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

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.

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.

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).

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.