XVI International Botanical Congess

The floral structure of Lacandonia schismatica (Triuridales), is unique among all wild type and mutant phenotypes. Lacandonia's carpels surround three central stamens. We study the molecular basis and evolution of this phenotype. Models in Arabidopsis thaliana and Anthirrinum majus allow a hypothesis for the homeotic phenotype of Lacandonia: in the lineage leading to Lacandonia, the B genes (APETALA3 and PISTILLATA) shifted their expression toward the central whorl of the flower. We have cloned the MADS-box ABC orthologues from Lacandonia and present in situ hybridization data. We also present data on a DNA-based phylogeny for L. schismatica and relatives and map floral traits onto a phylogeny.