Effects of Silica and Silver Nanoparticles on Seed GerminationTraits of Thymus kotschyanus in Laboratory Conditions

Abstract. The introduction of nanoparticles into seed germination and seedling growth of plants might have a significant impact and thus, it can be used for agricultural applications for better growth and yield. The purpose of this study was to compare the effects of silica and silver nanoparticles on seed germination and early growth traits as well as percent and rate of germination, root length, shoot length, seedling fresh and dry weight and seed vigor index of Thymus kotschyanus. Experiment was conducted using a completely randomized design with four replications in winter 2014. Seed sources were from Sabalan rangelands, Ardabil province, Iran. Treatments were control (distilled water) and silica and silver nanoparticles with the concentration of 20 and 60%. Thirty seeds were sown in each Petri dish. Seed germination began from the fourth day after sowing and they were counted every day until germination was stopped. Seed germination was controlled for 14 days. The statistical analyses were conducted using analysis of variance (ANOVA). Duncan test was performed to examine the differences between the treatments. Results showed that the germination of T. kotschyanus was strongly affected by nano-silver treatments in comparison with nano-silica and control treatments. Overall, higher values of seed germination traits were observed in nano-silver (20%). Moreover, increasing silica nanoparticle concentration had enhanced the seed germination. In contrast, the increase of silver nanoparticle concentration had decreased the germination traits.