Figure 1. Characterization of the osbt1 mutant.

(a,e) Appearance of mature seeds of wild-type (WT) (a) and osbt1 (e); (b,f) Cross-sections of mature seeds of WT (b) and osbt1 (f); (c,g) SEM analysis of the periphery area of mature endosperm of WT (c) and osbt1 (g). The periphery areas shown are indicated as blue squares in (b,f); (d,h) SEM analysis of the central area of mature endosperm of WT (d) and osbt1 (h). The central areas shown are indicated as red squares in (b,f); Scale bars: 1 mm in (a,b,e,f); 20 μm in (c,d,g,h); (i–l) Quantification of WT and osbt1 seed size and grain weight including grain length (i), grain width (j), grain thickness (k) and 1000-grain weight (l). Data are given as means ± SD from three replicates. Statistical comparisons were performed using Student’s t-test; all data were compared with WT (*P < 0.05, **P < 0.01).