Abstract Detail

Population Genetics/Genomics

Hasenstab-Lehman, Kristen [1], Guilliams, C. Matt [1].

Conservation Genetics of Dithyrea maritima (Davidson) Davidson (Brassicaceae), beach spectaclepod.

Dithyrea maritima (Davidson) Davidson (Brassicaceae), or beach spectaclepod, is a dune specialist endemic to coastal dunes from central California, United States, tonorthwestern Baja California, Mexico. A perennial herb, individuals spread by rhizomes, forming a diffuse colony of ramets, each terminating in rosette of 1 to several fleshy leaves. Vegetative ramets appear mid-winter to mid-spring months. Flowering typically occurs from April to July, with the apex of the ramet elongating to form a dense raceme or cluster of fragrant flowers. Corollas are white, cream, or sometimes pink to purple tinged. As the common name alludes, the species produces a two-chambered fruit (silicle) that resembles spectacles; each round half of the fruit contains a single seed. It is listed on the California Native Plant Society Rare and Endangered Plant Inventory on list 1B.1 and was listed as Threatened under the California Endangered Species Act. Threats to extantoccurrences include OHV activity, marine mammal activity, and non-native plants; it is also among the most threatened of coastal California plants with respect to climate change.Perhaps owing to these threats or some aspect of its life history, studied occurrences of the self-incompatible D. maritima have low seed set in general despite having seemingly adequate pollinator service in some (but not all) locations. Previous studies have shown that manual outcrosses boost seed production substantially, however, suggesting that knowledge of the distribution of genotypes on the landscape could be a critical first step toward any number of recovery actions. In this study, we sample from approximately 30 individuals from each of 9 sampling locations spanning the range of the taxon from Morro Bay, CA, USA to San Quintín, Baja CA, MX. We used double digestion RADsequencing and high-throughput to generate loci across genome. We used the ipyrad and Stacks pipelines to assemble our SNP datasets, and analyze population structure of the species. Here we make a first report on our findings, placing the observed population genomic patterns into the context of regional biogeography. We conclude with recommendations for managing the species given the on-going threats of climate change and lack of seed set.

1 - Santa Barbara Botanic Garden, Department of Conservation and Research, 1212 Mission Canyon Road, Santa Barbara, CA, 93105, USA

Keywords:
Conservation
population genomics.

Presentation Type: Oral Paper
Session: 47, Population Genetics and Genomics II
Location: 101/Mayo Civic Center
Date: Wednesday, July 25th, 2018
Time: 4:30 PM
Number: 47012
Abstract ID:864
Candidate for Awards:None