Cohen, Jim , Davis, Jerrold I. .
Chloroplast DNA sampling for phylogeny reconstruction: Lessons from Lithospermum L. (Boraginaceae).
Over the past decade, systematists have expanded the number of chloroplast DNA (cpDNA) regions used to examine phylogenetic relationships. However, for any particular set of taxa, the appropriate number, combination, and specific cpDNA regions to incorporate are unknown prior to data analysis. In order to investigate these three aspects of experimental design, we conducted multiple manipulations of a data matrix consisting of sequences of 10 cpDNA regions for 67 taxa, including species of Lithospermum and related taxa of Boraginaceae. Through the iterative removal of each region, the stability of the phylogenetic structure supported by the 10-region matrix was investigated. In addition, we examined specific 5-region combinations, the impact of adding one region at a time, and resolution obtained from each individual region. In this case we demonstrate that the specific combination of concatenated regions is important. In general, concatenating relatively slowly evolving regions with fast-evolving regions provides a useful combination of characters for reconstructing the greatest number of nodes that do not conflict with those reconstructed with additional sequence data. The following regions are recommended for future phylogenetic studies of relationships within and among genera of Boraginaceae: the rpl16 intron, matK, psbA-trnH, and trnL-rpl32.
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1 - Cornell University, Department of Plant Biology, 412 Mann LIbrary, Tower Road, Ithaca, NY, 14853, USA
2 - Cornell University, L.H. Bailey Hortorium, Department of Plant Biology, Ithaca, New York, 14853, USA
Presentation Type: Oral Paper:Papers for Sections
Location: 552B/Convention Center
Date: Wednesday, August 4th, 2010
Time: 8:00 AM