TreeBASE Search-Analyses for study 2136

@ARTICLE{TreeBASE2Ref15272, author = {Sabina Donad?o and Liliana M. Giussani and Elizabeth A. Kellogg and Fernando O. Zuloaga and Osvaldo Morrone}, title = {A preliminary molecular phylogeny of Pennisetum and Cenchrus (Poaceae-Paniceae) based on the trnL-F, rpl16 chloroplast markers}, year = {2008}, keywords = {}, doi = {}, url = {}, pmid = {}, journal = {Taxon}, volume = {}, number = {}, pages = {}, abstract = {Pennisetum (80--140 species) and Cenchrus (16--22 species) are close related genera of Paniceae, both distributed in tropical and sub-tropical regions. The distinction between Pennisetum and Cenchrus is not clearly defined, and currently, no comprehensive taxonomic treatment is available for either genus. Chloroplast DNA sequence data (rpl16 and trnL-F region) were analyzed to test their monophyly, species relationships, and infrageneric classifications. Phylogenetic analyses of individual genomic regions, and a combined dataset, including indel-coded information, were performed under parsimony. Bayesian inference analyses were also performed for the individual and combined datasets. Selected geographical, chromosomal and diagnostic morphological characters were mapped onto the phylogeny to investigate evolutionary trends. Our results support a monophyletic bristle clade and the close relationship between Pennisetum and Cenchrus. Excluding Pennisetum lanatum, Pennisetum is paraphyletic because Cenchrus is nested within it. Sections Pennisetum and Gymnotrix are polyphyletic, while the relationship of other sections and the diagnostic characters used to identify infrageneric taxa, are also discussed. Our molecular phylogenetic results show a close relationship among the domesticated species P. glaucum, and P. purpureum, P. squamulatum, P. nervosum, and P. sieberianum, suggesting the potential use of these species in crop improvement. The Pennisetum-Cenchrus clade shows an independent reduction ( x = 5, 7, 8 ) or duplication ( x = 17 ) of the basic chromosome number from the ancestral x = 9. American Pennisetum and Cenchrus species appear to have originated from Old World species more than once during the evolution. A core group of American species of Cenchrus with a basic chromosome number of x = 17, and retrorsely barbed bristles could be restricted to Cenchrus s.s.} }