Abstract Detail

Systematics Section/ASPT

Janssen, Richard [1], Ballard Jr, Harvey [2].

Population variation and hybridization in an allodecaploid Viola species group: Microsatellites from 454 shotgun sequencing.

Newly developed genomics tools have allowed us to quantify more evolutionary data than ever before. This recent revolution in technique has given us specific regions of DNA that are useful for assessing variation and genetic distinctness in related organisms. Regarding microsatellite variation, non-model organisms usually require a large amount of time, money and effort to isolate microsatellite loci for genetic studies. Using microsatellites we can assess population genetic variation and also confirm (or refute) instances of apparent hybridization among species. We submitted a genomic extract of the widepspread woodland violet, Viola sororia, to shotgun genome sequencing and processed the reads through QDD software. Considering only dinucleotide repeats of at least 8 bp and tri- to heptanucleotide repeats of at least 5 bp as most likely to express population-level variation, we identified 598 potential microsatellites in V. sororia. Two members of the allodecaploid 'stemless blues', subsect. Boreali-Americanae, in Ohio, prairie birdsfoot violet (Viola pedatifida) and bog violet (Viola nephrophylla), are listed as state-endangered. We sampled populations of multiple species in intermingling mixed-species sites at Pearl King Savannah and Gallagher Fen, where both species have been reported to grow near or with V. sororia, V. sagittata and V. palmata plus potential hybrids. Our questions were how much population diversity is expressed in the two endangered species at the sites, and whether the morphological intermediates could be confirmed as hybrid plants. A series of microsatellites isolated from the shotgun sequencing were amplified in population samples of species and putative hybrids using designed primer pairs, and electrophoresed on high-resolution Metaphor agarose gels stained with ethidium bromide. Microsatellite loci typically showed high success of amplification and easy interpretability. Populations of the 'stemless blue' group expressed multi-locus variation, with species-specific patterns beginning to emerge. We could confirm hybrid origins for the various intermediate plants. Our results urge the use of microsatellite variation in populations and taxa of high polyploid groups like the 'stemless blue' violets as a feasible molecular marker approach, and also highlight the efficiency and affordability of isolating microsatellites using 454 shotgun sequencing in polyploid groups.

Broader Impacts:

1 - Ohio Universtiy, Environmental and Plant Biology, Athens , OH, 45701, USA
2 - Ohio University, Environmental & Plant Biology/Molecular & Cellular Bio Program, 315 Porter Hall, Athens, OH, 45701-2979, USA

Keywords:
Viola
Boreali-Americanae
microsatellite
Violaceae
hybridization.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PSY013
Abstract ID:392
Candidate for Awards:None