Fig. 1.

Map-based cloning of the gene controlling embryo size.

A. Representative images of grains and embryos from the lines described in Table 1 are shown. Upper row = dry, mature grains. Lower row = excised embryos. The scale bars are 3 mm. B. Relative embryo weight and β-amylase activity were determined for selected lines shown in Table 1. The values for relative embryo weight are the means ± SE for 3 to 14 samples, each sample consisting of 10 embryos/grains. The samples were from 3 to 8 plants, as shown in Table 1. Data were statistically analysed using Tukey's HSD test after one-way ANOVA and values with significance levels ≤0.05 are indicated by letters (a, b, c). The values for β-amylase activity are the means ± SE for three plants. One grain from the middle of the ear was assayed per plant. All assays were triplicated. C. The gene controlling embryo size maps to a region on chromosome arm 5HL. The two markers/genes flanking this region are shown in bold. The LYS3/PBF gene controlling embryo size was identified as HORVU5Hr1G048700. Gene names are abbreviated: xxxx = HORVU5Hr1G04xxxx. D. An alignment of PBF amino acid sequences showing the positions of the DOF domain and the SNP mutations. (Risø18 lacks PBF and is, therefore, not shown).