Revisiting the Molecular Roadmap for Sugar Crops: Genome Reading, Trait Writing and Variety Redesigning.

Sugar crops, including but not limited to sugarcane, sugar beet, sweet sorghum and stevia, are major sources of sugar production in the world. However, conventional breeding approaches, limited by long breeding cycles, low efficiency and restricted capacity to improve complex traits in sugar crops, are increasingly insufficient to address the challenges posed by climate change and the demands of sustainable agriculture. This review systematically summarizes recent advances in biotechnology and molecular breeding that have transformed sugar crop improvement. Recently, high-throughput sequencing technologies have generated extensive multi-omics resources. Concurrently, numerous functional genes and genetic elements with substantial breeding potential have been identified and cloned, offering precise targets for the key agronomic traits in sugar crops. Marker-assisted selection has been successfully implemented to enhance disease resistance, while genomic selection has demonstrated well for the evaluation and selection of complex quantitative traits. Importantly, genetic transformation systems have enabled precise manipulation of target genes and facilitated the creation of novel germplasm. In the future, the integration of multi-omics data, artificial intelligence, high-throughput phenotyping and precision genome editing into an intelligent breeding framework will be essential for achieving breeding by design and developing climate-adaptive and smart cultivars. Ultimately, these technological innovations will expand the role of sugar crops beyond traditional sugar production, positioning them as a central platform for sustainable biomanufacturing and providing critical support for global sugar security, energy transition and the development of the bioeconomy.