title: Consecutive five-year analysis of paternal and maternal gene flow and contributions of gametic heterogeneities to overall genetic composition of dispersed seeds of Pinus densiflora (Pinaceae).
abstract: OBJECTIVE
  Genetic variability in monoecious woody plant populations results from the assemblage of individuals issued from asymmetrical male and female reproductive functions, produced during spatially and temporarily heterogeneous reproductive and dispersal events. Here we investigated the dispersal patterns and levels of genetic diversity and differentiation of both paternal and maternal gametes in a natural population of Pinus densiflora at the multiple-year scale as long as five consecutive years. •
  
  
  METHODS
  We analyzed the paternity and maternity for 1576 seeds and 454 candidate adult trees using nuclear DNA polymorphisms of diploid biparental embryos and haploid maternal megagametophytes at eight microsatellite loci. •
  
  
  RESULTS
  Despite the low levels of genetic differentiation among gamete groups, a two-way AMOVA analysis showed that the parental origin (paternal vs. maternal gametes), the year of gamete production and their interaction had significant effects on the genetic composition of the seeds. While maternal gamete groups showed a significant FST value across the 5 years, this was not true for their paternal counterparts. Within the population, we found that the relative reproductive contributions of the paternal vs. the maternal parent differed among adult trees, the maternal contributions showing a larger year-to-year fluctuation. •
  
  
  CONCLUSIONS
  The overall genetic variability of dispersed seeds appeared to result from two sources of heterogeneity: the difference between paternal and maternal patterns of reproduction and gamete dispersal and year-to-year heterogeneity of reproduction of adult trees, especially in their maternal reproduction.
authors.affiliation: Kansai Regional Breeding Office, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, 1043, Uetsukinaka, Shoo, Katsuta, Okayama 709-4335, Japan.
authors.forename: Masakazu G
authors.initials: MG
authors.lastname: Iwaizumi
authors.forename: Makoto
authors.initials: M
authors.lastname: Takahashi
authors.forename: Keiya
authors.initials: K
authors.lastname: Isoda
authors.forename: Frédéric
authors.initials: F
authors.lastname: Austerlitz
mesh_terms: D051456:Gene Flow; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics; D056771:Ovule / Q000235:genetics / Q000502:physiology; D028223:Pinus / Q000235:genetics* / Q000502:physiology; D011058:Pollen / Q000235:genetics / Q000502:physiology; D012098:Reproduction; D058614:Seed Dispersal; D012639:Seeds / Q000235:genetics* / Q000502:physiology; D014197:Trees
keywords: Pinaceae; Pinus densiflora; maternal gamete; megagametophyte; paternal gamete; seed dispersal stage; two-way AMOVA