Effects of Gibberellin, Salicylic Acid, and Ascorbic Acid on Improvement of Germination Characteristics of Deteriorated Seeds of Brassica Napus

One of the most important oilseed plants in Iran is rapeseed. Seed quality is affected by deterioration and aging during storage. The purpose of this study was to evaluate the roles of various chemicals on the recovery of germination characteristics in deteriorated seeds of rapeseed. In this study, one commercial Brassica napus cultivar (okapi) was used. This experiment had two parts. In the first part, seeds with different moisture contents (5, 9, 13, 17%) were stored in incubators set at five temperatures (5, 15, 25, 35, 45ºC). After 90 days, germination was conducted for these 20 storage conditions. In the second part, deteriorated seeds with high germination percentage (74%), medium germination percentage (47%) and low germination percentage (5%) resulted from following treatments: 9/35, 13/25 and 17/25 (moisture content/ storage temperature), respectively, were treated with various chemicals. These chemicals were gibberellic acid, salicylic acid and ascorbic acid in four levels including control, 25, 50 and 100 ppm. A factorial experiment was conducted in a completely randomized design with four replications. Analysis of variance showed that the main effects of deterioration, chemicals concentrations and their interactions were significant for all measured traits. The best treatment was ascorbic acid with concentration of 100 ppm which increased germination percentage and percentage of normal seedling by 29 and 48%, respectively.