Systematics Section / ASPT
Drummond, Christopher .
Phylogeny of Lupinus (Fabaceae) based on non-coding chloroplast DNA.
Lupinus forms a large genus of 150+ species, primarily from North America, South America, and the Mediterranean region of Africa and Eurasia. Relationships in Lupinus have long been uncertain, partly due to labile and often subtle morphological differences between species, and may be further confounded by gene flow and incomplete lineage sorting among recently diverged taxa. Previous studies of Lupinus using nuclear ribosomal spacers (ITS1+2) and coding cpDNA (rbcL) have failed to provide substantial resolution within the genus. In order to establish a phylogenetic framework for testing hypotheses about the evolution of floral display phenotypes and mating systems, non-coding chloroplast sequence data were collected from two intergenic spacers (trnS-trnG, trnT-trnL) and an intron (trnL intron) to estimate the phylogeny of Lupinus. 70+ specimens were sampled from across the genus and five outgroup genera (Argyrolobium, Chamaecytisus, Genista, Laburnum, Spartium) in the Papilionoideae. Preliminary combined analyses of non-coding cpDNA provide strong support for relationships among multiple clades in a large assemblage of New World species, but yield less resolution among basal lineages of Lupinus. To examine fine-scale relationships in closely related taxa, nuclear microsatellite markers are being developed to estimate population structure and outcrossing rates in the ‘Platycarpos’ Lupinus with sessile cotyledons, a monophyletic and phenotypically diverse group of annual species that are widely distributed in western North America.
1 - Georgetown University, Department of Biology, 406 Reiss Sciences Bldg, 37th & O St NW, Washington, DC, 20057
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM