Abstract Detail

Systematics Section

Nelson, Gretchen [1], Burgess, Michael [1], Cushman, Kevin [2], Doucette, Eric [3], Campbell, Christopher [3].

Morphological and phylogenetic relationships of an unusual species, Amelanchier bartramiana (Rosaceae).

Amelanchier bartramiana (Tausch) M. Roemer is the most distinctive species of this genus in eastern North America. Its few-flowered inflorescences, imbricate leaf arrangement in bud, tapering ovary summit, and capacity to grow in alpine habitats are unique to this species in eastern North America. Diploid A. bartramiana carries two variants of the LEAFY gene that are far more divergent from one another than different variants of this gene are with any other diploid species in the genus. The relationships of these presumed gene copies to sequences of this gene in other diploid species are striking. One copy occurs in the eastern North American diploids A. arborea (Michx. f.) Fern., A. canadensis (L.) Medik., and A. laevis Wiegand that comprise what we call calde T and in all Old World diploids. The other copy found in A. bartramiana is also present in another eastern North American diploid, A. humilis Wiegand, and all western North American diploids. Our sampling of A. bartramiana has uncovered diploids at high elevation from Maine to West Virginia and polyploids at lower elevations from New England to the Great Lakes. These two groups differ more or less markedly in petiole length, petal size, and leaf shape. Sequences from the ETS region from A. bartramiana tetraploids either nest within a clade comprised only of A. bartramiana diploid individuals or are weakly supported as sister to the strongly supported clade that contains A. bartramiana plus clade T. This topological pattern is consistent with allopolyploidy, with diploid A. bartramiana as one parent. The other parent was most likely A. humilis, the range of which overlaps a large part of the range of A. bartramiana. One triploid A. bartramiana plant is apparently the only autopolyploid among scores of polyploids that we have studied in the genus.

Broader Impacts:

1 - University of Pennsylvaia, The Morris Arboretum, 100 E. Northwestern Avenue, Philadelphia, PA, 19118
2 - P.O. Box 143, Levant, ME, 04456, USA
3 - University Of Maine, Department Of Biological Sciences, 261 HITCHNER HALL, ORONO, ME, 04469-5735, USA

Keywords:
diploidy
allopolyploidy
autopolyploidy
hybridization.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM
Number: PSY019
Abstract ID:492