Genetic variation and phylogenetic relationships based on RAPD analysis in section Caulorrhizae, genus Arachis (Leguminosae)

Wild Arachis germplasm includes potential forage species, such as the rhizomatous Arachis glabrata and the stoloniferous A. pinto and A. repens. Commercial cultivars of A. pintoi have already been released in Australia and in several Latin American countries, and most of these cultivars were derived from a single accession of A. pintoi (GK 12787). Arachis repens is less productive as a forage plant than is A. pintoi. However, it can be crossed with A. pintoi, and thus has good potential as germplasm for the improvement of A. pintoi. Arachis repens is also used as an ornamental plant and ground cover. Many new accessions of these two stoloniferous species are now available, and they harbor significant genetic variability beyond that available in the few older accessions, previously available. Therefore, these new accessions need to be conserved, documented and considered in terms of their potential for crop improvement and direct commercial use. Sixty-four accessions of this new germplasm were analyzed using RAPD analysis. Most of the accessions of A. repens grouped together into a clearly distinct group. In general, the accessions from the distinct valleys of the Jequitinhonha, São Francisco and Paranã rivers did not group together, suggesting there is not a tight relation between dispersion by rivers and the geographic distribution of genetic variation in these species.