Recent Topics Posters
Straub, Shannon C.K. , Pfeil, Bernard E. , Doyle, Jeff J. .
Testing the polyploid past of soybean using a low-copy nuclear geneľ is Glycine an auto- or allopolyploid?.
The papilionoid legume genus, Glycine Willd. of the tribe Phaseoleae, is thought to be of ancient polyploid origin, with the most recent genome duplication event occurring about 15 mya. To explore this hypothesis of polyploid origin and whether this event involved autopolyploidy or allopolyploidy, we selected a pair of paralogues of the gene encoding a putative protein (At1g73230) for molecular phylogenetic analysis. This gene was an appropriate tool to approach this question because its paralogues have been estimated to derive from the 15 mya genome duplication. We amplified paralogues from species of Glycine and two close generic relatives, Teramnus and Amphicarpaea. The results of our analysis show strong support for a sister group relationship between Glycine paralogues and favor an autopolyploid, rather than an allopolyploid, origin of the genus. This outcome parallels earlier results from paralogues of chloroplast-expressed glutamine synthetase (ncpGS). However, this gene provides little additional insight into the relationships between genome groups within Glycine due to low levels of differentiation among orthologues. Analysis of the putative protein (At1g73230) gene also shows possible evidence of another duplication of this gene following the polyploidy event, with retention of the additional copy in the annual subgenus Soja and loss of the additional copy in the perennial subgenus Glycine.
1 - Cornell University, L.H. Bailey Hortorium, Department of Plant Biology, Ithaca, New York, 14853, U.S.A.
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM