FACCE ERA-NET+ GrassLandscape (Project Leader: Jean-Paul Sampoux, INRA, France)

Our project aims to implement an innovative methodological frame to screen the natural diversity of a
grassland species in order to discover genetic variability involved in environmental adaptation, and more
specifically in climatic adaptation (Sampoux et al., 2013). We will consider the use of results delivered by this
approach to plan strategies to restore permanent grasslands degraded by climatic shifts and disruptions. Our
project will focus on perennial ryegrass (Lolium perenne L.), which is a major grass species naturally
distributed over the whole European continent as well as in Northern Africa and Near East (Humphreys et al.,
2010). This species is a major component of many natural grassland communities. It is a resource capture
strategy species (Martin et al., 2009) which is especially prevalent in grasslands grazed by cattle. It is also the
main grass species sown in Europe to create temporary meadows and it has therefore received extensive
breeding effort during the last four decades (Sampoux et al., 2011). Recent developments in a new area of
ecological sciences (landscape genomics) have paved the way to the discovery of genomic markers of
adaptive diversity from genome-wide genotyping data. They are based on the implementation of methods
correlating genomic polymorphisms and environmental variations at sites of origin of genotypes combined
with tests of signature of selection (Manel et al., 2010). We will implement this methodological frame to detect
genomic markers of climatic adaptation in the natural diversity of perennial ryegrass. We will use a genotyping
method based on massively parallel sequencing technology applied to a high number of populations obtained
from genebanks of plant breeding research institutes or collected in situ across Europe. We will furthermore
take advantage of know-how and facilities of plant breeding research institutes participating in the project to
phenotype these populations in fields and in controlled environment to record agronomic and ecophysiological
traits. These phenotypic data will be used to model associations between phenotypic variability
and genomic polymorphisms. Association models between genomic polymorphisms and environmental variations will be used to map
the spatial distribution of genomic markers linked to adaptive diversity in present climatic conditions and to
foresee possible shifts in the spatial range fitting these markers in the context of several climate change
scenarios based on the four Representative Concentration Pathways (RCP) of IPCC AR5 (Moss et al., 2010).
On the basis of these results, we will define allelic profiles of perennial ryegrass expected to provide climatic
adaptation at regional scale over Europe under the future climatic conditions foreseen by climate models. We
will consider combining climatic adaptation and value for services (forage production and climate mitigation)
by the recombination of alleles providing climatic adaptation and value for services. We will design several
genetic pools mixing different natural populations for breeding regionally adapted populations to restore
permanent grasslands degraded climatic disruptions. Breeding and releasing improved genetic material will
be out of the scope of the project but will be discussed with stakeholders at the end of the project during ad
hoc meetings for implementation in further collaborative projects.