title: Genetic population structure of the alpine species Rhododendron pseudochrysanthum sensu lato (Ericaceae) inferred from chloroplast and nuclear DNA.
abstract: BACKGROUND
  A complex of incipient species with different degrees of morphological or ecological differentiation provides an ideal model for studying species divergence. We examined the phylogeography and the evolutionary history of the Rhododendron pseudochrysanthum s. l.
  
  
  RESULTS
  Systematic inconsistency was detected between gene genealogies of the cpDNA and nrDNA. Rooted at R. hyperythrum and R. formosana, both trees lacked reciprocal monophyly for all members of the complex. For R. pseudochrysanthum s.l., the spatial distribution of the cpDNA had a noteworthy pattern showing high genetic differentiation (FST=0.56-0.72) between populations in the Yushan Mountain Range and populations of the other mountain ranges.
  
  
  CONCLUSIONS
  Both incomplete lineage sorting and interspecific hybridization/introgression may have contributed to the lack of monophyly among R. hyperythrum, R. formosana and R. pseudochrysanthum s.l. Independent colonizations, plus low capabilities of seed dispersal in current environments, may have resulted in the genetic differentiation between populations of different mountain ranges. At the population level, the populations of Central, and Sheishan Mountains may have undergone postglacial demographic expansion, while populations of the Yushan Mountain Range are likely to have remained stable ever since the colonization. In contrast, the single population of the Alishan Mountain Range with a fixed cpDNA haplotype may have experienced bottleneck/founder's events.
authors.affiliation: Department of Life Sciences, National Cheng-Kung University, Tainan 701, Taiwan.
authors.forename: Chi-Chun
authors.initials: CC
authors.lastname: Huang
authors.forename: Kuo-Hsiang
authors.initials: KH
authors.lastname: Hung
authors.forename: Chi-Chuan
authors.initials: CC
authors.lastname: Hwang
authors.forename: Jao-Ching
authors.initials: JC
authors.lastname: Huang
authors.forename: Hung-Du
authors.initials: HD
authors.lastname: Lin
authors.forename: Wei-Kuang
authors.initials: WK
authors.lastname: Wang
authors.forename: Pei-Yin
authors.initials: PY
authors.lastname: Wu
authors.forename: Tsai-Wen
authors.initials: TW
authors.lastname: Hsu
authors.forename: Tzen-Yuh
authors.initials: TY
authors.lastname: Chiang
mesh_terms: D005075:Biological Evolution; D018742:DNA, Chloroplast / Q000235:genetics*; D003710:Demography; D049810:Genetic Speciation; D058974:Phylogeography; D029793:Rhododendron / Q000235:genetics*; D013624:Taiwan
chemical_list: D018742:DNA, Chloroplast