FIGURE 1.

Spatial distribution and development of spikelets on the rachis of the rice panicle. (A) The spikelets are termed as terminal or lateral depending upon whether these are derived from the modification of the axis, termed as terminal spikelets, or the lateral branches, termed as lateral spikelets. The lateral branches may be primary, secondary, or tertiary in nature depending upon whether these are originated from the rachis, primary branches, or secondary branches, respectively. (B) Pictorial representation of progression of anthesis of the spikelets on the rice panicle, which is an acropetal event with spikelet groups I, II, III, IV, V, VI, and VII reaching anthesis progressively on the first, second, third, fourth, fifth, sixth, and seventh days (Mohapatra et al., 1993). Groups I to III represent the apical (superior) spikelets, while groups V to VII represent the basal (inferior) spikelets. Panel 2A is reproduced with the permission of the author (Xing and Zhang, 2010). Panel 2B is reproduced with the permission of the publisher (Mohapatra et al., 1993).