Plant & Animal Genomes XV Conference Plant & Animal Genomes XV ConferenceJanuary 13-17, 2007
Town & Country Convention Center
San Diego, CA
One of every 10 flowering plant species is in the Compositae; the family is monophyletic. There is a great deal of morphological diversity among its taxa but nearly all species are easily recognizable as members of this family. The core tribes recognized by Cassini and Bentham are mostly monophyletic but, as a result of molecular studies, the relationships among them have changed and new tribes and subfamilies have been identified. Recent molecular studies were used to produce a meta-supertree formed by the grafting of the tribal trees onto a base supermatrix tree. Examination of the distribution of terminal taxa indicates that the origin of extant members of the Compositae was in southern South America with a subsequent radiation in Africa which gave rise to most extant tribes. The African radiation contains clades from Asia, Eurasia and Australia. There was a North American origin and diversification of the Heliantheae s. l. This global picture provides a framework for studies in morphology, evolution, and diversification. For instance, the evolution of the corolla types, secondary plant chemistry, styles, etc. are examined in light of the supertree. Problems include lack of resolution in areas of the base tree despite the use of 15,000 base pairs (chloroplast). Future work must involve the use of new areas of the genome and increased interactions with the genomic community.