Phylogenetic implications of chloroplast DNA variation in the Berberidaceae

In spite of extensive studies using chromosome number, floral anatomy, pollen morphology, and serology, substantial disagreement still remains in the systematics of the Berberidaceae. We employed two different molecular systematic approaches, gene sequencing and restriction site analysis, to test competing hypotheses about intergeneric relationships in the family. Both rbcL gene sequence and restriction site data are congruent in recognizing four major chromosomal groups (x = 10, 8, 7, and 5). Fragmentation of the Berberidaceae into smaller families, especially separation of Nandina as a distinct family was not supported. The large woody genera, Berberis and Mahonia, are related to the monotypic herbaceous genus, Ranzania. Bongardia is nested within the x = 6 clade, and has a remote relationship to the Leontice group with which the genus has been placed for long time in most previous classifications. Although there are some major incongruences, our molecular systematic studies support the morphological classification proposed by LOCONTE & ESTES (1989).