Systematics Section / ASPT
Hall, Jocelyn , Donohue, Kathleen , Wheeler, Andrew , Gomez-Campo, Cesar , Kramer, Elena M .
Phylogenetics and fruit evolution of the tribe Brassiceae (Brassicaceae).
Although fruit morphology of Brassicaceae has long been considered an important diagnostic feature in assigning relationships within the family, recent molecular data indicate that fruit type and morphology is homoplasious in almost all fruit characteristics (within the Brassicaceae). The tribe Brassiceae is a natural group whose members display a wide range of fruit morphologies and many taxa have an unusual feature of having a lateral abscission zone that leads to the independent dispersal of distal and proximal segments. Heterocarpy is only found in the tribe Brassiceae, although the number of times this condition has evolved within the tribe is unresolved. Of particular interest is the genus Cakile whose relationship with two genera, Didesmus and Erucaria, is unresolved, and for which there have been previous evolutionary and ecological studies on fruit dispersal. The goal of this study is to address phylogenetic relationships within Brassiceae, with emphasis on the Cakile clade, by using evidence from DNA sequences of phytochrome A. We sampled broadly across previously identified lineages of Brassiceae and extensively among Cakile and relatives. The phylogeny is used to evaluate fruit character evolution focusing on heterocarpy and dehiscence.
1 - Harvard Univerisity, Organismic and Evolutionary Biology, 16 Divinity Ave, Biolabs 1109, Cambridge, Massachusetts, 02138, USA
2 - Harvard University, Organismic and Evolutionary Biology, 26 Oxford St., Cambridge, Massachusetts, 02138, USA
3 - Escuela T.S. Ing. Agronomos, Biologia Vegetal, Universidad Politecnica, 28040-Madr, Spain
Presentation Type: Paper
Location: Cottonwood A (Snowbird Center)
Date: Tuesday, August 3rd, 2004
Time: 4:45 PM