The spread of invasive plant species in natural habitats has become a worldwide problem with negative impacts. Phalaris arundinacea, an important forage and ornamental crop, is widespread worldwide. In recent years there has been a massive spread of P. arundinacea across North America and Canada. Production of Phalaris seed as a forage crop occurs in northern Minnesota; seeds are sold throughout the world, particularly in central Europe. We tested genetic similarities and differences between populations in the US (Minnesota) and the Czech Republic using ISSRs to determine potential gene flow for this forage crop. The cultivated forage and wild genotypes were dispersed into two groups that overlapped. At least four sets of wild US genotypes are dissimilar to European counterparts and potentially native to N. America. Future work to prove the ancestry of each accession will be necessary. Nonetheless, the sale of forage cultivars related to or derived from European types causes genetic mixing with N. American types. Part of this intercontinental gene flow is exacerbated by the production of Phalaris forage seed in Minnesota. The implications of these findings for management of invasive crops native to both continents are significant for forage producers, managers, and breeders.
Part of the book: New Perspectives in Forage Crops