Abstract Detail

Pteridological Section/AFS

Duffy , Aaron M [1], Farrar, Donald R [2], WOLF , PAUL G [3].

Exploring the population genetics of independent gametophytes of Crepidomanes intricatum (Farrar) Ebihara & Weakley (Hymenophyllaceae) using genotyping-by-sequencing.

Crepidomanes intricatum (Farrar) Ebihara & Weakley (Hymenophyllaceae) is a filmy fern found as gametophyte-only populations throughout the Appalachian Mountains in eastern North America. No sporophytes have been found or produced under a variety of growing conditions, suggesting this species is not capable of sexual reproduction and reproduces only through asexual gemmae.  The lack of obvious means of long-distance dispersal, evidence of limited short-distance dispersal, and presence of populations in previously glaciated areas raise questions about how and when these populations were founded and reached their current distribution.  Several hypotheses have been proposed, including recent or current dispersal of spores from unidentified sporophytes within their known range or from elsewhere, ancient introduction as spores with only asexual reproduction after introduction (they never existed as sporophytes in eastern North America), and ancient introduction as spores with subsequent sexual reproduction (sporophytes in North America) followed by extinction of the sporophytes.  To distinguish among these hypotheses requires knowledge of the relationships among these widespread populations.  Previous attempts to identify variable markers using allozymes and chloroplast DNA failed, but new methods for genotyping-by-sequencing allow for the identification of thousands of single nucleotide polymorphisms (SNPs) with no prior knowledge of the genome or the level of species diversity, even in species with large genomes.  Here, we use a method that reduces genome complexity and targets lower copy genomic regions through the use of methylation-sensitive restriction enzymes.  We use SNP data from 54 individuals to explore the variation within and among 30 populations sampled from throughout the known range of this species and we discuss what this variation suggests about its population establishment, gene flow, and evolutionary potential.

1 - Utah State University, Department Of Biology, 5305 Old Main Hill, Logan, UT, 84322, USA
2 - Iowa State University, Biology Dept, 353 Bessey Hall, Ames, IA, 50011, USA
3 - Utah State University, Ecology Center and Department of Biology, Logan, UT, 84322, USA

Keywords:
Genotyping by Sequencing
population genetics
independent gametophytes
filmy fern.

Presentation Type: Oral Paper:Papers for Sections
Session: 7
Location: Pines North/Boise Centre
Date: Monday, July 28th, 2014
Time: 11:15 AM
Number: 7011
Abstract ID:583
Candidate for Awards:Edgar T. Wherry award