[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-widesignatures of drought adaptation in two widespread European Fagaceaeusing environmental, genomic, and phenotypic data

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

The trendtowards extremes in environmental conditions has led to increasedmortality, for example in Europe, after the unprecedented heat wavesand drought periods having occurred in recent years.

Betterunderstanding the impact of those extreme and rapid environmentalshifts on tree populations is important i) to assess the adaptivepotential of each population in regard to its future habitat, and ii)to characterise sources of adaptive genomic variation that ultimatelymight be used for assisted migration.

Yet, little is known about thegenetic mechanism underlying climate adaptation of tree species atthe continental scale and about their capability to adapt to rapidlychanging conditions given their long generation time.

In thiscontext, we investigated the genetic underpinnings of adaptation todrought resistancein the two ecologically and economically importantEuropean Fagaceae trees, Fagus sylvaticaand Quercus petraea, througha combined analysis of environmental, phenotypic, and genomic data.

In the course of the H2020 project GenTree, we sampled twelve andnine population pairs in contrasting environments across Europe forF. sylvaticaand Q. petraea, respectively.

Using climatic,topographic, and soil variables, we generated various drought indicesto model ecological constraints at high spatial resolution (i.e.individual tree level), covering past and present local habitats of600 and 490 individuals for F. sylvaticaand Q. petraea, respectively.

Also, we utilised in situphenotype measurements and wood cores ofindividual trees to produce drought-related phenotypic traits derivedfrom tree-ring series.

An in-depth exome-capture sequencing providedabout 17 (F. sylvatica) and 8 (Q. petraea) million SNPs. We carriedout genotype–environment association analyses that allowed us toidentify loci potentially under selection by drought-relatedenvironmental factors.

Then, we will investigate phenotype–genotypeassociations to search for genes underlying important drought-relatedtraits. Finally, we will discuss similarities and differences inadaptive signatures in the two related species and drawrecommendations for forest management under future climate scenarios.