Genetic Analysis of a Broad Hybrid Zone inAesculus(Sapindaceae): Is There Evidence of Long‐Distance Pollen Dispersal?

The genetic structure of a broad hybrid zone involving three hybridizingAesculusspecies,Aesculus flava,Aesculus pavia, andAesculus sylvatica, was examined. The objectives were to assess genetic variability, to test previously reported hypotheses on patterns of gene flow, and to infer the genetic str...

Full description

Saved in:
Bibliographic Details
Published in:International journal of plant sciences 2008-06, Vol.169 (5), p.647-657
Main Authors: Thomas, David T., Ahedor, Adjoa R., Williams, Charles F., dePamphilis, Claude, Crawford, Daniel J., Xiang, Qiu‐Yun (Jenny)
Format: Article
Language:English
Subjects:
Alleles
Gene flow
Genetic loci
Genetic structures
Genetic variation
Hybridity
Microsatellites
Pollen
Population genetics
Taxa
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The genetic structure of a broad hybrid zone involving three hybridizingAesculusspecies,Aesculus flava,Aesculus pavia, andAesculus sylvatica, was examined. The objectives were to assess genetic variability, to test previously reported hypotheses on patterns of gene flow, and to infer the genetic structure and evolutionary processes in the hybrid zone. Samples from 24 populations within parental ranges and the hybrid zone were analyzed for variation at microsatellite and intersimple sequence repeat loci. The results indicated that genetic variability was similar among parental and hybrid populations, indicating no evident increased diversity in the hybrid zone. Most hybrid individuals were genetically more similar toA. sylvaticathan to the other two species, and the overall genetic structure of the hybrid zone is asymmetrically biased towardA. sylvatica. Our analyses supported occasional recurrent long‐distant gene flow fromA. paviaand frequent gene flow fromA. sylvaticainto the hybrid zone, agreeing with results of a previous allozyme study. Collectively, the data from our study and previous allozyme and chloroplast DNA studies indicate that both historical localized gene flow and recurrent long‐distant gene flow have contributed to the existence of the hybrid zone, that is, its origin via historical localized gene flow, while its maintenance involves ongoing long‐distance pollen dispersal.
ISSN:1058-5893
1537-5315
DOI:10.1086/533605