Integrating Frontier Technologies to Achieve Semi-Dwarfism in Rice: Highlights on Genome Editing and Artificial Intelligence

Rice is an integral component of global food security, and the introduction of semi-dwarf varieties has been a significant contributor to increased yields since the Green Revolution. The review article summarizes the genetic, molecular, and agronomic aspects underlying semi-dwarfism in rice, focusing on the Semi-Dwarf1 (SD1) gene that encodes a gibberellin 20-oxidase and on additional genes involved in gibberellin and brassinosteroid pathways. Subsequent genetic mapping, gene cloning, advanced molecular breeding, and AI-guided precision techniques have revealed that mutations in additional genes, beyond the SD1 allele, also contribute to dwarfism in rice. The review also covers traditional and molecular breeding methods, marker development, and CRISPR-mediated genome editing for targeted mutation to achieve semi dwarfism in rice. CRISPR offers high precision and the potential to generate transgene-free semi-dwarf lines, but challenges including off-target effects, mosaicism, and regulatory hurdles remain important limitations. In parallel, artificial intelligence and machine learning approaches exacerbate the process of high-throughput phenotyping, genomic prediction, and candidate-gene prioritization. However, model transparency and integration of genotype-by-environment data are still incomplete. Even if semi-dwarfism in rice contributes to substantial increases in yield, some difficulties, for instance, genetic uniformity and potential trade-offs with other agronomic traits, remain important challenges due to the widespread reliance on the SD1 gene. Finally, the review highlights the future prospects for integrating alternative semi-dwarf genes with genome editing and AI-assisted selection, which offers a practical route to more genetically diverse, lodging-resistant rice varieties with stable yield performance, thereby contributing to sustainable rice production and global food security.