Improving the Food Quality of Sorghum: Utilizing Functional Genomics to Identify Novel Starch Phenotypes in EMS Sorghum Mutants.

Sorghum bicolor is the main food source for 500 million people around the world.  Sorghum is a highly versatile food source that is widely utilized in marginal environments. The food quality of sorghum, however, is relatively poor, and research and innovation in the area of sorghum is severely lacking. This research focused on identifying mutants with the potential to produce a higher food quality through modification of the starch properties. Eleven different lines of mutant sorghum were analyzed to determine if any of the lines display characteristics that deviate from the control sorghum line, Tx623. Three different characteristics of the starch, amylose content, retrogradation profiles, and gelatinization profiles, were analyzed. Two different lines displayed significantly higher levels of amylose than Tx623. Both of these lines had mutations in the 1,4-alpha-glucan-branching enzyme.  These two lines also displayed increased retrogradation and decreased enthalpy of gelatinization and temperature of gelatinization.  These novel starch phenotypes of sorghum could improve the utilization of the grain in food and beverage applications.