| Abstract Detail
Systematics Section / ASPT Mason-Gamer, Roberta [1]. The Elymus repens (Poaceae: Triticeae) genome combines
allohexaploidy with introgression. Elymus repens is commonly assumed to include two diploid genome sets from Pseudoroegneria (genome designation St) and one from Hordeum (H), resulting in a hexaploid genome complement of StStStStHH. Recently, data from a single copy nuclear starch synthase gene confirmed the presence of Pseudoroegneria and Hordeum genomes, while also revealing three additional, phylogenetically distinct, gene copies. The present study further dissects the origin of E. repens using DNA sequences from the nuclear genes encoding β-amylase and phosphoenolpyruvate carboxylase. Each of the three nuclear gene trees includes an E. repens + Hordeum clade, an E. repens + Pseudoroegneria clade, and one group of E. repens sequences unassociated with any of the sampled diploids and thus representing an unknown donor. The additional starch synthase gene copies seen in the original study (one nearly identical to sequences from Taeniatherum and the other apparently derived from a Pooid clade outside of the Triticeae) are hypothesized to have been acquired through introgression into an allohexaploid background comprising Pseudoroegneria, Hordeum, and unknown-donor genomes. On all three gene trees, the Hordeum-like sequences of E. repens are polyphyletic within the Hordeum clade, suggesting multiple contributions from Hordeum to E. repens, either at its origin, or through subsequent hybridization and introgression.
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1 - University of Illinois Chicago, Department of Biological Sciences, M/C 066, 845 W Taylor Street, Chicago, Illinois, 60607, USA
Keywords:
Poaceae
Triticeae
polyploidy
introgression
Elymus.
Presentation Type: Oral Paper:Papers for Sections
Session: CP23
Location: Continental A/Hilton
Date: Tuesday, July 10th, 2007
Time: 9:00 AM
Number: CP23005
Abstract ID:785 |
