Using genomics to guide seed-sourcing at the right taxonomical level for ecological restoration projects: the complex case of Carex bigelowii s.lat. in Norway

• Main Authors: Westergaard, Kristine Bakke, Kyrkjeeide, Magni Olsen, Brandrud, Marie Kristine
• Format: Other/Unknown Material
• Language: unknown
• Published: 2022
• Subjects: double-digest restriction site-associated DNA sequencing (ddRAD-seq); Carex bigelowii; Norway
• Online Access: https://zenodo.org/record/5603319; https://doi.org/10.5281/zenodo.5603319

There is a growing demand for ecological restoration using suitable seeds following international standards or national legal demands for local seed-sourcing. However, before selecting the appropriate geographic origin of seeds, it is vital to explore taxonomic complexity related to the focal taxa. We used ddRAD-seq to screen genomic diversity within Carex bigelowii s.lat. focussing on Norway. This species complex is considered a candidate for seeding, but presents considerable morphological, ecological, and genetic variation. The genetic structure of 132 individuals of C. bigelowii s.lat., including C. nigra as an outgroup, was explored using ordinations, clustering analyses, and a genetic barrier algorithm. Two highly divergent clusters were evident, supporting the recognition of two taxonomic units 'C. dacica' and 'subsp. bigelowii'. Previously defined seed-sourcing regions for C. bigelowii s.lat. did not consider the known taxonomic complexity, and therefore interpreted the overall genetic structure as seed-sourcing regions, not taxa. We estimated genetic neighbourhood sizes within each taxon to be 100-150 km and 300 km, respectively, indicating species-specific delimitations of local seed-sourcing regions. Frequent hybrids, local genetic distinctiveness, and suggested ecotypes add complexity to the discussed seed-sourcing regions. Our results show how genomic screening of diversity and structure in a species complex can alleviate the taxonomic impediment, inform practical questions and legal requirements related to seed-sourcing, and together with traditional taxonomic work provide necessary information for a sound management of biodiversity. Uploaded file "Pop_vs_Sample_vs_CollectorsID" lists the pop_ID, Sample_ID_vcf and the Voucher_ID for all samples. pop_ID is the site number as listed in Table 1 in the publication. Sample_ID_vcf is the individual sample ID as used in the dataset files A and B Voucher_ID is the individual herbarium/DNA-collection identification for each samples, also listed in Table 1 ...