Genetic and Environmental Effects on Phenolic Composition and Agronomic Performacne in Black Sorghum (Sorghum bicolor L.) Hybrids
A healthy diet requires a shift from the consumption of highly refined and processed foods with low nutritional value and towards whole grain food that have increased levels of antioxidants and phenolic compounds. Certain specialty sorghum genotypes have been identified as potential whole grain foods that have high levels of desired chemical compounds. Specifically, sorghums with a black pericarp are excellent sources of antioxidant compounds, including the unique compound 3-deoxyanthocyanin (3-DOA). Although extensive work has been performed on the chemistry and food properties of black sorghum inbreds, little research has been done studying the grain phenolic composition and agronomic performance of black sorghum hybrids in production environments. The goal of this study was to evaluate black sorghum hybrids with differing genetic backgrounds for grain phenolic composition and agronomic performance across multiple environments and identify the best lines for producing these hybrids. Results from this study confirm that sorghums with a black pericarp contain elevated levels of phenols, tannins and 3-DOA. Concentrations of these beneficial compounds were many times the concentration levels seen in traditional grain hybrids. Grain yields of black sorghum hybrids averaged 36% below commercial hybrids in this study. Lower grain yields could be due to reduced heterosis in black sorghum hybrids and other unknown factors associated with the black phenotype. From this study, the Texas AgriLife Sorghum Breeding Program has developed two elite black sorghum lines for release as the first publicly available black pericarp seed parents. These newly developed seed parents, proposed for release as Tx3363 and Tx3364, allow for the creation of the first temperately adapted black seeded grain hybrid. These hybrids help address the growing demand for products that are healthy, and provide natural and stable antioxidant compounds for a growing health food industry.
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