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In Arnica montana L. (Asteraceae) two subspecies are described, A. montana subsp. atlantica (AMA), present only on the Iberian Peninsula and A. montana subsp. montana (AMM) with a very wide distribution area. The morphological differences between the two subspecies are small and variable. Therefore, this concept is sometimes questioned. To establish the genetic background of the two subspecies, populations of AMA and AMM together with herbarium samples and DNA Bank material of AMM were tested with 12 microsatellite markers. A. montana propagates by seeds or by clonal propagation of its rhizome. In AMA, clonality was frequent while in AMM only one case of clonality could be identified. Therefore, further results were clone-corrected. Genetically, AMA separated very well from AMM with a GST between the subspecies of 0.81, genetically justifying the subspecies concept of A. montana. Genetic variability in AMA (Hexp = 0.28) was lower than in the AMM populations (Hexp = 0.70). A somewhat higher fixation index of AMA (FST = 0.17, compared to an FST = 0.08 for AMM) may indicate that geneflow in AMA is a bit more restricted than in alpine AMM. However, the fixation index of AMA is not deviating from Hardy–Weinberg equilibrium. No inbreeding was observed for AMA (FIS = 0.10) and AMM (FIS = 0.08).

Plant diversity is decreasing mainly through anthropogenic factors like habitat fragmentation, which lead to spatial separation of remaining populations and thereby affect genetic diversity and structure within species. Twenty populations of the threatened grassland species Crepis mollis were studied across Germany (578 individual plants) based on microsatellite genotyping. Genetic diversity was significantly higher in populations from the Alpine region than from the Central Uplands. Furthermore, genetic diversity was significantly positively correlated with population size. Despite smaller populations in the Uplands there were no signs of inbreeding. Genetic differentiation between populations was moderate (F ST = 0.09) and no isolation by distance was found. In contrast, large-scale spatial genetic structure showed a significant decrease of individual pairwise relatedness, which was higher than in random pairs up to 50 km. Bayesian analyses detected three genetic clusters consistent with two regions in the Uplands and an admixture group in the Alpine region. Despite the obvious spatial isolation of the currently known populations, the absence of significant isolation by distance combined together with moderate population differentiation indicates that drift rather than inter-population gene flow drives differentiation. The absence of inbreeding suggests that pollination is still effective, while seed dispersal by wind is likely to be impaired by discontinuous habitats. Our results underline the need for maintaining or improving habitat quality as the most important short term measure for C. mollis. For maintaining long-term viability, establishing stepping stone habitats or, where this is not possible, assisted gene flow needs to be considered.

Aim Species-rich dry grasslands have declined drastically in recent decades leading to spatial isolation of associated species. This can disrupt gene flow leading to genetic erosion, inbreeding and increased differentiation. Using Scabiosa canescens as a case for a threatened central European species confined to dry grasslands, we investigate the genetic consequences of spatial and functional isolation. In particular, inbreeding and loss of genetic diversity are expected to be more pronounced in populations at the northern margin of the sampling area due to more intense agriculture, less suitable habitat and potential post-glacial colonization from the south. Location Germany. Methods We genotyped 563 individuals at 10 microsatellite loci from 22 populations across the species’ range in Germany. We analyse spatial genetic structure and patterns of isolation by distance (IBD) at multiple scales. Further, we identify latitudinal and altitudinal patterns of genetic diversity and inbreeding. Results We found strong population differentiation but no IBD up to at least 200 km. Levels of inbreeding were positively correlated with latitude and tended to decline with altitude. An integration of altitude and latitude into temperature-corrected altitude (CA) was positively correlated with genetic diversity. Populations in the Upper Rhine Valley appear to have a distinct ancestry. Main conclusions We interpret the strong population differentiation combined with no IBD up to at least 200 km as a sign for disrupted extensive gene flow. A trend for reduced genetic diversity towards the northern populations occurring at lower altitudes is probably driven by more intense land use but cannot be conclusively distinguished from other potential factors such as a more recent colonization history. Apart from the distinct Upper Rhine Valley populations, our findings suggest that assisted gene flow up to 100 km would mitigate genetic differentiation, inbreeding and loss of genetic diversity caused by disrupted long-distance dispersal.

Knowledge of within-species genetic diversity can improve effectiveness of conservation measures. These include the mitigation of extinction risks caused by habitat fragmentation, environmental change or diseases as well as site selection for in situ conservation that considers a thorough representation of genotypes. Based on genotyping at twelve nuclear microsatellites we assess genetic diversity of the endangered grassland species Arnica montana . In addition to presenting large scale patterns of genetic diversity, we studied differentiation and inbreeding along altitudinal and latitudinal gradients as well as in relation to population size. Thirty populations (561 individuals) were sampled to represent the species through Central Europe. A broad range of genetic diversity ( H e ) from 0.383 to 0.662 and high levels of genetic differentiation ( F ST = 0.27) were detected. Most variation was found within populations (73%) and not among populations (27%). The majority of populations showed private alleles and a significant pattern of isolation-by-distance. Bayesian analyses of shared ancestry revealed a high number of 24 distinct clusters. Populations at low altitude showed signs of genetic erosion and a tendency for increased clonal reproduction. The strong genetic differentiation of A. montana suggests restricted gene flow among populations. Due to high genetic diversity and no inbreeding, the southern and higher altitude populations in the Alps seem genetically unaffected from genetic erosion despite strong genetic differentiation. The results indicate that in particular lowland populations will depend on human intervention such as assisted gene flow and population reinforcement to avoid further genetic erosion.

We developed ten polymorphic microsatellite markers for the herbaceous species Scabiosa canescens Waldst. & Kit. The species is currently not assessed under the IUCN Red List but has been declining historically due to intensification in agriculture and is recently declining due to habitat loss caused by agricultural abandonment of steppe-like dry grasslands. The microsatellite loci were tested for polymorphism on DNA templates extracted from 26 specimens collected across the species’ range in Germany. Across the ten loci, two to eight alleles were detected with an observed and expected heterozygosity ranging from 0.192 to 0.769 and 0.265 to 0.768, respectively. These newly developed markers provide a valuable tool for population genetic investigations required to design effective conservation measures.

Premise of the study: Polymorphic microsatellite markers were developed for the threatened species Crepis mollis (Asteraceae) to investigate population and conservation genetics. Methods and Results: Illumina sequencing was conducted on pooled genomic DNA from 10 individuals of two populations. Ten polymorphic and 10 monomorphic microsatellite loci with di-, tri-, tetra-, penta-, and hexanucleotide repeat motifs were developed and characterized in C. mollis. In the polymorphic markers, up to 17 alleles per locus were detected with an observed and expected heterozygosity ranging from 0.120 to 0.780 and 0.102 to 0.834, respectively. Furthermore, the polymorphic markers were tested for cross-amplification in three congeneric species (C. biennis, C. foetida, and C. sancta) and amplified in up to three loci. Conclusions: The markers developed in this study are the first microsatellites tested on C. mollis and will be useful for performing population and conservation genetic studies in this threatened species.

Premise of the study: Microsatellite markers were developed to investigate population genetic structure in the threatened species Arnica montana. Methods and Results: Fourteen microsatellite markers with di-, tetra-, and hexanucleotide repeat motifs were developed for A. montana using 454 pyrosequencing without and with library-enrichment methods, resulting in 56,545 sequence reads and 14,467 sequence reads, respectively. All loci showed a high level of polymorphism, with allele numbers ranging from four to 11 in five individuals from five populations (25 samples) and an expected heterozygosity ranging from 0.192 to 0.648 across the loci. Conclusions: This set of microsatellite markers is the first one described for A. montana and will facilitate conservation genetic applications as well as the understanding of phylogeographic patterns in this species.