On-going research projects

Varietal mixtures as a tool to develop sustainable agriculture: elucidating the mechanisms that drive genotypic interactions in durum wheat

Varietal mixtures have been proposed as a way to take better advantage of biological and ecological processes naturally occurring in ecosystems, allowing the development of more sustainable agrosystems with reduced environmental costs. To date, agronomic studies of varietal mixtures have only remained descriptive, making it impossible to predict mixing effects of specific mixtures. Many plant studies have shown that individual phenotypes can strongly depend upon the degree of relatedness among individuals that interact. Niche partitioning and kin recognition have been proposed as the main mechanisms that drive the emergence of such patterns. However, attempts to quantify the role of those mechanisms on the evolution of phenotypic traits have been scarce, especially in plants. The general aim of the project is to disentangle the mechanisms that drive interactions between genotypes with a special emphasis on the role of human selection on kin interactions along the domestication process in durum wheat.

Collaborators : Alain Audebert, Jacques David, Martin Ecarnot, Marie-Hélène Muller, Pierre Roumet (AGAP, Montpellier), Florian Fort, Cyrille Violle (CEFE, Montpellier), Nicolas Rode (CBGP, Montpellier), Jean-Benoît Morel and Elsa Ballini (BGPI, Montpellier), Christophe Salon and Christian Jeudy (Agroécologie, Dijon)

BREEDING FOR COOPERATIVE CROPS

In agriculture, intraspecific competition is undesirable, since it drives the evolution of traits toward phenotypic values lowering group performance. Plant height is a well-documented example: tall plants win access to light over shorter plants by diverting resources to vegetative structures, which leads to a negative correlation between height and yield. Breeding for cooperative phenotypes that do not invest resources in competitive interactions at high planting density could help sparing natural land from conversion to agriculture. Still, apart from height, we know very little about the traits that drive plant- plant interactions. Using durum wheat (Triticum turgidum subsp. durum) as a model species, we combine field and controlled experiments, and theoretical work to:

(1) identify traits involved in plant-plant interactions, and the genetic bases of cooperative phenotypes

(2) test whether cooperation has evolved during domestication and subsequent breeding

(3) design breeding schemes that promote plant cooperation and optimize crop yield in high-density agrosystems

Collaborators : Germain Montazeaud (PhD student), Jacques David, Pierre Roumet, and Muriel Tavaud (AGAP, Montpellier), Florian Fort, Sylvain Gandon, and Cyrille Violle (CEFE, Montpellier), Jean-Benoît Peltier (BPMP, Montpellier), François Rousset (ISEM, Montpellier)

Ecological and biological factors promoting endemism in Mediterranean plants

The Mediterranean flora is characterized by a high rate of endemism. Among the endemic species, 60% are narrowly endemic, that is, species whose distribution is restricted to a single well-defined area within a small part of the Mediterranean region. Furthermore, many of those narrowly endemic species represent examples of disjunct distributions of closely related taxa. We aim to unravel the mechanisms that lead to diversification, rarity and extinction, using species from the section Maculosae of the Centaurea genus as model species.

Collaborators : Bruno Colas (ESE, Orsay), Isabelle Olivieri, Agnès Mignot, Sandrine Maurice, Eric Imbert (ISEM, Montpellier), Miquel Riba (Université Autonome de Barcelone)

Effects of past climate change on the distribution of tropical rainforest species

The aim of the project is to assess the influence of past climate variations on the present distribution of neotropical forest species, using genetic tools. The model species is the understorey palm Astrocaryum sciophilum (Miq.) Pulle (Arecaceae), endemic to the tropical rain forests of the Guiana Shield.

Collaborators: Bernard Riéra (UMR 7179, Brunoy), Renaud Vitalis and Raphaël Leblois (CBGP, Montpellier)