Canal-U

[COLLOQUE] GENTREE Final Conference 27-31 January 2020 séance 8

GENTREE Final Conference :

Benjamin DAUPHIN - WSL Birmensdorf · Switzerland

GENTREE Final Conference 'Genetics to the rescue - managing forests sustainably in a changing environment'

27-31 January 2020, Avignon, France

http://www.gentree-h2020.eu/

Benjamin DAUPHIN - WSL Birmensdorf · Switzerland : Range-wide signatures of drought adaptation in two widespread European Fagaceae using environmental, genomic, and phenotypic data

As a consequence of ongoing climate change, forests are increasingly subjected to temperature- and drought-induced stresses.

The trend towards extremes in environmental conditions has led to increased mortality, for example in Europe, after the unprecedented heat waves and drought periods having occurred in recent years.

Better understanding the impact of those extreme and rapid environmental shifts on tree populations is important i) to assess the adaptive potential of each population in regard to its future habitat, and ii) to characterise sources of adaptive genomic variation that ultimately might be used for assisted migration.

Yet, little is known about the genetic mechanism underlying climate adaptation of tree species at the continental scale and about their capability to adapt to rapidly changing conditions given their long generation time.

In this context, we investigated the genetic underpinnings of adaptation to drought resistancein the two ecologically and economically important European Fagaceae trees, Fagus sylvaticaand Quercus petraea, through a combined analysis of environmental, phenotypic, and genomic data.

In the course of the H2020 project GenTree, we sampled twelve and nine population pairs in contrasting environments across Europe for F. sylvaticaand Q. petraea, respectively.

Using climatic, topographic, and soil variables, we generated various drought indices to model ecological constraints at high spatial resolution (i.e. individual tree level), covering past and present local habitats of 600 and 490 individuals for F. sylvaticaand Q. petraea, respectively.

Also, we utilised in situphenotype measurements and wood cores of individual trees to produce drought-related phenotypic traits derived from tree-ring series.

An in-depth exome-capture sequencing provided about 17 (F. sylvatica) and 8 (Q. petraea) million SNPs. We carried out genotype–environment association analyses that allowed us to identify loci potentially under selection by drought-related environmental factors.

Then, we will investigate phenotype–genotype associations to search for genes underlying important drought-related traits. Finally, we will discuss similarities and differences in adaptive signatures in the two related species and draw recommendations for forest management under future climate scenarios.