Fig. 1.

Days to heading (DTH) for Yuikogane and Shinanotsubuhime under different day-length conditions and frequency distributions of DTH in F₂ population. A: The phenotype of Yuikogane (left) and Shinanotsubuhime (right) 85 days after sowing under ND conditions. The scale bars are 10 cm. B: DTH for Yuikogane and Shinanotsubuhime under natural day-length (ND) conditions in a field, long-day (LD) and short-day conditions (SD) in a growth cabinet. Error bars represent the standard error (n ≥ 10). C: DTH was investigated under natural day-length conditions in an F₂ population (n = 381) of a cross between Shinanotsubuhime and Yuikogane. The mean values for DTH were 80.7 days (Yuikogane) and 91.6 days (Shinanotsubuhime) as indicated by white and black arrowheads, respectively. Red boxes indicate Y-bulk, S-bulk and L-bulk respectively. These bulk samples applied to QTL-seq.