title: Systematics, character evolution, and biogeography of Cistus L. (Cistaceae) based on ITS, trnL-trnF, and matK sequences.
abstract: This paper presents the first phylogenetic hypotheses for the 20 species of Cistus based on plastid (trnL-trnF, matK) and nuclear (ITS) DNA sequence data. Phylogenetic relationships reveal that: (1) Halimium and Cistus form a cohesive, natural group; (2) two major lineages of purple-flowered and white-flowered species are defined, except for the purple-flowered C. parviflorus; (3) monophyly of conspecific populations is congruent with the circumscription of species. Topological congruence between nuclear and plastid phylogenies does not support a predominant reticulate system of evolution in Cistus. Reconstruction of character evolution suggests an increment of number of fruit valves in the Cistaceae from 3 to 12 in a unidirectional manner. In contrast, reproductive characters, such as sepal number, petal color, and style length, evolved multiple times in the course of evolution. A single colonization of Cistus into the Canary Islands appears to be responsible for a lineage of four species sharing a most recent common ancestor with five sepals, purple flowers, styles as long as stamens, and five fruit valves. Species diversity in Cistus (14) and Halimium (8), coupled with sister-group relationships and molecular divergence, lead us to suggest the western Mediterranean as a major center of present-day differentiation, but paleobotanical data indicate an earlier formation of the Cistus-Halimium assemblage in different areas.
authors.affiliation: Royal Botanic Garden of Madrid, CSIC, Plaza Murillo 2, 28014 Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Guzmán
authors.forename: Pablo
authors.initials: P
authors.lastname: Vargas
mesh_terms: D001483:Base Sequence; D001499:Bayes Theorem; D029758:Cistus / Q000033:anatomy & histology* / Q000145:classification / Q000235:genetics*; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D003710:Demography; D035264:Flowers / Q000033:anatomy & histology; D005638:Fruit / Q000033:anatomy & histology; D019083:Mediterranean Region; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D018087:Plastids / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D021903:DNA, Ribosomal Spacer