The geological isolation of the Australian continent makes it an interesting target for studying angiosperm evolution. In particular, despite having been restricted to only 1% of the continental landmass by extreme climatic transformations, Australian rainforests have retained high levels of biodiversity and endemism, including a high concentration of basal angiosperm lineages. However, the reproductive features of rainforests and their evolutionary history are poorly understood, especially at a continental scale. Understanding how and why current rainforest lineages survived long-term climatic change will help us predict their vulnerability to future change. The aims of this research is to study the evolution and biogeography of the size and colour of flowers and fruits, key characters in the evolutionary history of seed plants that are yet to be investigated.

Related publication:

Delmas et al. (2020) Evolutionary constraints and adaptation shape the size and colour of rainforest fruits and flowers at continental scale. link

There is increasing evidence that global changes negatively impact plant and pollinator populations. However, the ecological and evolutionary consequences of pollinator and mate limitations on plant mating system have been poorly studied. To contribute to this scientific challenge, we study the importance of pollination failure in a self-compatible and mass-flowering shrub (Rhododendron ferrugineum) along a gradient of floral display size. To explore the causes of pollination failure and the consequences on the reproductive success of this focal species, we used an integrative approach including: the study of plant-pollinator interactions at the community scale, pollinator and stigmatic pollen load analyses and the pollination and mating system of the focal species. We also examine, at the species and community levels, the ecological and evolutionary processes that might be able to alleviate pollination failure.

This project was funded by La Fondation pour la Recherche sur la Biodiversité (COMBIO project) and a grant from the french ministry of Higher Education and Research.

Related publications:

Delmas et al. (2016) Pollen transfer in fragmented plant populations: insight from the pollen loads of pollinators and stigmas in a mass-flowering species, PDF

Delmas et al. (2015) Relative impact of mate versus pollinator availability on pollen limitation and outcrossing rates in a mass-flowering species, PDF

Delmas et al. (2014) High lifetime inbreeding depression counteracts the reproductive assurance benefit of selfing in a mass-flowering shrub, PDF

Delmas et al. (2014) Massive floral display affects insect visits but not pollinator-mediated pollen transfer in Rhododendron ferrugineum, PDF

Delmas et al. (2011) Isolation and characterization of microsatellite loci in Rhododendron ferrugineum (Ericaceae) using pyrosequencing technology, PDF

Delmas (2012) PhD Thesis, Interactions plantes-pollinisateurs et reproduction sexuée en habitat fragmenté: Le cas d’un arbuste à floraison massive, PDF