Use of RAPD markers for the genetic characterization of Limonium species

The genus Limonium (fam. Plumbaginaceae) consists of about 300 species of mostly herbaceous perennials, some low shrubs, and annuals. Most botanical species are endemics in the Mediterranean region, but many species have their centre of origin in Caucaso, Turkestan, Caspian Sea, Russia, Iran, China, and South Africa. Limonium is grown in several regions of the world for use as a cut flower for both fresh and dry-flower arrangements. In this work, RAPD analyses were used for the study of genetic relationships in Limonium. Thirteen wild species were tested with 10 primers. A total of 244 bands were scored and used for the analysis of genetic distances. The dendrogram obtained from cluster analysis showed high similarity among three species that some authors report as synonymous and that appeared very similar from our previous phenotypic observations (L. caspia, L. bellidifolium and L. otolepis). In order to clarify the genetic relationships, further analyses were carried out on several genotypes belonging to these species. The new dendrogram, obtained scoring 151 RAPD bands, showed that the genotypes did not group in clear clusters. Analysis of molecular variance (AMOVA) confirmed this trend: the highest genetic variation resulted among genotypes and only 6,58% of the total variation resulted among the species. These results suggest that the species can be considered synonymous. The use of RAPD markers in our case was thus useful for clarifying the highly probable identity of the three Limonium species, in a plant genus that is notably of difficult interpretation.