Scanning electron microscopy analysis of wild-type and osmads34 inflorescence and spikelet primordia. A to E, The wild type. F to J, osmads34-1. K to O, osmads34-2. A, F, and K, Early stage (In3 stage) of primary branch formation. Stars mark the primary branch primordia. B, G, and L, Elongation of primary branches (In4 stage). Stars mark the primary branches. C, H, and M, Differentiation of higher order branches in the wild type (In5 stage), but the rachis meristem of the mutant loses its activity. Stars mark the primary branches, arrowheads mark the secondary branches, and black arrows indicate the elongated hair-like structures. D, I, and N, Young spikelet meristems at stage Sp6, when stamen primordia merge. E, J, and O, Young spikelet meristems at stage Sp8. ca, Carpel; le, lemma; lsl, lemma/leaf-like sterile lemma; pa, palea; rg, rudimentary glume; sl, sterile lemma; st, stamen. Bars = 50 μm.