DNA extraction and genotyping-by-sequencing
Genomic DNA was extracted using the CTAB protocol of Brock, Dönmez,
Beilstein, & Olsen (2018), which was modified from Webb & Knapp
(1990). Genotyping-by-sequencing (GBS) libraries were prepared following
Poland & Rife (2012), using a double digest of Pst I andMsp I. Samples were sequenced on three lanes of the Illumina HiSeq
2500 platform with 1x100 reads at the Roy J. Carver Biotechnology Center
at the University of Illinois Champaign-Urbana.