Translocation experiment and SNP genotyping of candidate genes in adapted and not adapted oak individuals in Europe

For a translocation experiment of oak trees (Quercus petraea), seeds were collected from different provenances in Finland (Punkaharju), Poland (Blizyn), Germany (Solling), Switzerland (Valais) and France (Ventoux) representing a gradient from cold to warmer climatic environments. The oak seeds were planted and germinated under greenhouse conditions in Göttingen, Germany. The seedlings were marked and DNA was extracted from the leaves of each seedling. In total, 6.700 oak seedlings have been planted out again at the different provenance environments. The material was planted in different locations in Europe from Finland to southern France following a common design. Observations of survival and growth have been conducted at the different plantations at least two times per year for the years 2009 and 2010 and 2011. The observations showed that the planted material had differential survival rates over the different plantations. Records of trees that did not survive or survived with signs of maladaptation (slow growth and lack of vitality) as well as records of trees that survived the translocation with normal growth have been kept. The first group of trees was considered as “not adapted trees” while the third group as “adapted trees” to the respective environments.
Equal number of adapted and not adapted trees (1911 individuals in total) has been genotyped at nine nuclear SSR loci to assess neutral genetic structure. The trees of both groups have been also genotyped using the 384 SNPs Illumina GoldenGate assay platform at different candidate genes for oak adaptation. The objective was to detect selection at particular gene loci after translocation in new environments.
The genetic structure of the two groups (surviving and dead plants) in different environments for both neutral SSR and adaptive SNP markers are compared. Differences in the genetic structures between the two groups and the two marker types can help to identify genes which are responsible for tolerance against climatic stressors as drought or cold temperatures.



Patterns of nucleotide variation and gene-associated SNP analysis in a Quercus spp. forest at isocitrate dehydrogensase genes.

Former isozyme research has revealed putatively adaptive significance in some isozyme loci for forest tree species. The NADP+ dependent IDH enzyme (E.C. 1.1.1.42) plays a key role in the citrate cycle of the metabolism of living organisms. As an isozyme, it has often been used in population genetic studies. In some cases it has been suggested that it might not be selectively neutral. Isozyme analysis of the IDH locus has revealed high differentiation between the oak species Quercus. petraea and Q. robur. In the present study, we identified and obtained the nearly complete 3,5 kb sequence of the gene encoding for NADP+ dependent IDH enzyme gene in a sub-sample of 5 samples per species from the four sympatric and closely related species Q. petraea, Q.robur, Q. frainetto, Q. pubescens. Additionally we investigate a number of synonymous, non synonymous and non coding Single Nucleotide Polymorphisms (SNPs), for the total sample set. The results will be compared to the results of the analysis of neutral molecular markers applied in previous work on the same species-rich tree community.