Dormancy and enzymatic activity of rice cultivars seeds stored in different environments

Abstract

The objective of this study was to assess the dormancy and the enzymatic activity of seeds of rice cultivars during storage in different environments. After harvesting, the seeds of two rice cultivars (BRS Ourominas and BRSMG Caravera) were dried in the sun, to reach a moisture content around 13%. Then, they were packed in paper and stored in four environments: 5 ± 2 ºC / 70 ± 5% RH, 12 ± 2 ºC / 70 ± 5% RH, 18 ± 2 ºC / 65 ± 5% RH and in a natural condition. Germination and enzymatic activity were assessed at the beginning and at 3, 6, 9 and 12 months of storage. The experiment was conducted in split subplots in a completely randomized design with three replications. The dormancy of seeds stored in the natural environment was exceeded in a shorter time than the dormancy of seeds stored in cold. Catalase and ascorbate peroxidase activity increased during the storage period, the most obviously in storage in natural environment to cultivate BRSMG Caravera. The activity of the enzyme α-amylase decreased during the storage period.