Iranian Journal of Seed Research

Extended abstract
Introduction: Seed deterioration is a physiological phenomenon that affects all germination, biochemical, cytological, and growth characteristics of plants. So it is necessary to use seed vigor enhancement methods to resolve these problems. One of these methods is the application of seed priming techniques to reduce deterioration effects. Therefore, the present study aimed to investigate the effect of different pre-treatments by using Nano-zinc, ascorbic acid, humic acid, gibberellin and KNO₃ on germination indices and chromosomal aberration of aged onion seeds.
Material and Methods: This experiment was performed as factorial based on a completely randomized design with 3 replications (100 seeds per replicate) in the faculty of agriculture at Urmia University. The first factor was the level of aging at 4 levels (control, 12h, 24h, and 48h) and the second factor was seed pre-treatments at 6 levels (control, Nano-zinc (30 mg), ascorbic acid (100 mg), humic acid (150 mg), gibberellin (200 mg/l) and KNO₃ (0.1%). Given that the germination was not similar at different levels of aging, the seeds were germinated at control and 12h of aging after 6 days, at 24 and 48h of aging after 8 and 9 days, respectively. Hence, germination percentage, germination rate, normal seedling, mean germination time, and seed vigor were evaluated after the mentioned times. Chromosomal aberrations were also examined.
Results and Discussion: The results showed that the interaction effect of aging and seed pre-treatments on germination indices were significant at %1 probability level. By increasing the period of aging, all germination characters decreased significantly. The highest germination percentage (80%, 70%, 50%) and germination rate (5.350, 3. 316, 1.525 seed/day) were obtained by using Nano-zinc At 12h, 24h and 48h ageing levels. Nano-zinc and gibberellin had the highest effect on seedling vigor and normal seedlings. Seedling vigor increased significantly by using Nano-zinc and gibberellin at 12h (1133, 933.9), 24h (742.9, 692), and 48h (369.9, 323.3). The chromosomal aberration was reduced by using pre-treatment.
Conclusion: In this study, the most effective pre-treatments to improve germination characteristics and reduce chromosomal aberrations were gibberellin (200 mg/l) and Nano-zinc (30 mg). Therefore, it can be stated that the use of Nano-zinc and gibberellin as seed pre-treatments can significantly reduce the effects of deterioration on onion seeds.

Highlights:
1- Nano-Zinc and gibberellin were the most effective priming treatments on seed germination and growth characteristics of the aged onion seeds.
2- Priming treatment reduced the percentage of chromosomal aberration in the onion and the highest effect was obtained using Nano-zinc and gibberellin.

Extended abstract
Introduction: Small size of Satureja (Satureja hortensis L.) seed causes many problems in mechanized cultivation and its seed consumption is increased significantly.  The approach discussed in the present study is the seed coating of Satureja by several matters and selecting the suitable method as well as investigation of adding hormonal and nutritional substances to the selected coating material for better emergence and the elimination of problem arise as a result of coating.
Materials and Methods: Purified Satureja seeds (97%) were prepared and poured into the coating machine at a specified amount. First, 1% solution of benomyl fungicide was sprayed on the seeds. Then some coating powder was sprayed on the spinning wet seeds inside the machine. Then some of the adhesive solution was sprayed on it and again the coating powder was added and this was repeated several times to create a suitable form for the coated seeds. This was repeated using different materials and among these coatings powder, vermiculite and perlite provided better coating on Satureja seed. Then, different materials including gibberellin, BAP, cytokinin, thiourea (CH₄N₂S) and potassium nitrate (KNO₃), phosphorus from H₂PO₄ source and manganese sulfate (MnSO₄) were used to the emergence of the enlarged seeds and also, the emergence of these seeds were evaluated in the greenhouse.
Results: Initial results showed that vermiculite and perlite provided better cover for Satureja compared with the other coating materials. Investigating the emergence of perlite-coated seeds in the greenhouse showed that gibberellin (all concentrations) and kinetin (500 mg/l) present in the seed coat improved the Satureja seed emergence under greenhouse condition. Also, it was found that Thiourea (700 and 7000 mg/l), potassium nitrate (7, 70, 700 mg/l), phosphorous (9 kg/100 kg seed) and manganese sulphate (2 and 4 mg/l) present in the coat significantly increased the Satureja seed emergence and led to improved seedling growth.
Conclusion: Perlite for the purpose of seed pelleting of Satureja showed good results and the use of gibberellin (at all concentrations) and quintine (500 mg/l) in the seed pelleting improved germination of pelleted Satureja seed.
 

Highlights:
1- Technical knowledge of Satureja seed pelleting was obtained.
2- The suitable material to improve the emergence of pelleted Satureja seed was introduced.