Agro-Morphological and Biochemical Characterization of Korean Sorghum (Sorghum bicolor (L.) Moench) Landraces

Abstract

Sorghum landraces are essential for developing cultivars with improved properties, such as disease tolerance, yield and metabolite content. In this study, 139 genotypes (136 Korean sorghum landraces and 3 control cultivars) collected from various provinces were investigated using eleven agronomical and five biochemical traits. The landraces showed little variation in their qualitative agronomical traits. In contrast, quantitative agronomical and biochemical traits differed significantly among the landraces. It was discovered that 16 landraces matured ahead of all control cultivars. Furthermore, 26 landraces had significantly higher thousand seed weights (TSWs) than two of the control cultivars, including Nampungchal (30.63 g) and Sodamchal (30.53 g), whereas only 1 landrace had a significantly higher TSW than the other control cultivar, Wheatland (37.93 g) (p < 0.05). The levels of total tannin content (TTC), total phenolic content (TPC), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) radical cation scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) were in the ranges of 0.12–428.95 mg CE/g, 1.17–10.23 mg GAE/g, 1.64–67.60 mg TE/g, 0.48–31.99 mg AAE/g and 0.63–21.56 mg AAE/g, respectively, and were all affected by collection area, seed weight and seed color. Landraces from northern provinces were discovered to have higher metabolite contents. Furthermore, large seeds had higher TTC and TPC levels as well as DPPH, ABTS and FRAP activities than medium and small seeds, except for the TTC and FRAP, which were significantly different. In terms of seed color, white seeds had significantly lower metabolite contents and antioxidant activities and were notable in principal component analysis. Correlation analysis revealed positive and significant associations between biochemical traits, as well as between panicle-related agronomic traits. In general, the landraces with superior characteristics could be ideal candidates for sorghum breeding programs.