International Journal of Plant & Soil Science

Aims: Today, the use of nanoparticles has been studied in various fields of science. One of the sectors that is perhaps less dealt with is the physiology of medicinal plants. The present study is aimed at investigating the phytotoxicity or beneficial effects of titanium dioxide (TiO₂) and titanium dioxide nanoparticle (NP-TiO₂) treatments on seed germination, root and shoot length, photosynthetic pigments and possible inhibitory effects particularly NP-TiO₂ on Mentha piperita.
This study was evaluated in 2012-2013 in the Islamic Azad University of Falavarjan, Isfahan, Iran, research Laboratory.
Methodology: Seeds were treated with TiO₂ and NP-TiO₂. Each treatment was conducted with four replicates, and the results were presented as mean ±SE (standard error of the mean). Germination percentage, root and shoot length and photosynthetic pigments were analysed using the SPSS 18.
Results: The different concentrations of NP-TiO₂ and TiO₂ had a negative significant effect on germination percentage and shoot length. However, root length was significantly influenced by 100mg L^-1 concentration of NP-TiO₂ rather than nonNP-TiO₂ concentrations. Pronounced effect on photosynthetic pigments (chlorophyll a and b and carotenoids) was found in 200mg L^-1 concentration of TiO₂ and 100mg L^-1 concentration of NP-TiO₂.
Conclusion: The results of this experiment showed that TiO₂ in higher concentration had pronounced effects on photosynthetic pigments while lower concentration of NP-TiO₂ had significantly increased root length.