effects of silver, nickel, zinc and zinc – copper nanoparticles on germination, seedling establishment and enzyme activity of alfalfa (medicago sativa) seed

in order to examine the effects of silver, zinc, nickel, zinc- copper nanoparticles on germination, seedling establishment, and enzyme activity of alfalfa seeds, a factorial experimental was conducted in a randomized complete design with three replications in the seed laboratory, college of agriculture and natural resources, university of tehran in karaj. the objective of this study was to determine the potential impact of nanoparticles on alfalfa seed and its tolerance threshold to various nanoparticles. according to the results, maximum reductions were observed in the germination rate and shoot length under 40 mg per liter of zinc-copper and silver treatment. in the growth chamber conditions, only germination rate index was significant at 1% level and 80 mg per liter of zn-cu indicated as the lowest treatment. catalase enzyme in alfalfa plants that treated with nanoparticle levels was significant at 5%, but no significant difference between the control and treated seedling with nanoparticle was detected for superoxide dismutase and ascorbate peroxidase activity. among the all nanoparticles, the only nanoparticle that absorbed in seedling was ni under 40mg/l treatment. based on the results, by comparing laboratory and growth chamber experiments, reduction of nanoparticle injury was observed in the growth chamber experiments that can be related to the kind of media substrate.