Genotypic diversity and genome-wide association study of gelatinization and retrogradation properties of potato starch

Potato starch gelatinization and retrogradation properties underpin functional performance in food and industrial applications, yet their genetic architecture in potato remains incompletely resolved. We profiled differential scanning calorimetry (DSC) traits for gelatinization and retrogradation across two environments in a diverse potato panel. Wide genotypic variation was observed, with highly significant genotype, environment, and genotype-by-environment (G × E) effects. Gelatinization temperatures were strongly correlated with each other and positively associated with the retrogradation percentage (R%). A genome-wide association study (GWAS) identified loci near ADP-glucose pyrophosphorylase large subunit ( AGPL ) on chromosome 1 for onset gelatinization temperature, glucan water dikinase ( GWD ) on chromosome 5) for conclusion gelatinization temperature, and of ADP-glucose pyrophosphorylase small subunit ( AGPS ) and starch branching enzyme ( SBE ) on chromosome 7 for the retrogradation peak temperature. These findings implicate that carbon flux, starch phosphorylation, and branching are key factors determining the starch functional properties. Together, the results provide a foundation for targeted breeding strategies aimed at improving starch quality for both industrial and food applications. • Wide variation in potato starch gelatinization and retrogradation traits observed. • GWAS identified key loci in AGPL , GWD , AGPS , and SBE genes. • Loci near AGPL1 and GWD govern starch gelatinization properties. • AGPS1 and SBE1 influence retrogradation and structural reassembly. • It implies amylopectin branching and phosphorylation affect crystalline organization.