Paraffin sections of XS and lg5. (A) Spikelet glume just before heading; bar = 3.4 mm. (B) Central parts of spikelet hulls of the line in (A); bar = 320 μm. (C) Magnified views of the boxed areas of (B); bar = 60 μm. (D–F) Total length, cell number, and cell length in the outer parenchyma layer of the spikelet hulls. (G) Comparison of leaf lamina joint; bar = 5 mm. (H) Magnified views of the boxed areas of (G); bar = 50 μm. (I,J) Cell length and cell width of the leaf lamina joint. Data were presented as means ± SD. * and ** indicate p < 0.05 and p < 0.01, respectively, according to Student’s t-test.