Abstract: Ratoon rice (RaR) produces a second rice crop from stubble following the primary crop’s harvest. RaR is a resource-efficient and environmentally friendly production system with potential for wider adoption in suitable rice growing environments. Advances in genomic-assisted breeding (GAB) and multi-omics approaches provide opportunities for RaR improvement. Most existing RaR research has primarily focused on management practices, whereas limited progress has been made in developing improved RaR varieties due to the lack of fully focused RaR breeding programs at the global level. Meaningful quantitative trait loci (QTLs) (e.g., qRA2, qRA5, qRAT5), genes (OsCKX1, OsGH3.6, RRA3, and osa-MIR156f), and metabolites (amylose) related to RaR development have been identified. Incorporation of these innovations in practical breeding programs is yet to be ascertained. Overall, this article discusses different breeding, and multi-omics approaches regarding ratooning ability (RA) and grain yield-related traits required for sustainable development of RaR varieties. In addition, the germplasm resources and advantageous plant morpho-physiology related to the performance of RaR is also covered. The integration of conventional breeding, GAB, and multi-omics approaches will facilitate understanding the RA and development of high-yielding RaR varieties with improved agronomic performance and adaptability. High-yielding RaR varieties are beneficial for rice growers and other stakeholders by promoting large-scale commercial cultivation and contributing to the expansion of rice cultivation areas, ultimately leading to enhanced food security, environmental sustainability, and economic benefits.

Key words: rice, ratooning ability, molecular breeding, multi-omics approach, sustainable agriculture