Iranian Journal of Seed Research

In order to evaluate the electrical conductivity and seedling growth characteristics of red bean seed grown under drought stress and foliar application of zinc and manganese, a split factorial experiment was conducted in a Randomized Complete Block Design in the field and also laboratory experiment at Shahrekord University in 2011. Factors included three levels of drought stress (irrigation after 50, 70 and 90 mm evaporation from class A pan) as the main plot and three levels of zinc foliar application (with water, 100 and 200 grams per hectare zinc), and three levels of manganese foliar application (with water, 150 and 300 grams per hectare manganese) in a factorial combination as subplot. The results showed that severe drought stress led to decrease of electrical conductivity while the seedling and root length of red bean seed were increased. In the measured characteristics, Mn foliar application had a significant effect on electrical conductivity and root dry weight. In different Mn foliar application treatments, the lowest electrical conductivity was related to control while the maximum seedling dry weight was observed at 150 g Mn foliar application per hectare. Zn foliar application had a significant effect on all the traits measured during this experiment. Based on means comparison, the highest seedling dry weight, shoot, seedling and root length, as well as the lowest electrical conductivity, belonged to the 100 g Zn foliar application per hectare. The highest root dry weight was obtained for 200 g Zn per hectare which no significant difference was observed with 100 g Zn per hectare. According to the results of this experiment, mild stress and foliar application of zinc and manganese led to increasing the quality of the produced seeds. In total, foliar application of zinc and manganese (at the amount of 100 and 300 g ha^-1 respectively) with mild stress (irrigation after 70 mm evaporation from class A pan) are recommended for the production of seeds with high vigor under this region conditions.

Introduction: In addition to dormancy, seeds of Allium hirtifolium have a weak emergence in the field. Among methods for improving the efficiency and emergence of seeds, nutritional priming can be considered for its performance on weak seeds. The presence of micronutrients is one of the factors that may affect the efficiency of the seeds. Therefore, the aim of this study was to investigate the effect of priming with nutrients on optimization of dormancy status, germination, and enhancement of shallot seeds for its conservational, restoration and domestication programs.

Materials and Methods: In order to study effects of nutrients on germination and emergence of Allium hirtifolium, a CRD factorial experiment was conducted with four replications at Seed Science and Technology Lab of Shahrekord University in 2015. Two dormancy breaking treatments (sulfuric acid and sulfuric acid + gibberellic acid) as the first factor and nine nutrition treatments including four levels of ZnSO₄ (5, 10, 50 and 100 mM) and four levels of FeSO₄ (0.5, 1, 1.5 and 2%) versus control were compared on shallot seeds.

Results: The results showed that dormancy breaking treatments, nutrient pretreatment of seeds and their interaction had significant effects on germination percentage, germination rate, time to reach l0% and 50% germination, germination uniformity, seedling length and vigor index I at 1% probability level. Sulfuric acid and FeSO₄1% increased germination versus control. Application of gibberellic acid affected the behavior of iron but did not indicate significant effects for zinc. The concentration of 5 mM ZnSO₄ increased the rate of germination, compared with the control but decreased with higher concentrations. The gibberellic acid did not show any sharp effects on germination rate. Time to reach 50% germination was also affected by FeSO₄ 0.5% and 1% and lower levels of zinc. Application of gibberellic acid did not show any significant impact on the germination time reduction, compared with control and increased T₅₀ in higher concentrations. Although germination traits were rarely affected by gibberellic acid, seedling length and vigor index were positively influenced with GA, and the highest seedling length was achieved at 0.5 and 1% of iron and gibberellic acid.

Conclusion: Seed priming with nutrients can improve germination and plant vigur indices. Different concentrations of iron and zinc showed different impacts on the seeds, which showed interaction with dormancy breaking methods. Although application of gibberellic acid did not have an effective role in increasing germination rate and reducing the time to reach 10% and 50% of germination, it enhanced seedling length and vigor index I, especially for iron.