Systematics Section / ASPT
Sanchez, Adriana , Kron, Kathleen A. .
Phylogenetic relationships of Eriogonum and relatives using the second intron of LEAFY.
PHYLOGENETIC relationships within Polygonaceae have become clarified due to recent molecular studies using the chloroplast region rbcL and matK. The traditional subdivision in the subfamilies Eriogonoideae and Polygonoideae are not supported since the latter subfamily is paraphyletic and Eriogonoideae is nested within Coccoloboideae. However in these studies there was an emphasis on the genera comprising what has been described as Polygonoideae and only one genus of Eriogonoideae was represented. Eriogonoideae, as traditionally recognized, comprises approximately 20 genera, several of which are monotypic, and ca. 320 species. Eriogonum is the largest genus with around 250 species distributed in North America and Mexico, with high degree of endemicity in Western North America. Species of Eriogonum have been regarded as one of the most difficult to distinguish based on morphological characters and there is a lack of knowledge of their evolutionary relationships. In this study we explore the relationships among the genus Eriogonum and some related genera, Chorizanthe, Dedeckera and Johanneshowellia using the second intron of the nuclear homeotic gene LEAFY. The second intron comprises around 1400bp and the number of parsimony informative characters is around 15%. A region consisting of almost 400bp had to be excluded from phylogenetic analyses due to the difficulties in alignment. Results of parsimony analyses indicate that the genus Eriogonum is paraphyletic with Dedeckera, Chorizanthe and Johanneshowellia embedded with it. Subgeneric divisions previously proposed for Eriogonum are not supported. Some species of the same subgeneric division showed strong bootstrap support (e.g Eriogonum fusiforme and E. inflatum), but in general, the clades consist of species of several subgenera.
Log in to add this item to your schedule
1 - Wake Forest University, Department of Biology, PO Box 7325, 226 Winston Hall, Winston-Salem, North Carolina, 27109-7325, USA
Presentation Type: Oral Paper:Papers for Sections
Date: Monday, July 31st, 2006
Time: 11:30 AM