Poster: Genome evolution

Abs # 846: Searching for microsatellites in Viola

Presenter:	Beil, Scott , sb238202@ohio.edu
Authors	Beil, Scott  (A)   Cortes-Palomec, Aurea C. (A)   Ballard, Harvey E. (A)   Wyatt, Sarah E. (A)
Affiliations:	(A): Ohio University

The violet family (Violaceae) is a worldwide family of flowering plants consisting of 25 genera and 900 species. Within the family, the genus Viola is the largest with about 600 species. Viola is important both horticulturally (the cultivated Pansies) and ecologically as often ubiquitous understory herbs in temperate forests. Our understanding of the dynamics of natural populations is however not well known, having lacked a powerful tool for elucidating patterns of parentage and genetic relatedness. Microsatellites (intersequence sample repeats or SSR’s) are short sequence repeats of DNA (1-6 bp) in eukaryotic genomes. They are mostly non-coding sequences that appear to evolve rapidly due to weak selection pressures and high mutation rates associated with replication slippage. Microsatellite variation has proved important in studies of population genetics, hybridization, and identification of cultivars due to an ability to determine co-dominant genotypes. Therefore, microsatellites can help elucidate genetic relationships in Viola. To identify microsatellite loci in Viola a new, simplified approach was used. First, genomic DNA was fragmented by either a restriction enzyme approach or sonication. Adaptors were then ligated to the fragmented DNA, and potential microsatellite loci amplified by PCR using the SSR and adaptor sequences as primers. Products were ligated into plasmids and transformed into E. coli for sequencing. A variety of restriction enzymes, primers and changes in methodology were used to identify microsatellite loci in Viola. The identified microsatellite loci will be used to assess genetic variability in populations of different species of wild violets and cultivated pansies (Supported by a grant from the Ohio Plant Biotechnology Consortium).