Fig. 1

PCR fragments verifying circle closure prediction for two scaffolds sc_5_circ and sc_8_circ of Abies alba. Presence of a PCR amplification product of expected size indicates circular connection of two opposing ends of a given scaffold. Primer sequences are presented in Additional file 1: Table S2. Aa19 – HMW-DNA of the Abies alba reference tree AA_WSL01; Aa2g – total DNA of AA_WSL01; total DNA of two other Abies alba individuals, 2726a and 2726b