Abstract Detail

Bryology and Lichenology

Allen, Jessica [1], McKenzie, Sean [2], Sleith, Robin [3], Alter, Elizabeth [4].

Population Genomics of the Rock Gnome Lichen (Cetradonia linearis) Characterized by Low Rates of Recombination and Strong Isolation by Distance.

Obligate symbioses are some of the most threatened organisms globally. Population genetics in obligate symbiotic organisms is challenging, often requiring axenic isolates to develop species-specific markers. The burgeoning field of population genomics provides tools to circumvent these traditional demands by allowing detailed investigation of symbiont population structure without isolating symbionts and developing species-specific markers. Here the results of a population genomics study based on whole genome shot gun sequencing of Cetradonia linearis, an endangered, lichenized fungus, are presented. These data were used to 1) assemble and annotate a reference genome, 2) characterize the mating system, 3) test for isolation by distance (IBD) and isolation by environment (IBE), and 4) investigate the biogeographic history of the species. Nineteen and a half Mb of the genome (approximately 70%) was assembled, and only the MAT 1-2-1 idiomorph was located, suggesting the species could be unisexual. There was strong evidence for both low rates of recombination and for IBD, but no evidence for IBE. The hypothesis that C. linearis had a larger range during the last glacial maximum, especially in the southern portion of its current extent, was supported by hindcast species distribution models and the spatial distribution of genetic diversity. Given the findings here, it is recommended that C. linearis continues to be protected by the U.S. Endangered Species Act and listed as Vulnerable on the International Union for the Conservation of Nature Red-List.

1 - The New York Botanical Garden, 2900 Southern Boulevard, Bronx, NY, 10458, USA
2 - Rockefeller University
3 - New York Botanical Garden, 2900 Southern Boulevard, Bronx, NY, 10458, USA
4 - York College

Keywords:
conservation
Fungal Reproduction
biogeography.

Presentation Type: Oral Paper
Session: 28, Bryology and Lichenology (ABLS) II
Location: Sundance 1/Omni Hotel
Date: Tuesday, June 27th, 2017
Time: 2:00 PM
Number: 28003
Abstract ID:145
Candidate for Awards:A. J. Sharp Award