Abstract Detail

Molecular Ecology

Kooyers, Nicholas [1], Albano, Lucas [2], Gaspard, Aurora [1], Innes, Simon [1], King, Nevada [1], Miles, Lindsay [2], Santagelo, James [2].

Rapid adaptation during invasions? Synthetizing observational, ecological, and genetic studies in Trifolium repens (white clover).

The extent that adaptation can facilitate the spread of introduced species and contribute to invasibility is controversial. Early invasion botanists assumed that adaptation following introduction was minimal because introduction events included few colonizers and a limited pool of genetic variation. However, an influx of studies have documented extensive genomic variation in introduced regions and suggest that adaptation may be widespread. One prominent example is the parallel formation of adaptive clines in introduced regions in the frequency of cyanogenesis, the ability to produce hydrogen cyanide after tissue damage, in the white clover (Trifolium repens). Such studies have changed the direction of the field from examining whether adaptation occurs to determining how quickly selection acts, how much of the genome is impacted, and what effect selection has on the rate and extent of geographic spread. Here we synthesize the preliminary results from several ongoing experiments using white clover as a model system to examine the role of adaptation during invasion. Using a combination of herbarium genetics and field resurvey experiments, we investigate how long cyanogenesis clines took to form following introduction to North America as well as how these clines have shifted in the native and introduced regions around the world. Next, we examine the scale of local adaptation using provenance studies at low and high latitudes planted with ~100 populations originating from both the native and introduced range. Finally, we examine the worldwide introduction history of white clover leveraging low coverage whole genome sequencing and population genomic analysis performed on populations spanning six continents. Our results suggest that adaptation at cyanogenesis loci occurs rapidly after introduction, but cyanogenesis clines are still gradually shifting to better match clines in the native range. Introduced populations are better adapted to their current range than native populations from similar environments. Genetic diversity in introduced regions is substantial and differs dramatically from the population structure in the native range. In sum, these patterns suggest that extensive admixture and selection occurred following introduction to create robust patterns of local adaptation in <300 years.

1 - Univerity Of Louisiana, Lafayette, Biology, 410 E. St. Mary Blvd. , Billeaud Hall, Rm 108, Lafayette, LA, 70503, United States
2 - University of Toronto, Mississauga, Biology, 3359 Mississauga Road, William G. Davis Building, Rm 3056, Mississauga, ON, Canada

Keywords:
Introduction
Selection
Population Genetics
genomics
herbarium
common garden.

Presentation Type: Oral Paper
Session: ME1, Molecular Ecology
Location: /
Date: Tuesday, July 20th, 2021
Time: 3:30 PM(EDT)
Number: ME1003
Abstract ID:180
Candidate for Awards:None