RAD-seq of Cirsium arvense: adult leaf
Genomic DNA was extracted from leaves using NucleoSpin Plant II Genomic DNA Purification kit (Macherey-Nagel, Germany) following the manufacturers instructions. The tissue was homogenized in liquid nitrogen and lysed in PL2 buffer. DNA quality was checked on 1% agarose gel, and DNA concentration was measured using a Qubit 2.0 fluorometer (Thermo Fisher Scientific, USA). To prepare a library, we used 200 ng of DNA per diploid sample and 300 ng for the tetraploid C. vulgare. RADseq library was assembled following Etter et al. (2011) protocol with minor modifications. To cut the DNA, we used PstI restriction enzyme (New England Biolabs, USA).