in either case. The ITS data indicated the sequential divergence of several basal Old World (sects. Cleome, Gymnogonia, Ranmanissa and Rutidosperma) and North American (subgen. Physospermon, sect. Peritoma) lineages followed by more recent splittings of Central and South American lineages (the Andinocleome (sects. Pterosperma and Rimosperma) group, and sects. Melidiscus and Tarenaya). The morphological data showed extensive homoplasy and did not resolve the phylogeny of these cleomoids. Despite this, several sets of morphological secondary synapomorphies served to characterize the main sectional clades recovered in the molecular tree. Based on the strong support of the Cleome + Podandrogyne + Polanisia clade and the insufficient resolution and low support of the basal branches of this tree, and on the inherent homoplasy and unsatisfactory resolution of the morphological diagnostic traits used to characterize these taxa, a reunification of the three cleomoid genera under a large Cleome s. l. genus would be advisable. A biogeographical interpretation of our molecular phylogeny indicated and earlier origin of the ancestral Cleome lineages in the Old World, followed by colonization of North America and then a subsequent expansion towards central and South-American with more recent secondary radiations in these subcontinents.
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1 - Universidad De Zaragoza, Department De Agricultura, Escuela Politecnica De Huesca, Ctra. Cuarte Km 1, Huesca, E-22071, Spain
2 - University of Zaragoza, Agriculture, High Polytechnic School of Huesca, Ctra. Cuarte km 1, Huesca, Huesca, 22071, Spain
3 - Central University of Venezuela, Botany, Instituto de Botanica Agricola, Maracay, Aragua, Venezuela
Presentation Type: Symposium or Colloquium Presentation
Location: Stevens 2/Hilton
Date: Monday, July 9th, 2007
Time: 1:30 PM