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DNA from bird‐dispersed seed and wind‐disseminated pollen provides insights into postglacial colonization and population genetic structure of whitebark pine ( Pinus albicaulis )
Author(s) -
Richardson B. A.,
Brunsfeld S. J.,
Klopfenstein N. B.
Publication year - 2002
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1046/j.1365-294x.2002.01435.x
Subject(s) - biology , genetic structure , biological dispersal , ecology , phylogeography , population , range (aeronautics) , analysis of molecular variance , seed dispersal , gene flow , mitochondrial dna , evolutionary biology , haplotype , pollen , genetic variation , phylogenetics , genetics , demography , materials science , sociology , gene , genotype , composite material
Uniparentally inherited mitochondrial (mt)DNA and chloroplast (cp)DNA microsatellites (cpSSRs) were used to examine population genetic structure and biogeographic patterns of bird‐dispersed seed and wind‐disseminated pollen of whitebark pine ( Pinus albicaulis Engelm.). Sampling was conducted from 41 populations throughout the range of the species. Analyses provide evidence for an ancestral haplotype and two derived mtDNA haplotypes with distinct regional distributions. An abrupt contact zone between mtDNA haplotypes in the Cascade Range suggests postglacial biogeographic movements. Among three cpSSR loci, 42 haplotypes were detected within 28 cpSSR sample populations that were aggregated into six regions. Analysis of molecular variance ( amova ) was used to determine the hierarchical genetic structure of cpSSRs. amova and population pairwise comparisons ( F ST ) of cpSSR, and geographical distribution of mtDNA haplotypes provide insights into historical changes in biogeography. The genetic data suggest that whitebark pine has been intimately tied to climatic change and associated glaciation, which has led to range movements facilitated by seed dispersal by Clark’s nutcracker ( Nucifraga columbiana Wilson). The two hypotheses proposed to explain the genetic structure are: (i) a northward expansion into Canada and the northern Cascades in the early Holocene; and (ii) historical gene flow between Idaho and the Oregon Cascades when more continuous habitat existed in Central Oregon during the late Pleistocene. Genetic structure and insights gained from historical seed movements provide a basis on which to develop recovery plans for a species that is at risk from multiple threats.