XVI International Botanical Congess

Phylogenetic relationships across Rosaceae were inferred from cladistic analyses of DNA sequences of chloroplast matK genes and nuclear genes encoding polygalacturonase inhibitor proteins (PGIPs). Results were generally consistent with published results from rbcL data. In addition, the Spireaeoid genus Gillenia appeared as the sister taxon to Maloideae sensu lato. The results support the conclusions that sorbitol synthesis and nitrogen fixation each evolved once in the family, while some fruit types evolved several times. Multiple gains and/or losses of an intron in PGIP genes have occurred within Rosaceae. Several strongly supported clades were identified, but, in general, relationships among those clades were weakly resolved. This may reflect a rapid radiation of major lineages within the family and/or a complex history involving reticulation among those lineages.