Changes in Tannin, Free Amino Acids, Reducing Sugars, and Starch During Seed Germination of Low and High Tannin Cultivars of Sorghum

Seedling growth and changes in tannin, starch, reducing sugars, and free amino acids were determined during germination of low and high tannin seeds of sorghum. The seedling growth was markedly suppressed in high tannin seeds as compared to low tannin seeds. About 73 and 20% tannins were lost during 120 hr germination in high tannin and low tannin seeds, respectively, Accumulation of reducing sugars, free amino acids, and degradation of starch were considerably low in high tannin seeds as compared to low tannin seeds. It is suggested that tannins are responsible for retarding the seedling growth by decreasing the rate of starch and protein degradation in germinating high tannin seeds.