Abstract Detail

The evolution of functional traits in plants: is the giant still sleeping?

Gianoli, Ernesto [1], Escobedo, Victor [2].

Phenotypic plasticity and intraspecific trait variation: a test of a not obvious relationship.

Intraspecific trait variation (ITV) is widely recognized as a key requisite for the evolutionary success of populations. However, its relevance at higher levels of biological organization has been largely neglected. A new emphasis on ITV is emerging because it can provide insights into community assembly processes. Phenotypic plasticity is considered as one of the main sources of ITV, particularly in heterogeneous environments. Therefore, it could seem obvious that ITV should correlate positively with phenotypic plasticity. Despite the appealing simplicity of this notion, there is not only a paucity of empirical evidence but also a lack of understanding of the implications of the interplay between ITV and plasticity. Thus, i) ITV should increase with increasing levels of plasticity when the selective optimum differs among environments and genetic variation is limited; ii) ITV and plasticity may be unrelated when there is enough genetic variation to respond to the selective environments; iii) ITV and plasticity may show a negative relationship when organisms, due to the absence of reliable environmental cues, produce a range of different phenotypes that do not match the environment, i.e., maladaptive plasticity. Using as study system six annual plant species from an arid shrubland, we evaluated in a greenhouse experiment whether ITV and plasticity are positively related across different conditions of water availability (wet vs dry treatments) and light availability (sun vs shade treatments). These experimental treatments resemble the natural setting of microsites in that shrubland. We measured 12 functional traits and Grime’s ecological strategies (competitor-, stress tolerator-, ruderal-strategy). To estimate ITV we used the total coefficient of variation for each trait per species, whereas to estimate phenotypic plasticity we used the coefficient of variation across environments. We found that 6 out of 12 functional traits and 2 out of 3 ecological strategies showed a positive relationship between ITV and phenotypic plasticity. To gain a better understanding of the interplay between phenotypic plasticity and ITV, further research should include field data of trait-fitness associations.

1 - Universidad de La Serena, Departamento de Biología, La Serena, Chile
2 - Universidad de La Serena, Departamento de Biología, Depto Biologia, La Serena, Chile

Keywords:
phenotypic plasticity
intraspecific trait variation
functional traits
arid enviroments.

Presentation Type: Colloquium Presentations
Session: CO04, The Evolution of Functional Traits in Plant: Is the Giant Still Sleeping?
Location: Tucson J/Starr Pass
Date: Monday, July 29th, 2019
Time: 2:15 PM
Number: CO04004
Abstract ID:682
Candidate for Awards:None