Abstract Detail

Population Genetics/Genomics

Edwards, Christine [1], Linan, Alexander [2], Swift, Joel [3].

Population genomic analysis clarifies the distinctiveness of taxonomically questionable subspecies of Lilaeopsis schaffneriana (Apiaceae).

Understanding the distinctiveness of taxonomically questionable, threatened or endangered species is important to ensure that conservation efforts are devoted to protecting truly unique taxa. One such species, Lilaeopsis schaffneriana subsp. recurva, is a federally endangered plant occupying freshwater streams in Arizona and adjacent areas in Sonora, Mexico (west of the continental divide). Both the morphology and the geographic range of this subspecies overlap with those of L. schaffneriana subsp. schaffneriana, a more widespread subspecies found in central/northern Mexico (east of continental divide) and Ecuador, suggesting that the two subspecies may not be distinct. The goal of this study was to test the genetic distinctiveness of the two subspecies of L. schaffneriana and whether subsp. recurva is unique and deserves protection. We used a 2B-RAD-seq approach to generate SNP data from populations of both subspecies and a closely related congener, reconstructed the phylogeny, and analyzed patterns of genetic structure. Phylogenies revealed that populations of L. schaffneriana subsp. schaffneriana in Ecuador are the sister group to a clade made up of North American populations of both subsp. recurva and subsp. schaffneriana. Consistent with these results, analyses of genetic structure revealed that the Ecuadorean populations of subsp. schaffneriana are as genetically distinct from the remainder of L. schaffneriana as the outgroup and likely represent an undescribed species. Contrary to expectations, both phylogenies and analyses of genetic structure revealed strongly supported genetic differentation between subsp. recurva and subsp. schaffneriana populations in North America. These results indicate that conservation efforts for subsp. recurva are warranted because they are protecting a unique subset of the genetic variation in Lilaeopsis schaffneriana.

1 - Missouri Botanical Garden, PO Box 299, St Louis, MO, 63166, United States
2 - Saint Louis University, 3507 Laclede Avenue, St. Louis, MO, 63103-2010, United States
3 - Saint Louis University, 2166 Lawrence St., APT 2N, St. Louis, MO, 63110, United States

Keywords:
RAD-seq
genetic structure
species delimitation
Apiaceae
aquatic plants
Endangered Species
conservation genomics
Lilaeopsis.

Presentation Type: Oral Paper
Session: 47, Population Genetics and Genomics II
Location: 101/Mayo Civic Center
Date: Wednesday, July 25th, 2018
Time: 3:45 PM
Number: 47009
Abstract ID:955
Candidate for Awards:None