2018

Sonja Kujala (Luke)

Convergent adaptation in northern Pinus sylvestris and Picea abies?-Genotyping the Evoltree ISS Punkaharju

This project examines the level of sharing of adaptive genomic variation between Finnish and Swedish populations of Pinus sylvestris (Scots pine) and Picea abies (Norway spruce).

These species in the northern parts of their distribution have similar demographic history (colonization of Fennoscandia after Last Glacial Maximum), and have adapted to similar environmental challenges. In these northern latitudes, traits like timing of yearly growth and cold tolerance are likely to have significant fitness effects as the plants have to maximize their growth, yet develop sufficient cold tolerance each year. Growth rhythms and cold tolerance have significant genetic component in conifers, seen as considerable heritabilities and evident latitudinal adaptive variation (Heide 1974; Aho 1994; Hurme et al. 1997; Howe et al. 2003; Chen et al. 2012; Kujala, Knürr et al. 2017). Earlier QTL mapping and association studies have found many loci associated with these traits in a variety of conifer species (e.g. Hurme et al. 2000; Eckert et al. 2009; Holliday et al. 2010; Kujala, Knürr et al. 2017).

The P. sylvestris genotyping and association analyses of this work are being done on an EVOLTREE Intensive Study site for P. sylvestris, located in Punkaharju, Finland. The funding is being used for genotyping the 500 mother trees of Punkaharju ISS.

• Project report (2022)

Christian Rellstab (WSL)

OAKID2-Transferability and phylogenetic extension of species-diagnostic SNP markers in European white oak species

The project is a collaboration between the two EVOLTREE partners WSL and INRA Pierroton, which  have established a fruitful long-term cooperation (e.g., Gerber et al., PLOS ONE, 2014; Rellstab et al., Mol. Ecol.,2016) over the past years.

The project investigates a technically and scientifically interesting topic in forest genetics that is of practical and scientific relevance for the research community of EVOLTREE. Specifically, oaks included in the permanent samples from the four ISS Landes, Ventoux, Valais, and Solling will be included in the test array, and results can be compared to nuclear microsatellite markers previously genotyped at WSL (using the 8-plex of Guichoux et al., Mol. Ecol. Resour., 2011).

The optimised species diagnostic SNP set, in combination with the freely available assignment pipeline in R, can be used to assign taxa to oak trees from other EVOLTREE ISS populations and TREETYPE individuals. Since species assignment in oaks is often difficult, this will help increase the quality of the site and tree data in these two EVOLTREE resources. All SNP data will be entered in the EVOLTREE SNP DATABASE.

• Project report 2022