Engineering high-frequency apomixis with normal seed production in hybrid rice

Summary: Clonal reproduction through seeds, also termed apomixis, has the potential to revolutionize agriculture by allowing hybrid crops to be clonally propagated. Although apomixis has been introduced into rice through de novo engineering in recent years, the poor fertility and low-frequency clonal reproduction of synthetic apomicts hinder the application of apomixis in crop breeding. Here, in elite hybrid rice, we generated many apomicts, which produced clonal progeny with frequencies of > 95.0% and had high even normal fertility through combining enhanced rice BABYBOOM1 (BBM1)-induced parthenogenesis with the simultaneous inactivation of PAIR1, REC8, and OSD1. These synthetic apomicts maintained the agronomic traits of the elite hybrid rice. Our results indicate that fertility-normal hybrids with high penetrance of apomixis can be generated in rice, thereby laying an important foundation for the application of synthetic apomixis in crop breeding.