Abstract Detail

Systematics Section/ASPT

Steele, Kelly [1], Nidey, Tyffany [2], Zilnik, Gabriel [3], Yoder, Jeremy [4], Tiffin, Peter [4], Mudge, Joann [5], Weiblen, George [6], Wojciechowski, Martin [7].

Phylogenetic analyses of Medicago using plastid and nuclear-encoded molecular markers and whole genome sequence data.

Phylogenetic analyses of the genus Medicago utilized three data sets: 1) a multi-locus molecular marker data set of both plastid and nuclear-encoded molecular sequences (plastid trnK/matK region, nuclear encoded GA3 oxidase gene, nrDNA ITS, and CNGC5) for most species within the genus, including multiple samples per species; 2) nrDNA ITS sequences from more than 200samples including multiple accessions of most species; and 3) whole genome sequence data from 29 taxa sampled throughout the genus aligned with the Medicago truncatula reference genome to identify approximately 87,596 variant sites. The first two data sets were analyzed with parsimony and Bayesian methods, while the third was analyzed with parsimony methods and subsets analyzed with a recently developed algorithm for bialleic data, SNAPP(SNP and AFLP Phylogenies). Variation in results obtained among markers and regions of whole genome data will be addressed. Nevertheless, there exists considerable congruence among results which are used to develop a robust phylogeny to explore hypotheses of chromosomal and morphological evolution within the genus. For example, results support the hypothesis that an n=8 species with a narrow distribution, e.g. M.noeana, is sister to three widely distributed species, M. constricta, M. rigidula, and M. rigiduloides, which are n=7, suggesting that in this clade aneuploid reduction is associated with diversification. A similar, although somewhat more complex situation exists for the clade that includes M.polymorpha and M. murex (both n=7) with M. heyniana as the n=8 narrowly distributed sister species. However, the ephemeral, geocarpic species M. hypogaea (also n=7) whose relationship has not been resolved by previous published analyses, is sister to a widely distributed group of n=8 species suggesting that aneuploid reduction is not always associated with diversification.

Broader Impacts:

1 - ARIZONA STATE UNIVERSITY POLYTECHNIC, DEPT. OF APPLIED BIOLOGICAL SCIENCES, EAST COLLEGE, 6073 S. Backus Mall, MESA, AZ, 85212, USA
2 - Arizona State University – Polytechnic campus, Applied Sciences and Mathematics, 6073 S. Backus Mall – MC 2580, Mesa, AZ, 85212, USA
3 - Arizona State University Tempe, School of Life Sciences, Tempe, AZ, 85287, USA
4 - University of Minnesota, Department of Plant Biology, St. Paul, MN, 55108, USA
5 - National Center for Genome Resources, Santa Fe, NM, 87505, USA
6 - University Of Minnesota, PLANT BIOLOGY, 250 Biological Sciences Center, 1445 Gortner Ave, St. Paul, MN, 55108, USA
7 - Arizona State University, PO Box 874501, Tempe, AZ, 85287-4501, USA

Keywords:
phylogenomics
aneuploid reduction.

Presentation Type: Oral Paper:Papers for Sections
Session: 18
Location: Franklin A/Hyatt
Date: Monday, July 9th, 2012
Time: 2:30 PM
Number: 18005
Abstract ID:1016