iDiv Conference 2024

Unveiling the role of phenotypic plasticity and adaptation using a grassland biodiversity experiment

14 Nov 2024, 15:30

15m

Leipziger KUBUS/2-AB - Hall 2 (Leipziger KUBUS)

Talk Molecular Biodiversity and Evolution Talk Session

Speaker

Francesca De Giorgi

Description

1. In the last years, biodiversity experiments showed how varying plant species diversity and its associated changes in abiotic and biotic environment produce phenotypic changes in plant species. However, it is still not clear what is the role of adaptation and phenotypic plasticity in shaping these phenotypic responses, and whether the environmental heterogeneity typical of highly diverse communities could increase phenotypic plasticity.
2. To test this, we conducted a two generations common garden experiment using seed families of 16 populations of the clonal herb Taraxacum officinale, grown in plant communities of different species diversity in a 17-year-old grassland biodiversity experiment (Jena Experiment). For two generations, we used clones of each seed family, which we previously genotyped, and we assigned offspring of each clone to a light or shade treatment to simulate differences in light availability between high- and low-diversity communities. We then compared their performance and trait expression in relation to their selection history in the biodiversity experiment and the treatment in which they grew.
3. Increasing species richness was associated with an increase in inflorescence length and leaf greenness. We identified significant interactions between species richness and treatment for biomass production, number of inflorescences, leaf length and leaf greenness. Regarding values of phenotypic plasticity, selection in high-diversity communities lead to a decrease in phenotypic plasticity in the number of leaves in the first generation. However, this effect disappeared in the second generation in favor of an effect of parental treatment.
4. Overall, history of selection in communities of different diversity induced adaptive phenotypic responses visible after more than one generation in a common garden. We could confirm the important role of phenotypic plasticity for a quick adjustment to the environment, but we found only weak indications of selection for increased phenotypic plasticity in highly diverse communities.