Changes in Alpha-Amylase Activity of Germinating Rice Grains Exposed to Different Temperatures and Oxidation-Reduction Potentials

Abstract

The α-amylase activity of the germinating grains increased with the decrease of the oxidation-reduction potential (redox potential) at 18 °C. At 30 °C, the α-amylase activity was not affected by the changes in the redox potential. At 18 °C, in most of the culti-vars the increase of the α-amylase activity continued after the imbibition of the grains towards the final sampling stage, but in some of the cultivars the maximum activity was reached at earlier grain incubation stages and then decreased. At 30 °C, in most of the cultivars the maxlmum activity was attained at earller incubation stages and then decreased, but in some of them the activity continued to increase until the final salnpling stage. At 18 °C, the α-amylase activity was not correlated with the root and shoot growth. The α-amylase activity was lower in the Japonica than in the Irdica and Javanica cultivars.