Abstract Detail

Molecular Ecology

Van Etten , Megan [1], Baucom, Regina [2].

Genome-wide search uncovers evidence for convergent and divergent responses to selection in a weedy species.

The evolution of herbicide resistance is often given as an example of extreme parallelism, with different species using the same genetic change to adapt to herbicide use. However, these results are biased by studies that focus on the herbicide's target gene, rather than more agnostic, genome-wide searches. Here, we used a population genomics approach and exome re-sequencing to identify genes involved in herbicide resistance across several resistant populations of the weed Ipomoea purpurea. We found 5 genomic regions that show evidence of selection. Within these regions, genes involved in herbicide detoxification--cytochrome P450s, ABC transporters, and glycosyltransferases--are enriched and exhibit signs of selective sweeps. Interestingly, the pattern of variation was population specific in some regions under selection whereas other regions of the genome showed the same pattern among resistant populations. This suggests that there are both convergent and divergent responses involved in the evolution of herbicide resistance in this species. More broadly, this suggests that genome-wide approaches may change our understanding of the occurrence of convergent evolution at the genomic level.

1 - Penn State, Penn State Worthington Scranton, 120 Ridge View Dr, Dunmore, Pennsylvania, 18512, United States
2 - University of Michigan, 830 N University Ave, Ann Arbor, MI, 48109, United States

Keywords:
Adaptation
herbicide
exome resequencing
convergent evolution.

Presentation Type: Oral Paper
Session: 22, Molecular Ecology
Location: 107/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 9:00 AM
Number: 22004
Abstract ID:662
Candidate for Awards:None