Decoding heterosis in rice: from classical theories to modern omics insights

Area of Science:

• Plant genetics and breeding
• Molecular biology
• Agricultural science

Background:

• Heterosis, or hybrid vigor, is key to rice yield improvements and global food security.
• A unified molecular theory explaining heterosis is still lacking.
• Understanding heterosis drivers is critical for advanced rice breeding.

Purpose of the Study:

• To review recent advances in rice heterosis research, focusing on genetic and multi-omics approaches.
• To integrate evidence supporting various heterosis hypotheses (dominance, overdominance, epistasis).
• To highlight the role of AI in next-generation hybrid rice breeding.

Main Methods:

• Consolidation of recent genetic and multi-omics research findings.
• Analysis of genomic, transcriptomic, epigenetic, and metabolomic data.
• Review of evidence supporting different heterosis theories.

Main Results:

• Heterosis is a complex phenomenon driven by synergistic interactions across multiple omics levels.
• Non-additive gene expression and metabolic changes are crucial for hybrid performance.
• Evidence supports dominance, overdominance, and epistasis as contributing factors.

Conclusions:

• Heterosis is not explained by a single mechanism but by complex, multi-layered interactions.
• Future research should focus on dynamic pathways, including energy metabolism, for mechanistic understanding.
• Advancing heterosis research will accelerate the development of high-yielding, resilient hybrid rice.