Systematics Section / ASPT
Laureto, Pamela J. , Barkman, Todd J. .
Analyses of four chloroplast DNA intergenic spacers reveal a maternal parent of the rare allopolyploid – Solidago houghtonii (Asteraceae).
Solidago houghtonii(Asteraceae) is a federally threatened plant species endemic to shoreline habitats of the northern Great Lakes, with two disjunct inland populations. Morphology and polyploidy suggest this species of a hybrid origin. Several combinations of progenitor species have been suggested but none have been tested, and it is unclear whether the species is comprised of more than one entity. To begin dissecting the origin of S. houghtonii we assessed intra- and interspecific sequence variation at four noncoding chloroplast DNA loci (psbA -
trnH, trnL - trnF, rps16 - trnH, and accD - psaI), and the nuclear ribosomal DNA ITS region, in S. houghtonii and 20 other species of Solidago. Three polymorphic nucleotide positions were
found in the ITS sequences of S. houghtonii, consistent with the hypothesis of an allopolyploid origin. Analyses of chloroplast DNA from all accessions of S.
houghtonii showed that the species is monophyletic and may have had a single origin. Interestingly, analysis of the combined cpDNA sequence data revealed the presence of several small indels that are uniquely shared between S. houghtonii and S. gigantea. This pattern of shared indels may indicate S. gigantea is one of
the parents of S. houghtonii. This result is completely unexpected because S. gigantea is a member of section Solidago subsection Triplinervae and shares few morphological similarities with S.
houghtonii, a member of section Ptarmicoidei.
Log in to add this item to your schedule
1 - 365 Rosewood SE, E Grand Rapids, Michigan, 49506, USA
2 - Western Michigan University, Department of Biological Sciences, 3437 Wood Hall, Kalamazoo, Michigan, 49008, USA
Presentation Type: Array
Date: Wednesday, August 17th, 2005
Time: 9:45 AM