Fig. 1. Maize inflorescence development. (A) Different meristem types in maize. The inflorescence meristem (IM) forms spikelet pair meristems (SPM) which form two spikelet meristems (SM), each of which forms two floral meristems (FM). Tassels also form branch meristems (BM) at the base. (B,C) Schematic of a spikelet pair. Each spikelet contains two glumes and two florets. The mature floret comprises the lemma, a palea, three lodicules (one of which is rudimentary and not shown), three stamens and a pistil. The pistil aborts in male spikelets (B). All stamens and the lower floret abort in female spikelets (C). (D) Male inflorescence. The basal branches on the tassel form indeterminate BMs, which give rise to SPMs in a distichous pattern. SPMs give rise to two SMs that are side by side. Each SM forms two floral meristems (FM). (E) Female inflorescence development proceeds similarly to that of male inflorescence development, only BMs are suppressed in the ear. The boxed area contains six spikelets. In each spikelet, the upper FM and outer glume are visible. The lower FM and inner glume are obscured.
