Intergeneric hybridization and domestication breeding is an efficient means for utilizing wild rice germplasm resources. In this study, we constructed gap-less genome assemblies for two CC, two BBCC and one CCDD wild rices to explore the role of the C subgenome in rice diversification. Furthermore, we assembled the genome of a cultivated rice (AA) and further developed A/C hybrids with enhanced resistance to BPH using an efficient hybrid embryo rescue system.