Maximum germination percentage achieves immediately after harvesting and gradually decreases with storage time. Aging is one of the key factors in plant yield loss especially in vegetables. Seed aging is the main problem of seed storage. Application of accelerated aging treatment is used to assess seed vigor and quality. Seed priming enhances seed germination performance after aging. An experiment was conduct in order to investigate the activity of catalase and ascorbate peroxidase during accelerated aging and repair during priming treatment of sorghum seeds. In order to improve germination characteristics in aged seeds with seed priming. Our result showed that seed priming treatments significantly (p≤ 0.01) affected, germination percentage, germination index and means time to germination after aging (0, 3 and 6 days). Increasing aging duration resulted higher reduction in germination characteristics. Priming with gibberelic acid (GA), salicylic acid (SA) and ascorbic acid (ASC) increased germination characteristics of seed aged. The highest germination percentage, germination index, normal seedling percentage and enzyme activity were achieved in control conditions (0 day of aging). Antioxidant activity of aged seeds increased after seed priming.
Seed priming with gibberellin (GA) enhances seed germination performance; but the quality of primed seeds in aging condition often reduces more than non-primed seeds. An experiment was conducted to evaluate the effect(s) of heat shock treatments on germination characteristics and enzyme activity of primed mountain rye (Secale montanum) seeds with gibberellin under accelerated aging. Heat shock treatments, can substantially decrease the speed of quality reduction of mountain rye (Secale montanum) primed seeds. In primed seeds with gibberellin, which has non-aged, the highest germination percentage (GP) and normal seedling percentage (NSP) was attained from heat shock treatment at 35°C for 3 h, also after 3 days aging, it was attained from heat shock treatment at 35°C for 3 h. After 3 days of aging the highest germination index (GI) was attained from unprimed seeds, but no significant difference with heat shock treatment at 35°C for 3 h. The minimum means time germination (MTG) was in heat shock treatment at 30°C for 3 h in non-aged seeds. After 3 days of aging, heat shock treatment reduce MTG as compared to the primed seeds. Heat shock treatment at 35°C for 3 h increased seed vigor index (SVI) as compared to the unprimed and primed seed in non-aged seeds and after 3 days aging. Seedling length (SL) increases with heat shock treatment at 30°C for 4 h in non-aged seeds as compared to the primed and unprimed seeds, but after 3 days of aging heat shock treatment except at 35°C for 3 h and 40°C for 4 h reduced SL as compared to the primed and unprimed seeds. Also, heat shock treatments increase some antioxidant enzymes [Catalase (CAT), Ascorbat peroxidase (APX)].