• Helosciadium repens (Jacq.) W.D.J. Koch is threatened by genetic erosion. It is a Crop Wild Relative (CWR) of celery and celeriac and a potentially valuable genetic resource for plant breeding. The objective of this study was the analysis of distribution of genetic diversity with a set of selected populations in Germany. The results of the genetic analysis and data obtained during the site visits were used to identify a subset which was chosen to best represent the genetic diversity of H. repens in Germany. The chance of long‐term conservation by securing the identified populations in genetic reserves is distinctly possible.
• Seven hundred and fifteen individuals from 27 sites were assessed using six simple sequence repeat markers. Discriminant analysis of principal components was used to identify six clusters of genetically similar individuals. The complementary compositional genetic differentiation Δj was calculated to designate a subset of populations chosen to best represent the overall genetic diversity. Entry 18R (Δ_18R = 0.2498) represented its pooled remainder the best, while entry 22R (Δ_22R= 0.4902) differed the most from its complement.
• Based on the results of the genetic analysis and information regarding the current conservation status, 14 most appropriate wild populations for potential genetic reserve were identified. The used markers display a low level of genetic variation between the analyzed populations, and a split between Northern and Southern populations was observed.
• CWR species are essential genetic resources for plant breeding and food security. However, 11.5% of the European CWRs are threatened. Therefore, it is of utmost importance to determine their genetic compositions. These insights will provide the fundamental basis for making crucial decisions concerning future conservation strategies for H. repens.

Explanations for SSR_datamatrix_H_repens.xlsx

• Primer set - name of the primer set used
• Population - Population code in the GeSell Project
• Individual - code of the individual
• Low - lowest bp length of the allele
• High - highest bp length of the allele