Abstract Detail

Population Genetics/Genomics

Culley, Theresa [1], Kuenzi Davis, Ashley [2], Ching, Susan N. [3], Sakai, Ann K. [4], Weller, Stephen G. [4].

Down but not out: Genetic variation after a bottleneck and subsequent discovery of additional plants in the rare Hawaiian shrub, Schiedea adamantis St. John (Caryophyllaceae).

Compared to continental taxa, many plant species in the Hawaiian Islands naturally consist of fewer and smaller populations, which are often susceptible to decline due to habitat destruction, invasive species, and climate change. Given this reality, are these insular species fated to extinction or do they still have potential to recover? To explore these questions, we examined  Schiedea adamantis, a federally endangered shrub known only from O'ahu. This species underwent a population crash in the late 1990's, declining from over 250 plants in a single population to only 4 living plants observed by 2011. In 2016, additional individuals that had been consistently missed in earlier surveys were discovered on a steep downslope nearby, resulting in 30 plants total. Subsequently a second population of a few plants was discovered along a cliff face on a nearby mountain range. Using nuclear and chloroplast microsatellite markers, we confirmed that levels of genetic variation had declined in the original bottlenecked population from 2011 but overall levels still remained moderate despite the severe reduction in population size. The four individuals observed in 2011 consisted of one plant that had persisted through the bottleneck, along with its progeny. Genetic variation in the more recently discovered individuals only add to the level within the species. In addition to ongoing reintroduction efforts, detection of moderate levels of genetic variation and discovery of previously unknown existing individuals hold promise for  in situ  survival of the species, but only if its habitat can be protected from fire, increased drought, and competition from invasive species.  

Related Links:
Culley Lab Website

1 - University Of Cincinnati, Department Of Biological Sciences, 614 Rieveschl Hall, Cincinnati, OH, 45221, United States
2 - Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology & Cancer Biology, Cancer & Blood Diseases Institute, Cincinnati, OH, 45229, USA
3 - Hawaii Division of Forestry & Wildlife, Dept. Land & Natural Resources, 2551 Waimano Hm. Road, Room 202, Pearl City, HI, 96782, USA
4 - University of California, Irvine, Ecology & Evolutionary Biology, 365 SH, Irvine, CA, 92697, USA

Keywords:
Genetic diversity
Hawaiian Islands
Schiedea
Bottleneck.

Presentation Type: Oral Paper
Session: PGG2, Population Genetics and Genomics II
Location: /
Date: Wednesday, July 21st, 2021
Time: 10:30 AM(EDT)
Number: PGG2003
Abstract ID:937
Candidate for Awards:None