Whitton, J , Bain, John F , Whitlock, Michael C .
Geographic patterns of gene flow within and between plant species: examples from the sunflower family.
Studies of hybridization in a range of plant taxa reveal the complex and diverse outcomes of hybridization, including localized and limited gene flow, broad scale introgression, homoploid and polyploid hybrid speciation. The frequency of each of outcomes has been thought of as a function of the strength of reproductive isolation between taxa, which will affect the frequency of hybrid formation and the fitness of hybrids and introgressants. Here we examine geographical patterns of gene flow using an approach based on a modified mantelís test, based on only inter-taxon genetic and geographic distances. The data employed are from a range of marker types and taxa, sampling broadly across the geographic range of the taxa. Some of the pairs of taxa (e.g. Lasthenia) have overlapping ranges and were previously known to hybridize. In other cases (Townsendia), taxa are allopatric and interspecific gene flow had not been reported. We were able to detect evidence for geographical structuring of genetic distances in a number of inter-taxon comparisons, including some previously unsuspected cases of hybridization. We outline the method and its assumptions and explore other possible interpretations, and conclude that the results suggest that unsuspected cases of introgression may be common in plant taxa.
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1 - University of British Columbia, Department of Botany, Vancouver, BC, V6T 1Z4, Canada
2 - University of Lethbridge, Biological Sciences, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
3 - University of British Columbia, Department of Zoology, Vancouver, BC, V6T 1Z4, Canada
Presentation Type: Oral Paper:Papers for Sections
Location: Lake Huron/Hilton
Date: Monday, July 9th, 2007
Time: 3:00 PM