Hybridization as a Stimulus for the Evolution of Invasiveness in Plants
Ainouche, Malika L. .
Hybridization and polyploidy: Lessons from the invasive allopolyploid Spartina anglica..
DUPLICATION of hybrid genomes (i.e. allopolyploidy) is a common speciation mechanism in plants. Recently formed allopolyploid lineages are often characterized by rapid expansion and larger ecological amplitude than their diploid progenitors. Recent genetic and genomic approaches on several systems have greatly improved our understanding of the evolutionary success of allopolyploidy, and increasing data are accumulating revealing the dynamic nature of duplicated genomes at the genetic, epigenetic and expression levels. Here we will examine the respective parts that hybridization (i.e. merger of two divergent genomes) and polyploidisation (i.e. genome duplication) play in this dynamics. We use for this two independently formed natural F1 hybrids in Western Europe salt marshes during the end of the 19th century: Spartina x townsendii in England and S. x neyrautii in France resulting from hybridization between the introduced hexaploid Spartina alterniflora from eastern America and the native west-european hexaploid Spartina maritima, and the allododecaploid Spartina anglica that has formed following genome doubling of S. x townsendii. This latter species has rapidly expanded in range and it has now invaded several continents. The results will be compared to those that have emerged from the recent literature on similar questions.
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1 - University of Rennes 1 UMR CNRS 6553, Evolutionary Ecology - Genome Evolution and Speciation Lab., Bat 14A Campus de Beaulieu, Rennes, 35 042 Cedex, France
Presentation Type: Symposium or Colloquium Presentation
Date: Wednesday, August 2nd, 2006
Time: 9:15 AM