Phylogeographic analysis points toward invasion of the Timanfaya National Park (Lanzarote; Canary Islands) by a translocated native plant ( Rumex lunaria )

Rumex lunaria is an endemic shrub of the Canary Islands, which is colonizing the Timanfaya National Park (TNP) in Lanzarote. Whether the arrival of R. lunaria to Lanzarote has been natural or by human intervention is still a matter of debate. To address this question, 100 specimens of R. lunaria were collected from the seven main Canary Islands, and genetic analysis of four chloroplast DNA loci were performed, covering a total length of 4809 nucleotide positions. Multiple alignments revealed 49 nucleotide substitutions, which define 30 different haplotypes. Island-specific haplotypes were found in Tenerife, La Gomera, La Palma and Gran Canaria, with the greatest diversity found in the first island. Interestingly, the unique haplotype detected in El Hierro is shared with almost all plants from Lanzarote (95%), including all individuals sampled in the TNP. The most frequent haplotype present in Gran Canaria was detected in only one sample from Lanzarote (5%). These results were corroborated by a robust phylogenetic analysis, which supports the hypothesis of a common origin of R. lunaria populations from El Hierro and the vast majority of those from Lanzarote. In addition, this study rules out the genetic singularity of the R. lunaria specimens that are colonizing the TNP.