Genetic variability for cyanogen and trypsin inhibitor contents in sorghum (Sorghum bicolor (L.) Moench)

Abstract

Sorghum is a staple food in the arid and semi-arid tropics, and is an important animal and bird feed in some developed countries. Very limited reports are available on anti-nutritional factors in sorghum. Grains of 200 sorghum genotypes including adapted cultivars and parental lines were characterized for the levels of cyanogens and trypsin inhibitor. Significant variation was observed for cyanogens (14.2-173.6 ppm) and trypsin inhibitor (1.6-12.8 TIU). The popular cultivars and parental lines had only moderate levels of these anti-nutritional factors. Selected 33 genotypes including the ones with extreme values were reanalyzed and the results were confirmed with high correlation for cyanogens (r = 0.96, p < 0.001), while in case of trypsin inhibitor a moderate correlation (r = 0.41, p = 0.04) was obtained. The results show that presence of cyanogens and trypsin inhibitors in sorghum do not pose a serious challenge to the nutritional quality as perceived previously in the developed world.