Restoration genetics of Centaurea jacea and Betonica officinalis using ddRAD derived SNPs. Centaurea jacea Betonica officinalis ddRAD

1. Ecological restoration and plant re-introductions aim to create plant populations that are genetically similar to natural populations to preserve the regional gene pool, yet genetically diverse to allow adaptation to a changing environment. For this purpose, seeds for restoration are sourced from multiple populations in the target region. However, it was only rarely tested whether this strategy indeed leads to genetically diverse restored populations which are genetically similarity to natural populations.2. We used ddRAD derived SNP markers to investigate genetic diversity and differentiation of populations of Centaurea jacea and Betonica officinalis on restored and natural meadows in the White Carpathians, Czech Republic. The meadows have been restored 20 years ago using regional seeds sourced from multiple populations in an approach resembling regional admixture provenancing. To assess temporal changes and alternative seed sources, we also analysed the original seeds used for restoration (only in C. jacea), as well as conventional commercial seeds without certified origin.3. The differentiation between restored and ancient populations (mean pairwise FST = 0.018 in Centaurea and 0.021 in Betonica) was similar to the differentiation among regional natural populations (FST = 0.023 and 0.021), and the restored populations were slightly more genetically diverse than the natural populations. Restored populations were rather similar to seeds from which they have been restored (FST = 0.015). In contrast, conventional commercial seeds were strongly differentiated from the regional populations (FST = 0.100 and 0.059, in Centaurea and Betonica, respectively) and harboured substantially lower genetic diversity. We also found signs of gene flow from ancient to restored populations but not vice versa.4. Synthesis and applications. Regional admixture provenancing is an effective tool to establish genetically diverse populations at natural levels of genetic differentiation.