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 nano-TiO2 on five desert plant species was investigated in the present study. Materials & Methods: The phytotoxicity of different concentrations (0, 10, 100, 500, 1500mgl-1) of nano-TiO2 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 nano-TiO2 had no adverse effect on germination at low concentrations (up to 500mgl-1), it also increased the germination of H. aphyllum (72 to 88%). The concentration of 1500mgl-1 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 nano-Tio2 did not significantly affect germination and seedling growth, but in high concentrations (1500mgl-1) 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.