Photoperiodic flowering time screening
Sixteen plants per line were sown into soil trays with 24 cells with the positions being allocated randomly. The seeds were stratified for three days at 4 °C before transfer to 20 °C and 100 µmol m-2 s-1 in either long day (LD) conditions (16 h L:8 h D) or short day (SD) conditions (8 h L: 16 h D). Seed trays were moved regularly to prevent any positional effects on plant growth. The time to bolt and the number of rosette leaves at the time of bolting were recorded. Bolting time was measured as the number of days from sowing when the inflorescence stem was approximately 5 mm tall.