Genetic and functional mechanisms of yield-related genes in rice

Rice yield potentiality has been enhanced much after incorporating semi-dwarf trait in rice, which has led to the Green Revolution worldwide, but afterward, yield potentiality has increased marginally. To keep pace with increasing food grain demand due to increasing population, rice production needs to be enhanced even though available land, water, and other natural resources are limited. Thus, the only option is to improve intrinsic yield potentiality. Generally, rice yield is determined by different direct and indirect source and sink size-related components such as grain number per panicle, weight of grains, number of tillers, panicle architecture, heading date, etc. During the last two decades, QTL mapping and map-based cloning have identified several QTLs and genes controlling intrinsic and extrinsic factors of yield, followed by proper validation for their yield-enhancing ability in diverse rice backgrounds of indica and japonica subspecies. Because of the character's complexity, identifying favorable alleles of these genes, followed by gene pyramiding is the main strategy for high-yielding variety development. Any update regarding the molecular mechanism, gene functions and gene-to-gene interaction will assist a breeder to move a step ahead toward yield improvement. This review summarizes the recent progress of these genes and their contributions to yield and this information will further advance and facilitate rice breeding with more precision and efficiency.