Effects of salicylic acid and giberellic acid on improvement and prevailing seed deterioration in two sesame (Sesamum indicum) cultivars

Seed deterioration of seed is one of the most important limiting or even hindering factors in germination. The main purpose of this study was to determine the effects of salicylic acid and gibberellic acid hormonal on improvement and prevailing seed deterioration in two sesame cultivars. This studywere carried out at the Department of Agronomy and Plant Breeding Seed Laboratories of College of Agriculture، University of Tehran (Karaj) during 2012-2013. The sesamum cultivars Darab2 and Darab14were the ones studied. The experiment was designed as a factorial of completely randomized design with tree replication. First، germination characteristic measured and then seeds were aged through Controlled deterioration test. Treatments including: two sesamum cultivars; 2 level deterioration (24 and 48 hr) with controlled; and 6 hormonal concentration (25، 50، 100ppm giberellic acid - 25، 50، 100 ppmsalicylic acid) with controlled. The characteristics were measured، including: germination percentage (%)، germination index (GI)، germination speed (GS)، vigor1 and vigor2. Hormonal treatments were applied to both pre-treatmentand post-treatmentin two separate experiments. The results showed that seed deterioration in both level reduced seed trait measured. Darab14 the more resistant to deterioration than darab2. But، with primed hormonal concentration in two conditions pre-treatment and post-treatment، investigated characteristics for two cultivars improvement and prevailing deterioration had taken place. In Darab 2، all concentrations of gibberellic acid in 24 h deterioration level in testing hormonal pre- treatments were better. But، in Darab 14، at both levels deterioration، the hormonal post-treatment showed better results. Our results suggested that salicylic acid 50 ppm، was the most effective treatment in this study.