Effect of Different Concentrations of Titanium Dioxide Nanoparticles on Germination and Early Growth of Five Desert Plant Species

Aims: Studying the effects of nanoparticles on living organisms seems to be necessary, especially in plants as the first trophic level. Thus the phytotoxicity of different concentrations of nanoTiO2 on five desert plant species was investigated in the present study. Materials Methods: The phytotoxicity of different concentrations (0, 10, 100, 500, 1500mgl1) of nanoTiO2 on five desert plant species of Halothamnus glaucus Botsch, Haloxylon aphyllum L., Nitraria schoberi L., Zygophyllum eurypterum Boiss. Buhse, Halocnemum strobilaceum were investigated using seed germination percentage, radicle, and plumule elongation measurement. Experiments were conducted based on a completely randomized design with four replications. Findings: Outcomes of the study demonstrated that the application of nanoTiO2 had no adverse effect on germination at low concentrations (up to 500mgl1), it also increased the germination of H. aphyllum (72 to 88%). The concentration of 1500mgl1 had a negative effect on germination and radicle growth of three species of N. schoberi (decrease in germination from 32 to 20% and radicle length from 13.85 to 10.68cm), H. aphyllum (decrease in germination from 72 to 44% and radicle length from 6.105 to 4.03cm). Conclusion: Generally, in most plants, low concentrations of nanoTio2 did not significantly affect germination and seedling growth, but in high concentrations (1500mgl1) due to toxicity effect, germination and seedling growth were reduced. Therefore, in using nanoparticles, attention to dosage, which is useful and not causes toxicity, is significant.