Abstract Detail

Population Genetics/Genomics

Villalobos , Adriana Lopez [1], Eckert, Christopher [2].

Does Hybridization Contribute To Range-wide Population Genetic Structure In A Coastal Dune Plant?

Interspecific hybridization can alter the genetic structure of a species’ geographic range, especially when there is geographic variation in the degree of sympatry/parapatry with close relatives. However this hypothesis has rarely been evaluated. The Pacific coastal dune endemic Camissoniopsis cheiranthifolia exhibits strong genetic structure across its geographic range. Sometime genetic subdivisions are concordant with shifts in the mating system from outcrossing to higher levels of self-fertilization, but sometimes not. For instance, large-flowered, self-incompatible (LF-SI) populations are genetically differentiated from closely parapatric, large-flowered, self-compatible (LF-SC) populations despite little difference in mating system and habitat affinities. The pattern of geographic variation in growth form and leaf traits suggests that LF-SI C. cheiranthifolia may have diverged from LF-SC populations via hybridization with the predominantly inland SI sister species C. bistorta. We combined an analysis of geographic variation in spatial proximity between the species based on 1506 herbarium records, with population analyses of genetic structure based on 1209 genotypes at 12 nuclear and 9 chloroplast microsatellite loci from 32 C. cheiranthifolia and 18 C. bistorta populations covering their entire geographic ranges. Consistent with our prediction, LF-SI C. cheiranthifolia is more closely parapatric with C. bistorta than any other group of C. cheiranthfolia populations, including LF-SC populations. Closer parapatry was associated with extensive genetic continuity between LF-SI C. cheiranthifolia and C. bistorta. In fact, the SI populations of both species were indistinguishable genetically within the broader context of geographic variation in C. cheiranthifolia.

1 - Queen's University, Biology, Department of Biology, Biosciences Complex, 116 Barrie Street , Kingston, Ontario, K7L3N6, Canada
2 - Department Of Biology, Department Of Biology, Queen\'s University, 116 Barrie Street, Kingston, ON, K7L 3N6, Canada

Keywords:
gene flow
genetic differentiation
microsatellites
Hybridization
Genetic diversity
outcrossing 
self-incompatible.

Presentation Type: Oral Paper
Session: 38, Population Genetics and Genomics I
Location: 101/Mayo Civic Center
Date: Wednesday, July 25th, 2018
Time: 9:00 AM
Number: 38005
Abstract ID:770
Candidate for Awards:Margaret Menzel Award,Cinq Mars Award