title: Sex Distribution of Paper Mulberry (Broussonetia papyrifera) in the Pacific.
abstract: BACKGROUND
  Paper mulberry (Broussonetia papyrifera (L.) L'Hér. ex Vent) is a dioecious tree native to East Asia and mainland Southeast-Asia, introduced prehistorically to Polynesia as a source of bark fiber by Austronesian-speaking voyagers. In Oceania, trees are coppiced and harvested for production of bark-cloth, so flowering is generally unknown. A survey of botanical records of paper mulberry revealed a distributional disjunction: the tree is apparently absent in Borneo and the Philippines. A subsequent study of chloroplast haplotypes linked paper mulberry of Remote Oceania directly to a population in southern Taiwan, distinct from known populations in mainland Southeast-Asia.
  
  
  METHODS
  We describe the optimization and use of a DNA marker designed to identify sex in paper mulberry. We used this marker to determine the sex distribution in selected localities across Asia, Near and Remote Oceania. We also characterized all samples using the ribosomal internal transcribed spacer sequence (ITS) in order to relate results to a previous survey of ITS diversity.
  
  
  RESULTS
  In Near and Remote Oceania, contemporary paper mulberry plants are all female with the exception of Hawaii, where plants of both sexes are found. In its natural range in Asia, male and female plants are found, as expected. Male plants in Hawaii display an East Asian ITS genotype, consistent with modern introduction, while females in Remote Oceania share a distinctive variant.
  
  
  CONCLUSIONS
  Most paper mulberry plants now present in the Pacific appear to be descended from female clones introduced prehistorically. In Hawaii, the presence of male and female plants is thought to reflect a dual origin, one a prehistoric female introduction and the other a modern male introduction by Japanese/Chinese immigrants. If only female clones were dispersed from a source-region in Taiwan, this may explain the absence of botanical records and breeding populations in the Philippines and Borneo, and Remote Oceania.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.
authors.forename: Johany
authors.initials: J
authors.lastname: Peñailillo
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Olivares
authors.affiliation: Centro de Estudios Avanzados en Zonas Áridas (CEAZA), La Serena, Chile.
authors.forename: Ximena
authors.initials: X
authors.lastname: Moncada
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.
authors.forename: Claudia
authors.initials: C
authors.lastname: Payacán
authors.affiliation: National Museum of Prehistory, Taitung 95060, Taiwan.
authors.forename: Chi-Shan
authors.initials: CS
authors.lastname: Chang
authors.affiliation: Biodiversity Research Center, Academia Sinica, Nangang, Taipei 11529, Taiwan.
authors.forename: Kuo-Fang
authors.initials: KF
authors.lastname: Chung
authors.affiliation: National Museum of Ethnology, Osaka, Japan.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Matthews
authors.affiliation: Escuela de Antropología, Universidad Academia de Humanismo Cristiano, Santiago, Chile.
authors.forename: Andrea
authors.initials: A
authors.lastname: Seelenfreund
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Seelenfreund
mesh_terms: D031623:Broussonetia / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D014644:Genetic Variation; D010140:Pacific Ocean; D063148:Plant Dispersal
chemical_list: D018744:DNA, Plant