MOLECULAR PHYLOGENY AND PHYLOGEOGRAPHY OF LUPINUS (LEGUMINOSAE) INFERRED FROM NUCLEOTIDE-SEQUENCES OF THE RBCL GENE AND ITS 1+2 REGIONS OF RDNA

Total DNA was extracted from 55 species of the Leguminosae (including 29 species of Lupinus). The chloroplast gene rbcL and the ITS 1 + 2 re gions of nuclear RNA genes were amplified by polymerase chain reaction (PCR) and sequenced directly. The sequences obtained were evaluated w ith character state (Maximum Parsimony) and distance methods (Neighbou r Joining). Phylogenetic trees obtained with both data sets and method s are mostly congruent. Genisteae and Crotalarieae are sister groups a nd share ancestry with the Thermopsideae/Podalyrieae. The genus Lupinu s, which forms a monophyletic clade within the Genisteae, shows a dist inct Old-New World disjunction and appears to be divided into several more or less distinct groups: (1) The species from the eastern part of South America. (2) The homogeneous rough-seeded group (Scabrispermae) of the Old World species which is well distinguished from the smooth- seeded group (Malacospermae). (3) Within the rather heterogeneous smoo th-seeded lupins a smaller subgroup with L. augustifolius, L. hispanic us and L. luteus is recognized. (4) Also separated are North American lupins and South American species with a western distribution. Genetic distances imply that the genus Lupinus evolved during the last 12-14 million years; ruling out the hypothesis that the present Old-New Worl d disjunction can be interpreted as a result of the continental drift. The genetic data suggest an origin in the Old World and an independen t colonisation of the Eastern parts of South America as opposed to Nor th America and the Western parts of South America.