[COLLOQUE] GENTREE Final Conference 27-31 January 2020 séance 3

GENTREE Final Conference : Bartosz ULASZEWSKI - Kazimierz Wielki University Bydgoszcz · Poland 

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/

Bartosz ULASZEWSKI - Kazimierz Wielki University Bydgoszcz · Poland : Spatial genetic structure of European beech and outlier SNPs analysis of multiple European beech (Fagus sylvatica L.) populations based on ddRAD analysis.

Reduced representation sequencing techniques like ddRADseq or GBS canbe very useful for discovering vast sets of genomic markersapplicable in multiple types of studies.

From thousands of gatheredSNP, it is possible to search for patterns of structure, migration,genome-environmental (GxE) associations or signs of selection. In ourstudy, we have used the available reference sequence of Fagussylvatica (Mishra et al. 2018) to analyze 60 Gbp of ddRADseq datafrom 1068 individuals which originated from 85 cross-European sites.

The SNP-calling gave 18021 SNPs present in at least 95% of thesamples with minor allele frequency >0,05. Genetic structureanalysis revealed three distinct clusters that seem to overlappotential glacial refugia and postglacial migration routes of thisspecies. Associations of SNP outliers were tested using threemethods: Sambada (Stucki et al. 2017) and LEA-LFMM (Frichot &François 2015) which also use temperature and rainfall climatic data(Hijmans et al. 2005) and BayeScan (Foll & Gaggiotti 2008).

Wehave found >100 markers under selection confirmed by at least twomethods. Analysis of those abovementioned SNPs showed thatpopulations on the eastern border of the species range tend to havesignificantly higher Fst with lower heterozygosity and allelicrichness. This is a signal that those populations are under seriousthreat with increasing negative effects of climate change on beech.

Discovered structure and allele frequencies of outlier SNPs provideevidence that reference-based genomic variance analysis is a usefultool for predicting response to change of local and species-rangedbioclimatic conditions.