Effects of different concentrations of nano TiO2 on germination and early growth of five range plant species

Current study evaluates the effects of different concentrations (0، 10، 100، 500، 1500 mgl-1) of nano tio2 on germination، radicle and Plumule growth of five range plant species Nitraria schoberi L.، Eurotia ceratoides F.، Salsola rigida Pall.، Halothamnus glaucus Botsch.، Kochia prostrate (L.) A. J. Scott، using a completely randomized design with four replications. The results showed that the concentration of 500 mgl-1 of nano tio2، not only had no negative effect on plants، but increased the germination of Kochia prostrata from 28% to 51% and Eurotia ceratoides from 68% to 84%. Concentration of 1500 mgl-1 had negative effect on germination and radicle growth of three species of Nitraria schoberi (decrease in germination from 32% to 20% and radicle length from 13. 85 to 10. 68)، Eurotia ceratoides (decrease in germination from 28% to 20% and radicle length from 11. 63 to 8. 78) and Kochia prostrate (decrease in germination from 68% to 56% and radicle length from 11. 3 to 8. 8). Generally، in most plants، low concentrations of tio2 didn’t have significant effect on germination and seedling growth، but in high concentrations (1500 mgl-1) due to toxicity effect، germination and seedling growth was reduced. Therefore، in the case of using nanoparticles، attention to dosage، which is effective and not causes toxicity، is very important.