Enrichment of phytoglycogen in sweet corn kernels through genomics-assisted selection

Higher phytoglycogen in Su1-based sweetcorn kernels have created a niche market in Europe and Americas due to its distinct aroma, flavour and tenderness as well as plump and juicy texture over Shrunken2 (Sh2)-based sweetcorn. Unavailability of diverse Su1-based inbreds poses challenge for Su1-based hybrid development. Here, we introgressed mutant Su1 gene into four elite Sh2-based parental lines of two Sh2-based sweetcorn hybrids (PSSC-1 and PSSC-2) using molecular breeding in two backcrosses. Su1-based (SuDel36) and Sh2-based (SNP_AG1) markers were successfully used for foreground selection in backcross generations, that followed Mendelian segregation, although segregation distortion was observed in a few cases. More than 94% recurrent parent genome was recovered using SSR markers. Su1-based inbreds possessed significantly higher phytoglycogen (24.3%) over recurrent parents (5.6%). Across environments, Su1-based reconstituted hybrids also possessed higher phytoglycogen (25.8%) compared to original hybrids (5.5%). The Su1-based inbreds and hybrids possessed 14.4% and 13.9% sucrose, respectively. These inbreds and hybrids resembled their original versions for various agronomic traits. These newly developed Su1-based sweetcorn hybrids possess great potential in export markets, besides serving as a rich source of phytoglycogen in cosmetics, pharmaceuticals and nutraceuticals industries. This is the first report on development of phytoglycogen-enriched Su1-based sweetcorn hybrids using accelerated breeding. This is likely to promote broader industrial applications of phytoglycogen, thereby unveiling the underexplored potential of Su1-based sweet corn.