Systematics Section / ASPT
Mavrodiev, Evgeny V. , Gitzendanner, Matthew A. , Tate, Jennifer A. , Edwards, Christine E. , Soltis, Pamela S. , Soltis, Douglas E. .
Parentage and concerted evolution in Eurasian polyploids of the genus Tragopogon (Asteraceae).
Tragopogon L. (Lactuceae, Cichorioideae, Scorzonerinae) is an Old World genus of approximately 150 species that occurs across Eurasia with a center of distribution in the Mediterranean region, the Middle East, and eastern Europe. The chromosome number reported for most species of Tragopogon is 2n = 12. There are also several polyploids, the most well known of which are those reported by Ownbey (1950), who showed that two allotetraploid species of Tragopogon, T. mirus and T. miscellus, formed in North America in the 1900s following the introduction of three diploids from Europe. Using ITS and ETS data, we showed previously that concerted evolution has occurred, but not to completion, in these recent allopolyploids. At least ten species of Tragopogon native to Eurasia are polyploids (or include polyploid cytotypes): T. buphthalmoides (DC.) Boiss. (2n = 24, 36), T. castellanus Levier (2n = 24), T. coloratus C. A. Mey. (2n = 12, 24), T. cupani Guss.ex DC. (2n = 12, 24), T. gracilis D. Don (2n = 24), T. graminifolius DC. (2n = 12, 24, 36), T. pusillus Bieb. (2n = 12, 24), T. reticulatus Boiss. et Huet. (2n = 12, 24, 36, 56 – 58), T. latifolius Boiss. (2n = 12, 24), and T. tuberosus C. Koch (2n = 24). However, the parentage of these Eurasian polyploids is unknown. Using plastid, ITS, and ETS sequences, we propose putative parents for many of these Eurasian polyploids. In addition, concerted evolution has apparently occurred to varying degrees. In some polyploids, there is no trace of the ITS/ETS from the maternal diploid parent. In other instances, one diploid parent is not evident in the sequence chromatograms of the polyploid, but its contribution can be detected via the sequencing of numerous clones.
1 - University of Florida, Department of Natural History, Florida Museum of Natural History, P.O. Box 117800, Gainesville, Florida, 32611-7800, USA
2 - University of Florida, Department of Botany, 220 Bartram Hall, P.O. Box 118526, Gainesville, Florida, 32611-8526, USA
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM