Mutation breeding strategies and advances for sugarcane (Saccharum spp.) improvement

Abtracts: Sugarcane (Saccharum spp.) is a globally and strategically important source of sugar and bioenergy. Its highly polyploid, complex genome and narrow genetic variability, however, hinder its genetic improvement and renders as time consuming its development of superior cultivars. Induced mutagenesis, fortunately, has emerged as a powerful approach to generate novel genetic variation, opening new avenues to enhance productivity, stress resilience, and resource use efficiency. This review examines random and targeted mutagenesis in sugarcane improvement. Random methods, such as gamma rays, ion beams, ethyl methanesulfonate (EMS), and sodium azide (SA), have successfully produced variants with improved resistance to biotic and abiotic stresses and enhanced yield. Meanwhile, advanced genome-editing tools such as Transcription Activator-Like Effector Nucleases (TALENs) and Clustered Regularly Interspaced Short Palindromic Repeats associated with Cas (CRISPR/Cas) systems enable precise genetic modifications in sugarcane. CRISPR/Cas-based approaches have shown promise by targeting multiple allele copies simultaneously, facilitating variety development with reduced lignin content, improved saccharification efficiency, and herbicide tolerance. The review also highlights the underexplored potential of additional mutagens that could further broaden sugarcane´s genetic base. Costa Rican breeding programs are already integrating these technologies to accelerate varieties development. Overall, advances in mutagenesis and genome editing not only promise to bolster sustainability and economic viability of sugarcane production, but also contribute globally to strengthen food and energy security in the face of climate change and increasing resource demand. Key message: Induced mutagenesis and biotechnological tools expands the narrow genetic base of sugarcane, overcoming limitations of conventional breeding.