Abstract Detail

Systematics Section

Ferguson, Carolyn J. [1], Melhem, Theresa [1], Prather, L. Alan [2], Fehlberg, Shannon D. [3].

Perplexing patterns of polyploidy: investigating ploidy level variation and its correlates within the context of phylogeny in Phlox (Polemoniaceae).

Phlox is a genus of about 65 species exhibiting interesting diversity throughout much of North America. The genus is noteworthy for polyploidy (both allo- and autopolyploidy), which has likely contributed to complicated patterns of phylogeny for the group. A phylogenetic overview of the genus is presented, based on comprehensive taxonomic sampling for ITS and several cpDNA regions, as well as smaller data sets for several low copy nuclear regions. While some patterns are consistent among phylogenies, there is significant incongruence between data sets with respect to several large species complexes. Within this context, findings on ploidy level (based primarily on flow cytometry data) are presented for most samples. Removal of polyploid samples from phylogenetic data sets simplifies relationships, but some conflict remains. Interestingly, infraspecific variation in ploidy level (cytotype variation) is supported for numerous recognized Phlox taxa, including both wide-ranging, variable species (e.g., P. glaberrima, P. longifolia, P. pilosa) as well as some narrow endemic species (e.g., P. amabilis, P. woodhousei). We highlight several such examples of polyploid assemblages, discuss some complementary findings from population genetic study, and present preliminary morphological data relative to ploidy level patterns. Ongoing work employs multiple approaches (phylogenetic, population genetic and morphological) to rigorously examine species delimitation within key Phlox polyploid assemblages.

Broader Impacts:

1 - Kansas State University, Herbarium and Division of Biology, Ackert Hall, Manhattan, Kansas, 66506-4901, USA
2 - Michigan State University, Department of Plant Biology, Herbarium, 166 Plant Biology Wilson Road, East Lansing, Michigan, 48824-1312, USA
3 - Desert Botanical Garden, Research, 1201 N. Galvin Pkwy., Phoenix, AZ, 85008, USA

Keywords:
flow cytometry
incongruence
Phlox
phylogeny
Polemoniaceae
polyploidy.

Presentation Type: Oral Paper:Papers for Sections
Session: 38
Location: 555A/Convention Center
Date: Tuesday, August 3rd, 2010
Time: 1:45 PM
Number: 38004
Abstract ID:727