Multifloret spikelet improves rice yield.

Abstract

The typical rice (Oryza sativa) spikelet contains a single fertile floret and produces only one grain; by contrast, Brachypodium distachyon spikelets contain multiple fertile florets and produce several grains. To increase yield, rice breeders have traditionally focused on panicle morphology (branch number and length, spikelet density), but have not considered the number of florets in each spikelet. Production of rice spikelets with more florets could further increase the number of grains per panicle. Here, we describe two novel approaches - altering meristem determinacy and restoring lateral floret formation - for breeding rice cultivars with a multifloret spikelet, thereby increasing the number of grains per panicle and potentially improving yield.