During the first 72 months of the project:
We have conducted six exhaustive surveys (2016-2021) of the six natural populations occurring in the fragmented habitat of the abandoned saltmarsh between Peyriac de Mer and Bages in Southern France and characterized >18000 plants in natural populations (phenotype, geographic coordinates, 25 genetic [microsatellite] marker genotypes, microenvironment on the basis of photos). We have mapped the geographic patches were environmental conditions are more likely to be shared (e.g. open habitat on rocks, grassland). We have constructed the pedigree by genetically assigning parenthood to reach >5000 plants included in a highly reliable pedigree.
Experiments in controlled conditions allowed us to expose plants to different treatments (different levels of shade exposure and climate conditions). Experiments conducted in natural conditions were used to identify traits that might be involved with snapdragon plant adaptive evolution. Other experiments conducted in more controlled conditions (greenhouse and growth chambers) were conducted to test for an epigenetic basis of trait variation, with a focus on the developmental response to shade of snapdragon plants. We used Antirrhinum majus highly inbred lines and Arabidopsis thaliana Recombinant Inbred Lines, where the genome was fixed by generations of self-fertilization into a homozygous state, to investigate fundamental ecological and evolutionary mechanisms related to epigenetic trait variation.
Our results on natural populations (WP1-2-3) were published in several peer-reviewed articles in international journals (e.g. Evolution, Open Research europe) and presented in international conferences (e.g. ESEB) and local seminars (e.g. Vienna, Montpellier). They imply low connectivity between fragmented populations, fluctuating selection at an extremely small spatial-scale, and low genetic heritability for fitness related traits.
Our experimental results (WP4) were also published in several peer-reviewed articles in international journals (e.g. Molecular Ecology) and presented in international conferences and local seminars. They imply that snapdragon plants exhibit strong phenotypic plasticity in response to shade (SLA, stem elongation in response to shade, etc.) that are associated with some epigenetic changes in methylation patterns.
In terms of theoretical and conceptual developments (WP5). We have developed and published a methodological guide and review articles (e.g. Trends in Ecology & Evolution) on how and why the potential role of epigenetic and genetic variation in the response to selection should be studied simultaneously and what are the potential implications for agronomic sciences.
