| Abstract Detail
Ecology Turner, Isabelle [1], Oakley, Christopher [1]. Can regional admixture provenancing increase fitness in restored populations of a rare prairie forb? Many prairie species are at greater risk of extinction due to habitat loss, reduced genetic variation needed to adapt to environmental change, and stochastic fixation of deleterious alleles. Less than 10% of native prairie habitat remains, so one strategy to preserve biodiversity is active site restoration by seeding with prairie species. The efficacy of such restorations critically depends on where the seeds are provenanced from. Highly local seed provenancing preserves adaptation to local conditions, but seeds from small remnant populations may have low fitness due to fixed deleterious alleles and limited genetic variation to adapt to future change. Provenancing seeds from more distant locations may alleviate the genetic consequences of small populations, but this may come at a loss of local adaptation and/or decreased fitness via genetic incompatibilities (i.e. outbreeding depression) between populations. Regional admixture provenancing -collecting seed from multiple regional populations- has recently been proposed as a compromise between increasing genetic variation and retaining local adaptation. Using three remnant populations of the regionally rare perennial plant Silene regia Sims (Caryophyllaceae), I experimentally test the maximum potential success of regional admixture provenancing for restorations by examining heterosis in crosses between populations. Heterosis is an increase in fitness of between population crosses relative to within population crosses and is expected to result from dominance complementation of deleterious recessive alleles that have been fixed within remnant populations. Crosses between populations mimic the result of regional admixture provenancing after one generation, and heterosis may provide a more immediate fitness advantage than that expected from increased genetic variation for adaptation to environmental change. We performed more than 600 hand pollinations within and between populations and have thus far quantified seed number per fruit, germination percentage, and juvenile survival. Ongoing experiments will quantify survival and fruit production in both greenhouse and field common gardens. Preliminary analyses suggest heterosis (or outbreeding depression for negative values) is variable across populations and fitness components. Population level estimates of heterosis ranged from 0% to 47% for seed number per fruit, -12% to 12% for germination proportion, and -8% to 14% for juvenile survival. Ongoing experiments will obtain fitness components for a more complete portion of the life cycle, but data thus far suggest that heterosis arising from regional admixture provenancing for Silene regia could depend on the source populations included.
Log in to add this item to your schedule
1 - Purdue University, Botany & Plant Pathology, 915 West State Street, West Lafayette, IN, 47906, USA
Keywords:
heterosis
prairie
regional admixture provenancing
restoration genetics
Seed Sourcing
Silene regia.
Presentation Type: Poster
Session: P1, Ecology Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1EC011
Abstract ID:767
Candidate for Awards:None |
