Submitted to: Evolutionary Applications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2009
Publication Date: 1/28/2010
Publication URL: http://hdl.handle.net/10113/44965
Citation: Dyer, A.R., Brown, C., Espeland, E.K., Mckay, J.M., Meimberg, H., Rice, K.J. 2010. The role of adaptive trans-generational plasticity in biological invasions of plants. Evolutionary Applications. 3(2):179-192. Interpretive Summary: Maternal effects (or, transgenerational plasticity) can have a profound influence on plant performance: the environment determines many aspects of seed formation and subsequent seedling performance. Two identical genotypes can produce very different offspring when the two identical genotypes are grown under different conditions. In this study, we give examples of maternal effects that allow progeny to be extremely successful, and we argue that invasive species are a model system in which to examine maternal effects. Because invasive species are often comprised of only a few genotypes, dynamic responses to the environment that are passed from parent to progeny are a mechanism through which invasive plants can succeed in a wide variety of environments. In this paper we focus on how maternal environments can affect progeny in five different ways 1) increased competitive ability, 2) increased survivorship, 3) direct the distribution of progeny to hospitable environments, 4) increased stress tolerance, and 5) accelerated timing of flowering. We then show how these traits can increase the success of invasive plants and speed the process of plant invasion.
Technical Abstract: Trans-generational plasticity (TGP) that confers greater offspring fitness is likely to be an important mechanism contributing to the spread of some invasive plant species. TGP is predicted for populations found in habitats with predictable spatial or temporal resource heterogeneity, and that have low genetic diversity, are selfing, and for which mean propagule dispersal distances are shorter than the size of resource patches. We suggest that these conditions will often characterize those encountered by populations of invasive species. Using evidence from the literature and two invasive species (Aegilops triuncialis and Cyperus esculentus) as examples, we present five mechanisms through which TGP confers greater maternal fitness: 1) Changes in seed quality and competitive ability can produce more successful seedlings; 2) Increases in propagule pressure and survival via seed traits can increase survival in seasonally variable environments; 3) Directional dispersal of propagules into resource patches can increase maternal fitness; 4) Maternal soil conditions can confer greater stress tolerance in seedlings; 5) Phenological shifts such as early flowering in low resource environments can result in greater stress tolerance. These lines of evidence suggest that the maternal environment can have profound effects on offspring success and that TGP likely plays a greater role in some plant invasions than previously thought.