VRN1, FT, and VRN2L gene expression with and without cold treatment of imbibed seeds. Imbibed seeds were given a subsaturating (short cold) vernalization treatment (1 week at 5°C for Bd21 and Bd21-3; 3 weeks at 5°C for Bd1-1) or a saturating (long cold) vernalization treatment (3 weeks at 5°C for Bd21 and Bd21-3; 7 weeks at 5°C for Bd1-1). Leaf 2 was harvested 11 d after removing from cold (B–D) or from emerging shoot tissue at the end of the cold treatment (A). Tissue was harvested at a similar stage of development from nonvernalized controls. Plants were grown in a 16-h photoperiod during and after vernalization. For C, Bd1-1 was treated for 6 weeks of cold. A, RT-qPCR of VRN1 in shoot tissue of Bd21, Bd21-3, and Bd1-1 during cold treatment. B, RT-qPCR of VRN1 in leaf 2 of Bd21, Bd21-3, and Bd1-1 after cold treatment. C, RT-qPCR of FT in leaf 2 of Bd21, Bd21-3, and Bd1-1 after cold treatment. D, RT-qPCR of VRN2L in leaf 2 of Bd21, Bd21-3, and Bd1-1 after cold treatment. Bars represent mean of three biological replicates ± se. Black indicates Bd21, gray indicates Bd21-3, and white indicates Bd1-1. NV, Nonvernalized; V, vernalized.