Comparative assessment of grain quality in tannin versus non-tannin sorghums in the sorghum association panel

Background and ObjectivesThe presence of antinutritional compounds such as tannins reduce the nutritional benefits in sorghum. Hence, the major objective was to evaluate the differences in grain quality and physical parameters in 254 tannin and non-tannin accessions in a diverse set of sorghum association panel. FindingsWide variability was noticed for total protein (11%-19%) and protein digestibility (13%-78%). Tannin content recorded a significant negative relationship (R-2 = 0.65, p < .001) with protein digestibility, indicating strong impact of tannins on protein digestibility in sorghum accessions with a pigmented testa. Non-tannin accessions exhibited higher protein content, protein digestibility, kernel hardness, kernel weight and diameter, and lower phenolics compared to tannin accessions. Among the genetic races, Durra had the highest protein digestibility and Caudatum had the highest kernel weight than other races. In accessions with tannin, red grains had the highest tannin content and lowest protein digestibility than other colored grains. ConclusionsThe study revealed accessions with high protein digestibility of around 71% in both non-tannin and tannin groups. A tannin containing accession SC1056 had the highest protein digestibility (78%) coupled with high kernel hardness. Significance and NoveltyAccessions with above-average protein digestibility, either with or without tannins could be ideal donors for breeding for improved grain quality in sorghum.