title: Understanding population structure and historical demography in a conservation context: population genetics of the endangered Kirengeshoma palmata (Hydrangeaceae).
abstract: OBJECTIVE
  Both historical and contemporary microevolutionary processes greatly influence the genetic patterns of East Asian plant endemics, but the spatial and temporal contexts of these processes remain poorly understood. Here, we investigate the relative influences of historical and contemporary gene flow and drift on the population genetic structure of Kirengeshoma palmata, a perennial herb from East China and South Japan.
  
  
  METHODS
  We used data from nine polymorphic microsatellite loci to assess the levels of genetic diversity, effective population size, and contemporary and historical gene flow for six of the seven known populations.
  
  
  RESULTS
  We found high levels of inbreeding and allelic diversity within populations. Both contemporary and historical migration rates among populations were low, and a test of alternate models of population history strongly favored a model of long-term drift-migration equilibrium. We inferred declines in population size ca. 10,000-100,000 yr ago, but failed to detect recent declines. Bayesian clustering divided K. palmata populations into three genetic clusters, two of which were consistent with a glacial refugium hypothesis for two mountain ranges in East China.
  
  
  CONCLUSIONS
  These results suggest that anthropogenic fragmentation has had little effect on the genetic characteristics of Chinese K. palmata. Rather, past decline in population size due to Late Pleistocene climate change as well as restricted pollen and seed dispersal may have contributed to low levels of both historical and contemporary gene flow, resulting in high genetic differentiation between adjacent mountain ranges due to genetic drift and inbreeding.
authors.affiliation: Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, and College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Na
authors.initials: N
authors.lastname: Yuan
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Comes
authors.forename: Cheng-Xin
authors.initials: CX
authors.lastname: Fu
authors.forename: Ying-Xiong
authors.initials: YX
authors.lastname: Qiu
mesh_terms: D002681:China; D003247:Conservation of Natural Resources; D003710:Demography; D017753:Ecosystem; D056727:Endangered Species; D051456:Gene Flow; D040342:Genetic Structures; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D029628:Hydrangeaceae / Q000235:genetics* / Q000502:physiology; D007564:Japan; D018895:Microsatellite Repeats / Q000235:genetics; D058614:Seed Dispersal
keywords: Hydrangeaceae; Kirengeshoma palmata; effective population size; historical and contemporary gene flow; microsatellites; population differentiation