Figure 2.

A generalized diagram of awn development in rice. From heading to a few weeks before anthesis, awned and awnless spikelets show similar growth. During the anthesis, reproductive organs differentiate and awned spikelets show higher growth than awnless spikelets. During the milk stage, the grain starts to develop, and the awn elongates in the awned spikelet, whereas the awnless spikelet forms a round tip. During the dough and maturity stages, the awn photosynthetic activity drops, the spikelet decreases in volume, and the awned plant provides a longer and larger seed than the awnless spikelet. EG, empty glume; LE, lemma; OV, ovary; PA, palea; PE, pedicel; PI, pistil; RG, rudimentary glume; ST, stigma.