GENETIC-VARIATION BETWEEN SEVERAL SPECIES OF SECTIONS EXTRANERVOSAE, CAULORRHIZAE, HETERANTHAE, AND TRISEMINATAE (GENUS ARACHIS) ESTIMATED BY DNA POLYMORPHISM

Genetic variation within and among accessions of the genus Arachis rep resenting sections Extranervosae, Caulorrhizae, Heteranthae, and Trise minatae was evaluated using RFLP and RAPD markers. RAPD markers reveal ed a higher level of genetic diversity than did RFLP markers, both wit hin and among the species evaluated. Phenograms based on various band- matching algorithms revealed three major clusters of similarity among the sections evaluated. The first group included the species from sect ion Extranervosae, the second group consisted of sections Triseminatae , Caulorrhizae, and Heteranthae, and the third group consisted of one accession of Arachis hypogaea, which had been included as a representa tive of section Arachis. The phenograms obtained from the RAPD and RFL P data were similar but not identical. Arachis pietrarellii, assayed o nly by RAPD, showed a high degree of genetic similarity with Arachis v illosulicarpa. This observation supported the hypothesis that these tw o species are closely related. II was also shown that accession V 7786 , previously considered to be Arachis sp. aff. pietrarellii, and assay ed using both RFLPs and RAPDs, was possibly a new species from section Extranervosae, but very distinct from A. pietrarellii.