DNA polymorphisms reveal geographic races of reed canarygrass
Reed canarygrass (Phalaris arundinacea L.) is a cool-season perennial with a circumglobal distribution in the northern hemisphere, native to Europe, Asia, and North America. Repeated introductions of European germplasm into North America have created confusion over the origins of reed canarygrass germplasm found in wetlands, pastures, and breeding programs. The objectives of this study were to identify sources of DNA marker variation among reed canarygrass cultivars from Europe and North America and between landraces and improved cultivars from North America. Analysis of 205 reed canarygrass plants from 15 cultivars based on 102 amplified fragment length polymorphic (AFLP) DNA markers revealed two groups of cultivars. One group consisted of three closely related but geographically diverse North American landraces that were completely separated from all other plants in only two dimensions of the AFLP incidence matrix. The complete discrimination of these plants from all European plants suggests their possible origin from native North American germplasm. These results were supported by chloroplast DNA sequence analysis, which additionally revealed separation of a potential Scandinavian cytoplasmic race from the continental European cytoplasmic race. This is the strongest evidence to date suggesting that native North American reed canarygrass germplasm has been preserved within cultivars of this species.