Betula halophila, Betula microphylla, Betula pendula and Betula tianshanica raw sequence reads

Betula microphylla and Betula halophila are endangered species in the northern Xinjiang province, northwest China, where they occur with the abundant Betula pendula. The species status of B. halophila and the extent of gene flow between B. microphylla and B. pendula remain unclear. Here, we resolve the identity of B. halophila and assess the extent of gene flow between B. microphylla and B. pendula using restriction-site associated DNA sequencing (RADseq). We sequenced 40 B. pendula individuals from eight populations, 40 B. microphylla individuals from five populations, one B. halophila and an additional seven individuals of B. tianshanica from one population.