Supplementary Fig. 1s. Distribution of root length of two F2populations. The root lengths were measured 7 d after germination in germination boxes. Left, root length distribution of 99 F2 individuals derived from a cross between common wheat cultivar Louis and synthetic wheat accession TA4152-71 (TA). Right, root length distribution of 110 F2 individuals derived from a cross between common wheat cultivar Opata and TA. The numbers in the x axes indicate root length in cm, and the numbers in the y axes indicate the numbers of the F2 individuals with the same root length.