Abstract Detail

Population Genetics/Genomics

Pelosi, Jessie [1], Krieg, Christopher [2], Adelhelm, David [3], Jarnagin, Kerianne [4], Zeller, Zachary [4], Sessa, Emily [5].

Population structure and dynamic fluctuations of effective population size in a polyploid fern complex .

Polyploidy, or whole-genome duplication (WGD), is associated with nearly one-third of speciation events in ferns, yet relatively little is known about the population genetic consequences following these events. The successful establishment of a polyploid population following WGD, however, may be rare and heavily dependent on key genetic processes such as gene flow. While recently formed polyploid populations are expected to have low genetic diversity, multiple origins of polyploid taxa coupled with long-distance dispersal may greatly enhance a taxon’s probability of survival. In order to better understand these processes, we investigated the population genetic dynamics of an allopolyploid fern from western North America, Polystichum scopulinum, and its progenitors, P. imbricans and P. lemmonii. We developed 10 primer pairs targeting microsatellite loci recently designed from an available transcriptome of the congeneric Polystichum acrostichoides. We analyzed the genetic structure of 237 individuals from across the range of each species using the R package polysat, STRUCTURE for diploids, and a Bayesian clustering method specifically designed for allotetraploids implemented in InStruct. We also explored historical changes in effective population size in the diploid progenitors using the program migraine. Preliminary data suggest that while both diploid progenitors are genetically structured, the polyploid has little to no population stratification. Low levels of genetic differentiation within P. scopulinum suggest that there are high levels of gene flow between populations consistent with other taxa in this genus. While migraine currently does not handle polyploid data, we found that both P. imbricans and P. lemmonii have undergone very recent contractions in effective population size. Paired with environmental and trait data in a forthcoming study, these conclusions are an important step in understanding polyploid population genetics and the successful establishment of polyploid species. 

1 - University Of Florida, Biology, 220 Bartram Hall, Gainesville, FL, 32611, United States
2 - University of Wisconsin, Birge Hall, 430 Lincoln Drive, Madison , WI, 53706
3 - 8700 European Fan Palm Alley, 8700 European Fan Palm Alley, Winter Garden, FL, 34787, United States
4 - University Of Florida, Department of Biology, 220 Bartram Hall, Gainesville, FL, 32611, USA
5 - University Of Florida, Biology, Box 118525, 521A Bartram Hall, Gainesville, FL, 32611, United States

population structure
population genetics.

Presentation Type: Poster
Session: P, Population Genetics/Genomics Posters
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 5:00 PM Time and date to be determined
Number: PPG005
Abstract ID:429
Candidate for Awards:None

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