Systematics Section / ASPT
McKain, Michael R. , Ingram, Amanda .
Confirmation of hybrid origin of Eupatorium x truncatum using DNA sequence data.
An excellent model for studying plant hybrid speciation is Eupatorium L. (Asteraceae), a genus of approximately 1000 species native to temperate eastern North America, Europe, and eastern Asia with multiple known cases of speciation through hybridization. Two species that are thought to hybridize in the genus Eupatorium are E. serotinum Michx. and E. perfoliatum L. Their putative hybrid, E. x truncatum, was first documented from a single individual found near Hanover, Indiana in 1938 and was named E. serotinum var. polyneuron (F. J. Herm.). The individual was first thought to be a variety of E. serotinum based on their morphological similarities. In 1989 Arthur Tucker noted that the morphological features of E. serotinum var. polyneuron were a novel combination of characteristics of both E. serotinum and E. perfoliatum and gave it hybrid status as E. x truncatum. In this study, analysis of sequence data from the plastid psbA-trnH intergenic spacer and the internal transcribed spacer region (ITS) of nuclear ribosomal DNA was used to assess the relationship between E. x truncatum and its possible progenitors, E. serotinum and E. perfoliatum. The nuclear data support the proposed relationship between the hybrid and its progenitors, and the plastid sequences indicate that in this population E. serotinum is the maternal progenitor of all individuals sampled.
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1 - Wabash College, Department of Biology, PO Box 352, Crawfordsville, IN, 47933, USA
Presentation Type: Poster:Posters for Sections
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM