title: Origin of the invasive Arundo donax (Poaceae): a trans-Asian expedition in herbaria.
abstract: OBJECTIVE
  The hypothesis of an ancient introduction, i.e. archaeophyte origin, is one of the most challenging questions in phylogeography. Arundo donax (Poaceae) is currently considered to be one of the worst invasive species globally, but it has also been widely utilzed by man across Eurasia for millennia. Despite a lack of phylogenetic data, recent literature has often speculated on its introduction to the Mediterranean region.
  
  
  METHODS
  This study tests the hypothesis of its ancient introduction from Asia to the Mediterranean by using plastid DNA sequencing and morphometric analysis on 127 herbarium specimens collected across sub-tropical Eurasia. In addition, a bioclimatic species distribution model calibrated on 1221 Mediterranean localities was used to identify similar ecological niches in Asia.
  
  
  RESULTS
  Despite analysis of several plastid DNA hypervariable sites and the identification of 13 haplotypes, A. donax was represented by a single haplotype from the Mediterranean to the Middle East. This haplotype is shared with invasive samples worldwide, and its nearest phylogenetic relatives are located in the Middle East. Morphometric data characterized this invasive clone by a robust morphotype distinguishable from all other Asian samples. The ecological niche modelling designated the southern Caspian Sea, southern Iran and the Indus Valley as the most suitable regions of origin in Asia for the invasive clone of A. donax.
  
  
  CONCLUSIONS
  Using an integrative approach, an ancient dispersion of this robust, polyploid and non-fruiting clone is hypothesized from the Middle East to the west, leading to its invasion throughout the Mediterranean Basin.
authors: Institut Méditerranéen de Biodiversité et d'Ecologie, UMR CNRS IRD, Aix Marseille Université, 13331 Marseille, France laurent.hardion@imbe.fr.
authors: Laurent
authors: L
authors: Hardion
authors: Institut Méditerranéen de Biodiversité et d'Ecologie, UMR CNRS IRD, Aix Marseille Université, 13331 Marseille, France.
authors: Régine
authors: R
authors: Verlaque
authors: Smithsonian Tropical Research Institute, Apartado 0843-03092, Panama.
authors: Kristin
authors: K
authors: Saltonstall
authors: Institut Méditerranéen de Biodiversité et d'Ecologie, UMR CNRS IRD, Aix Marseille Université, 13331 Marseille, France.
authors: Agathe
authors: A
authors: Leriche
authors: Institut Méditerranéen de Biodiversité et d'Ecologie, UMR CNRS IRD, Aix Marseille Université, 13331 Marseille, France.
authors: Bruno
authors: B
authors: Vila
mesh_terms: D001208:Asia; D005075:Biological Evolution; D018744:DNA, Plant / Q000235:genetics*; D017753:Ecosystem; D018703:Founder Effect; D005819:Genetic Markers; D006239:Haplotypes; D058865:Introduced Species; D019083:Mediterranean Region; D008969:Molecular Sequence Data; D010802:Phylogeny; D063148:Plant Dispersal; D006109:Poaceae / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology*; D011110:Polymorphism, Genetic; D012098:Reproduction; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers
keywords: Arundo donax; Asia; Mediterranean; Poaceae; archaeophyte; clonal species; crops; domesticated species; giant cane; giant reed; herbarium specimens; invasive species; morphometry; phylogeography