MATK AND RBCL GENE SEQUENCE DATA INDICATE THAT SAXIFRAGA (SAXIFRAGACEAE) IS POLYPHYLETIC

摘要: The large genus Saxifraga, which consists of z400 morphologically and cytologically diverse species, has long been considered taxonomically complex. Phylogenetic analysis over 2 500 bp chloroplast sequence data derived from matK rbcL was employed to examine relationships among sections the segregate genera Zahlbrucknera, Saxifragopsis, Cascadia, these taxa other Saxifragaceae sensu stricto. trees resulting separate analyses sequences were highly congruent; phylogenetic a combined matKrbcL matrix therefore also conducted. Our indicate that Saxifraga is polyphyletic, comprising two welldifferentiated clades. One clade, stricto, sister remainder family Irregulares, Heterisia, Trachyphyllum, Cymbalaria, Mesogyne, Xanthizoon, Porphyrion, Ciliatae, Cotylea, Ligulatae, Gymnopera. With exception Gymnopera, species-rich this clade are monophyletic. Also part problematic Zahlbrucknera paradoxa, allied with members section Saxifraga. A second major Micranthes lato, comprises Micranthes, as well S. tolmiei Merkianae. This Heuchera, Darmera, Chrysosplenium-Peltoboykinia groups genera. Saxifragopsis only distantly related species instead Astilbe. monotypic Oresitrophe confirmed member Darmera group These results suggest floral features used define may simply be symplesiomorphic in well-separated lineages. Furthermore, enormous cytological diversity encompassed by likely represents independent instances extensive aneuploidy polyploidy Saxifragaceae.