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Abstract Detail



Systematics Section/ASPT

Molgo, Iwan [1], Soltis, Pamela [2], Soltis, Douglas [3].

Elucidating the polyploid complexes within Callisia Loefl. section Cuthbertia (Commelinaceae).

Callisia graminea, C. rosea and C. ornata are closely related species endemic to the southeastern United States, ranging from southeastern Virginia to south Florida. Polyploidy in C. graminea was discovered 70 years ago, and the evolutionary relationships among the three ploidal levels (2x, 4x and 6x) are still unclear. The diploid and tetraploid entities are geographically isolated and distinct in morphology and cytology. The origin of tetraploid C. graminea is uncertain; it may be an autopolyploid of diploid C. graminea or an allopolyploid derived from hexaploid C. graminea and diploid C. rosea. Hexaploid C. graminea is restricted to Florida and South Carolina; either C. rosea or C. ornata could be a parent, with the other likely parent being tetraploid C. graminea. I have located and sampled the cytotypes, and updated distribution maps have been compiled. The nuclear internal transcribed spacer (nrITS) region and plastid trnL trnF intron and intergenic spacer, the trnH-psbA spacer, and atpB - rbcL intergenic spacer have been explored for utility. The DNA sequences were tested for variation among samples of the three Callisia species and their putative polyploid derivatives. The nrITS region is polymorphic in two South Carolina tetraploid entities and in one Florida tetraploid entity suggesting alloploidy. All other tetraploids in Florida showed a single ITS copy. A combined analysis of the plastid data supports the monophyly of Callisia section Cuthbertia. Plastid data revealed variation among the tetraploid entities of C. graminea. The hexaploids were placed as sister taxa to diploid C. ornata and tetraploid C. graminea and are possibly a result of a hybridization event between C. ornata and tetraploid C. graminea. Sequencing of additional nuclear and plastid regions is being explored to further clarify relationships. This project is the first part of a larger study in which I will investigate gene flow and population structure in Callisia section Cuthbertia and examine the phylogenetic relationships of Callisia species across the entire genus.

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1 - University of Florida, Department of Biology, 385 Dickinson Hall, P.O. Box 117800, Gainesville, FL, 32611-7800, USA
2 - University of Florida, Florida Museum of Natural History, PO BOX 117800, Gainesville, FL, 32611-7800, USA
3 - University of Florida, Biology and Florida Museum of Natural History, Gainesville, FL, 32605, USA

Keywords:
Polyploidy
Southeastern United States
Endemics
Commelinaceae
Roseling
Callisia.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PSY072
Abstract ID:843
Candidate for Awards:None


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