CLIMAGIE: A French INRA Project to Adapt the Grasslands to Climate Change

Climate change in France, central and southern Europe is expected to provoke more frequent and more intense summer water deficits, with increased amplitude in temperatures, exposing the same perennial crops to frosts as well as to heat waves and severe droughts. The impacts on sown monospecific grasslands have been assessed using crop models (Durand et al. 2010) but with less accuracy in extreme situations. Since less work has been done on intra-specific genetic variability there is urgent need to investigate both ranges of climate conditions and genetic variability (Poirier et al. 2012). Phenology and plant productivity responses to water, temperature and nitrogen (N) in particular need to be re-assessed over the full range of temperatures projected in the future

High-Throughput Genome-Wide Genotyping To Optimize the Use of Natural Genetic Resources in the Grassland Species Perennial Ryegrass (Lolium perenne L.)

The natural genetic diversity of agricultural species is an essential genetic resource for breeding programs aiming to improve their ecosystem and production services. A large natural ecotype diversity is usually available for most grassland species. This could be used to recombine natural climatic adaptations and agronomic value to create improved populations of grassland species adapted to future regional climates. However describing natural genetic resources can be long and costly. Molecular markers may provide useful information to help this task. This opportunity was investigated for Lolium perenne L., using a set of 385 accessions from the natural diversity of this species collected right across Europe and provided by genebanks of several countries. For each of these populations, genotyping provided the allele frequencies of 189,781 SNP markers. GWAS were implemented for over 30 agronomic and/or putatively adaptive traits recorded in three climatically contrasted locations (France, Belgium, Germany). Significant associations were detected for hundreds of markers despite a strong confounding effect of the genetic background; most of them pertained to phenology traits. It is likely that genetic variability in these traits has had an important contribution to environmental adaptation and ecotype differentiation. Genomic prediction models calibrated using natural diversity were found to be highly effective to describe natural populations for almost all traits as well as commercial synthetic populations for some important traits such as disease resistance, spring growth or phenological traits. These results will certainly be valuable information to help the use of natural genetic resources of other species

Évolution du genre sexuel et de la diversité génétique dans une succession primaire : l'étude d'Antirhea Borbonica (rubiaceae) sur les coulées de lave à la Réunion

On La Réunion, volcanic éruptions create a tropical forest fragmentation. In this area a gradient of primary succession associated with plant colonisation on lava flows can be identified. We examined thé variability of thé reproductive System and thé genetic diversity in relation to thé ecological processes associated with colonisation and succession. Antirhea borbonica, is a pioneer species which persists into late-successional habitats. This species shows marked variation in thé expression of dioecy. This variation is due to resource limitation in early-succession. Our theoretical models predict that thé gender variation could represent an adaptive plasticity. However, in spite of polliniferous morph fructification, ail populations of this species are close to strict functional dioecy. So, thé high inbreeding coefficients are no due to selfmg and they are probably thé resuit of a Wahlund effect associated with thé colonisation process in primary succession.A La Réunion, l'activité volcanique détruit et fragmente la forêt tropicale humide. La colonisation des coulées de lave crée une série de succession primaire Nous étudions l'évolution du système de reproduction et de la diversité génétique en relation avec les processus écologiques associés à la colonisation et à la succession primaire. Antirhea borbonica est un arbre pionnier qui persiste dans la succession. Cette espèce montre une variation du genre sexuel en fonction du stade successionnel et la capacité de fructification du morphe pollinifère est liée au niveau de ressources. Nos résultats théoriques révèlent que la plasticité du genre sexuel pourrait être adaptative. Mais, bien que le morphe pollinifère fructifie, A. borbonica semble fonctionner comme une espèce dioïque stricte. Ainsi, les fortes valeurs de F;s des populations ne s'expliquent pas par le système de reproduction. Mais une structure agrégée des populations pourrait engendrer de la consanguinité et un effet Walhund

La biodiversité, support des services écosystémiques : nécessité d'une approche multi-échelles

La biodiversité, support des services écosystémiques : nécessité d'une approche multi-échelles. Les Rencontres de l'Inra au Salon de l'Agricultur

Overview of WP4 activities on screening, breeding and phenotyping methods for species mixtures

Overview of the ReMIX (Redesigning European cropping systems based on species mixtures) activities of WP4 "Screening, breeding and phenotyping methods for species mixtures" in the first 2 years

Diversity in plant breeding: a new conceptual framework

Faced with an accelerating rate of environmental change and the associated need for a more sustainable, low-input agriculture, the urgent new challenge for crop science is to find ways to introduce greater diversity to cropping systems. However, there is a dearth of generic formalism in programs seeking to diversify crops. In this opinion, we propose a new framework, derived from ecological theory, that should enable diversity targets to be incorporated into plant-breeding programs. While ecological theory provides criteria for maintaining diversity and optimizing the production of mixtures, such criteria are rarely fully realized in natural ecosystems. Conversely, crop breeding should optimize both agronomic value and the ability of plants to perform and live alongside one another. This framework represents an opportunity to develop more sustainable crops and also a radical new way to apply ecological theory to cropping systems