Characterization of Agronomic Traits and Composition of Antioxidant Compounds in Sweet Sorghum (Sorghum bicolor L. Moench) Germplasms

Sweet sorghum (Sorghum bicolor L. Moench) is one of the most important crops for bioethanol production and the provision of antioxidant compounds for human health. In this study, we investigated the 8 agronomic traits of 153 sweet sorghum germplasms, which demonstrated a variety of phenotypes. In particular, nine sweet sorghum germplasms exhibited a sugar content exceeding 20 Brix. Based on agronomic characteristics, we selected eight elite sweet sorghum germplasms that showed highperformance agronomic and growth characteristics such as tall height, large panicle size with short height, high sugar content, and seed-specific characteristics. The selected germplasms also showed significant differential amount of 3 antioxidant compounds of 3-deoxyanthocyanins, flavonoids, and tannins. SS113 contained the highest levels of total 3-deoxyanthocyanins with apigeninidin contents 3-9 fold higher than that of other germplasms, while SS129 had a white seed coat with the highest recorded total flavonoid level (7.52 mg/g) but no detectable 3-deoxyanthocyanins compounds. The characterization of the traits and compounds will be useful for basic research into the selection of suitable cultivars in the breeding of sweet sorghum.