Systematics Section / ASPT
Stone, Robert Douglas , Andreasen, Katarina .
Testing for reticulate evolution and polyploid origins in Sidalcea (Malvaceae) using nuclear RPA2 and RPB2 gene sequences.
SIDALCEA is a west North American (mainly Californian) group with about 25 species. Some members are polyploids based on x = 10, but artificial crosses are always fertile (even among plants at different ploidy levels). Species delimitation is often difficult, with hybridization or recent divergence suggested as possible causes. The current study seeks to determine if exon and intron sequences from two low-copy nuclear genes, RPA2 and RPB2, are useful for reconstructing the evolutionary history in Sidalcea. We especially wanted to see if these biparentally inherited markers can provide any evidence for homoploid or allopolyploid hybrid speciation. Results indicate that there was an early duplication of both genes, perhaps coincident with a polyploid event preceding the divergence of Sidalcea and its putative sister lineage, Eremalche. This ancestral duplication was followed by loss of one locus or the other in some descendant lineages.
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Katarina Andreasens home page
1 - Uppsala University, Systematic Botany, Department of Evolution, Genomics and Systematics, Norbyvägen 18 D, Uppsala, SE-752 36, Sweden
Presentation Type: Oral Paper:Papers for Sections
Location: 144/Performing Arts Center
Date: Monday, July 31st, 2006
Time: 4:00 PM