Systematics Section / ASPT
Morris, Julie A. , Graham, Shirley A. , Schwarzbach, Andrea E. .
A molecular phylogeny of the Lythraceae based on six gene regions: evidence for repeated convergent evolution of extreme variation in life history traits.
The Lythraceae (Myrtales) comprises approximately 32 genera and 600 species with a worldwide distribution. Members of the family show extreme variation in habit, ranging from tall trees and woody shrubs to small aquatic herbs. This vegetative variation, combined with a fairly generalized floral morphology, has made determining the relationships among these genera based on traditional morphological characters challenging. Previous molecular analyses have been unable to distinguish among various hypotheses of basal relationships within the family, making it difficult to correctly polarize characters for the study of morphological evolution. In this study, molecular data from two newly sequenced chloroplast regions (atpB-rbcL intergenic spacer and the trnK-matK region) are added to previous sequence data (rbcL, trnL-trnF, psaA-ycf3, and ITS) and analyzed using maximum parsimony and Bayesian approaches. Topologies resulting from these analyses are congruent and fairly well resolved, recognizing 5-6 major terminal clades. The relative relationships of these terminal clades are more stable than in previous analyses, however, statistical support for basal relationships remains relatively low, possibly suggesting an early rapid radiation among these taxa. It is clear that multiple convergences in morphological characters and life history traits have occurred during the evolution of this family.
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1 - Kent State University, Department of Biological Sciences, 256 Cunningham Hall, Kent, Ohio, 44242, USA
2 - Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri, 63166-0299, USA
3 - University of Texas, Biological Sciences, 80 Fort Brown
, Brownsville, Texas, 78520, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Stevens 3/Hilton
Date: Wednesday, July 11th, 2007
Time: 1:30 PM