Genetic variation among South Brazilian accessions of Lippia alba Mill. (Verbenaceae) detected by ISSR and RAPD markers

twenty-seven accessions of lippia alba mill. collected in rio grande do sul state, brazil, were analysed by issr and rapd markers to evaluate their genetic variability and relationships. six issr primers and four rapd primers generated 120 amplified fragments, most of which were polymorphics. the overall genetic variability among accessions was very high when compared with other plant species. the hierarchical analysis of molecular data (upgma) showed low relationship between accessions, and no grouping between accessions of the same chemotype. canonical functions allowed identifying some variables related with the chemical characteristics of the essential oils. both issr and rapd markers were efficient to address the genetic diversity of l. alba, and may contribute to the conservation and breeding of this increasingly important aromatic and medicinal species.