Temporal physiological and biochemical changes in Hippeastrum vittatum ‘Red Lion’ bulbs stored at different temperatures

Starch and soluble sugar concentrations, α-amylase activity and soluble protein of Hippeastrum vittatum ‘Red Lion’ bulbs were assessed under different storage temperatures and storage periods. Bulbs were stored for 45 days at 20°, 12°, 8° or 4°C. Starch concentration decreased most at 4°C on the 45th day, changing from 29.7% to 10.9% in the exterior scales and from 33.0% to 13.0% in the interior scales. The α-amylase activity in the exterior scales, except at 4° and 8°C, decreased significantly between 0 and 15 days of storage, and then increased significantly from the 15th day until the end of the trial. The soluble sugar concentration increased most at 4°C: in the exterior scales it changed from 54.73 to 153.93 mg•g-1 while in the interior scales it increased from 39.67 to 148.11 mg•g-1. The soluble protein concentration in all treatments peaked on the 30th day at 8°C in the exterior scales (2.15 mg•g-1) and at 12°C in the interior scales (2.17 mg•g-1). Understanding these physiological and biochemical changes in the bulbs of H. vittatum after storage would serve as a reference for bulb dormancy mechanisms in future studies.