Assembly and origin of the flora of the Chihuahuan Desert: the case of sclerophyllous Rosaceae

Aim To test hypotheses on the origin and assembly of the flora of the Chihuahuan Desert using as a system the hard-leaved shrubby lineages of the Rosaceae distributed in North American Deserts.

Location North American Deserts, Chihuahuan Desert, Mexican Plateau, Tehuacán Valley.

Methods Phylogenetic analyses were conducted based on nine chloroplast and nuclear molecular markers of eleven newly sequenced species of Rosaceae distributed in the Chihuahuan Desert along with previous sequences of 41 species in 25 genera representative of the major clades in the family. Based on phylogeny, divergence times, migration, vicariance events and ancestral biogeographic areas were determined. Ecological niche-based modeling will predict changes in distribution during Pleistocene climate oscillations. Traitgrams were constructted to visualize departure among lineages in the most significant climate variables.

Results The lineages studied diverged during the Eocene-Oligocene (53 – 33Mya). Th...