INVESTIGADORES
ZULOAGA Fernando Omar
artículos
Título:
A molecular phylogeny of Pennisetum and Cenchrus (Poaceae-Paniceae) based on the trnL-F, rpl16 chloroplast markers
Autor/es:
DONADÍO, S., GIUSSANI, L.M., KELLOGG, E.A., F.O. ZULOAGA & O. MORRONE
Revista:
TAXON
Editorial:
INT ASSOC PLANT TAXONOMY
Referencias:
Año: 2009 vol. 58 p. 392 - 404
ISSN:
0040-0262
Resumen:
Pennisetum (80140 species) and Cenchrus (1622 species) are closely 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, 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 and Bayesian inference. Selected geographical,
chromosomal and 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. Our molecular phylogenetic results show a close relationship
among the domesticated species P. glaucum, 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. 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.str.
KEYWORDS: bristle clade, Cenchrus, molecular phylogeny, Pennisetum, rpl16, trnL-F