Thesis
Sex: risky business in the cold? Reproductive allocation and genetic diversity in the circumpolar plant Bistorta vivipara (Polygonaceae)
Washington State University
Master of Science (MS), Washington State University
2014
Handle:
https://hdl.handle.net/2376/102414
Abstract
Successful sexual reproduction requires more energy and is more time consuming than asexual reproduction. In the Arctic, where energy budgets are tight and the growing season is short, species with mixed-mating systems dominate. Plants with these adaptations thrive because they can alter reproduction depending on environmental conditions. Bistorta vivipara is a circumpolar herb that predominately reproduces asexually through bulbils, but certain environmental conditions promote higher investment in flowers and the possibility of sexual reproduction. Despite largely reproducing asexually, high levels of genetic diversity have been observed in this species. The factors contributing to this diversity remain unclear. We aim to examine how various environmental factors relate to investment in bulbils versus flowers and whether higher investment in flowers (sexual reproduction) is correlated with higher levels of genetic diversity. We sampled twenty populations of B. vivipara across the high Arctic archipelago Svalbard. In each population, we measured reproductive traits, environmental variables, and collected samples for genetic analyses. Comparative analyses were used to examine relationships among the collected data. Sites at lower elevations with higher soil C:N ratios, soil organic matter, and v lower pH appeared to positively influence investment in sexual reproduction. The overall genetic structure and diversity levels were consistent with those of a predominantly clonal species; however, increased investment in sexual reproduction significantly correlated with higher numbers of genotypes per population. In sub-optimal environments, there is an increase in asexual reproduction and a decrease in sexual reproduction. Our data indicate that occasional out-crossing, long-distance dispersal, and a long-life span are all factors that are important in maintaining genetic diversity in B. vivipara.
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Details
- Title
- Sex
- Creators
- John Walter Bills
- Contributors
- Eric H. Roalson (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Sciences, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525037101842
- Language
- English
- Resource Type
- Thesis