Genetic structure and evolution of diploid Cochlearia in Iceland ...

• Main Authors: Brysting, Anne Krag, Olsen, Luka Natassja, Brandrud, Marie Kristine, Mandakova, Terezie, Lysak, Martin, Bjorå, Charlotte Sletten, Cires, Eduardo, Nordal, Inger
• Format: Dataset
• Language: English
• Published: Dryad 2021
• Subjects: FOS: Biological sciences; Arctic; Nordal; Iceland
• Online Access: https://dx.doi.org/10.5061/dryad.d51c5b04s; https://datadryad.org/stash/dataset/doi:10.5061/dryad.d51c5b04s

Within the northern European Cochlearia (Brassicaceae), considerable chromosome variation has taken place without corresponding morphological differentiation, which has resulted in an intricate species complex including two base chromosome numbers and several ploidy levels. Here, we dig into the situation in Iceland. The distribution, genetic structure, taxonomy and origin of the two Cochlearia cytotypes (2n = 12 and 2n = 14) present in Iceland are discussed. Chromosome counts indicate that the 2n = 12 populations are dominating along the coast, whereas only 2n = 14 has been reported for inland alpine populations. RADseq data support geographically structured genetic variation along the Icelandic coast, as well as environmentally structured genetic differentiation between coastal and alpine populations. The alpine populations show genetic and morphological affiliation with C. groenlandica (2n = 14), which is widely distributed in the Arctic, but more comprehensive sampling is needed to conclude on the ... : Morphology: We measured leaf traits on pressed material from both field-collected plants and plants cultivated in controlled conditions. When possible, we measured five leaves from five samples per population. The following leaf traits, previously recognized by Nordal & Laane (1990) as informative, were measured/calculated: length (L), width (W), leaf ratio (W/L), and leaf base angle (Supporting Information, Fig. S1). For five populations, we measured flower traits on field-collected and cultivated plants. When possible, we measured three flowers from four samples per population. The following flower traits were measured/calculated: petal length (PL), petal width (PW), sepal length (SL), petal ratio (PW/PL) and sepal-petal ratio (SL/PL). RADseq: We prepared a RADseq library using single digest, double barcoding and size selection with magnetic beads according to a protocol adapted from Baird et al. (2008) and Paun et al. (2016), with modifications as in Brandrud et al. (2017). The library was sequenced ...