Fig. 1: Parallel adaptation of Arabidopsis arenosa to challenging serpentine soils.
a Locations of the investigated serpentine (S, green) and non-serpentine (N, violet) populations sampled as spatially proximate pairs (numbers) in Central Europe with an illustrative photo of an S population (photo was taken by F. Kolář). b Allele frequency covariance graph of populations based on ~870,000 fourfold-degenerate SNPs; asterisks show the 100 bootstrap branch support. The outgroup (OUT) is represented by a tetraploid population from Western Carpathians, the ancestral area of tetraploid A. arenosa93. c Two contrasting evolutionary scenarios of serpentine colonisation compared in coalescent simulations; the topology assuming independent serpentine colonisations (framed in green) received the highest support consistently across all 10 pairwise combinations of S–N population pairs. d Differences in Ca/Mg ratio and in Ni concentrations [µg/g] in S and N soils from the original sampling sites (n = 78 individual samples, one-way ANOVAs: F1,77 = 26.5, p = 1.94e−06 and F1,77 = 117.4, p = 2.01e−16 for Ca/Mg and Ni, respectively). e Differences in maximum rosette size of three population pairs attained after 3 months of cultivation in local serpentine and non-serpentine substrates (significance of the soil treatment × soil origin interaction in a two-way ANOVA is indicated: F1,90 = 21.6, p = 1.17e−05, F1,96 = 12.3, p = 6.88e−04, and F1,85 = 42, p = 5.68e−09 for population pairs 1, 2 and 3, respectively). f Example photos illustrating parallel growth response in the three population pairs to serpentine soils (green frame) depending on the soil of origin (dot colour) (photo was taken by V. Konečná). g Differences in ion uptake between originally S and N individuals when cultivated in serpentine soils; Ni concentrations were standardised by corresponding soil Ni values (n = 28 individual samples, one-way ANOVAs: F1,27 = 6.2, p = 0.019 and F1,27 = 13.5, p = 0.001 for Ca/Mg ratio and Ni, respectively). Points denote mean, error bars depict standard error of mean in charts e, d, g. Source data underlying Fig. 1d, g are provided as a Source data file.
