XVI International Botanical Congess

Spartina anglica arose around 1890 in Southern England, following hybridization between the indigenous Spartina maritima and the eastern North American introduced Spartina alterniflora.In France, S. anglica has first been recorded in 1906 in Cotentin, and now, the species has colonized all along the western coast. Using molecular markers, we show that one major clone occurs in populations from Brittany (France), which is identical to the first generation hybrid Spartina x townsendii from Southern England. This genotype displays nuclear sequence additivity of both parental species and chloroplast DNA sequences identical to S. alterniflora, the maternal genome donnor. However, a few new genotypes are encountered in some populations, suggesting that the allopolyploid is undergoing genomic changes.