Fig. 2

Modified speed breeding condition combined with speed vernalization (SV + mSB) system enables four generations per year for rapid development of new wheat lines (a) Diagram of SV + mSB conditions. The months marked with yellow indicate one week of speed vernalization (SV) treatment, while blue indicates speed breeding (SB) or modified speed breeding (mSB) conditions. (b) Schematic representation for comparing the generation advancement in traditional field and three SV + mSB conditions. The blue bold generation applies to observed yield trials. Field_1 and 2 represent spring and winter wheat, respectively. The numbers followed by SV + mSB indicate each model using the SV + mSB system starting from different generations. YW3261: Jokyoung/Joongmo2008//Baekkang/m Joongmo2008, YW3228: Milyang46/Garnet, and YW3224: Keumgang/Joongmo2008. Jokyoung, Baekkang and Garnet are spring cultivars, and the others are winter cultivars