PHYLOGENETIC-RELATIONSHIPS IN THE GENUS STYLOSANTHES (LEGUMINOSAE) BASED UPON CHLOROPLAST DNA VARIATION

A detailed analysis of chloroplast DNA restriction fragment length var iation was undertaken to reconstruct the maternal phylogeny of 18 taxa from both sections of the papilionoid tropical forage legume genus St ylosanthes. Data were analysed by means of the computer program PAUP, using an heuristic search with Wagner parsimony. The resulting cladogr am divided Stylosanthes into four separate clades, which comprised: (i ) the S. guianensis complex and related species (i.e. S. gracilis, S. grandifolia and S. mon tevidensis); (ii) S. hispida, tetraploid S. ham ata s. 1., S. sympodialis, S. humilis, S. leiocarpa, S. angustifolia a nd certain accesions of S. scabra; (iii) S. calcicola, S. viscosa, dip loid S. hamata s. str., and S. fruticosa, plus accessions of S. scabra , S. capitata and one accession of S. grandifolia; and (iv) S. macroce phala and other accessions of S. capitata not included within clade 3. Results are generally congruent with previously established interspec ific relationships and, moreover, enabled identification of putative m aternal progenitors for four tetraploid taxa: S. humilis was identifie d as a Likely maternal parent of both S. sympodialis and S. hamata s. 1., S. viscosa as a maternal parent of S. scabra, and S. macrocephala as a maternal parent of S. capitata.