Determining the origin of Phragmites australis in South Africa based on chloroplast DNA

Determining the origin of Phragmites australis in South Africa based on chloroplast DNA
Kim Canavan and Iain Paterson
Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa

The common reed, Phragmites australis (Cav.) Trin. ex Steud. is a perennial reed-like cosmopolitan grass that is one of the most widely distributed angiosperms in the world. In South Africa, P. australis is considered an indigenous plant, having a long history of utilisation in the country. However, in recent years expansion of P. australis range and abundance has suggested the possibility of a cryptic invasion by a non-native strain. This study determined the origin of P. australis in South Africa based on genetic analyses of haplotypes. Two non-coding regions in the chloroplastic DNA were sequenced from samples collected across the reed’s range in South Africa. Sequences were compared to Saltonstall (2002) worldwide haplotypes, which included the invasive haplotype ‘M’ that was found to be invading parts of the U.S.A. Results suggest that there has not been an introduction of an invasive haplotype, more specifically haplotype ‘M’, and that P. australis stands in South Africa are a unique, possibly African haplotype.