ASHS 2025 Conference

Carrots are one of the most popular vegetables, valued for both their culinary uses and health benefits. While carrot breeders have primarily focused on enhancing appearance to meet consumer expectations, flavor is also an important factor. Sugars, which are key to carrot flavor, are the focus of this project. Carrots accumulate two main types of free sugar-reducing sugars (glucose and fructose) and non-reducing sugars (sucrose). Carrots with high percentage of reducing sugar tend to have sweeter, less harsh and more preferred flavor. The balance between sucrose and reducing sugars is controlled by a dominant gene called Rs, where heterozygous plants have a higher proportion of reducing sugars. In this study, we conducted a genome-wide association study (GWAS) using a diverse set of carrot accessions grown over five years to identify SNP markers linked to sugar composition in carrots. The enzyme acid-soluble invertase isozyme II, which breaks down sucrose into glucose and fructose, was identified as the most significant candidate gene. To further validate this gene’s involvement in the Rs locus, we are using genome editing techniques. Details of this genome editing work will be presented.