Nano-anatase TiO2 modulates the germination behavior and seedling vigority of some commercially important medicinal and aromatic plants

Abstract

Nanoparticles have been applied worldwide, posing substantial effects on the environment and its living organisms. Plants as sessile organisms are always exposed to considerable fluctuations of nanoparticles concentrations. In this research, the influence of different concentrations (0, 10, 20, 40 and 80 mg.L-1 ) of nanosized TiO2 were studied on seed germination parameters including germination percentage (GP %), mean time germination (MTG), germination rate (GR), germination index (GI) and seedling vigor index (SVI) of five different medicinal plant species namely Salvia mirzayanii, Alyssum homolocarpum, Sinapis alba, Carum copticum, Nigella sativa. Results indicated that significant differences in examined traits were found among the plant species and also among the employed TiO2 concentrations. Among the plant species, the highest GR (87%) was observed in S. alba seeds at the 20 mg.L-1 TiO2 concentration, however, in S. mirzayanii plants it was obtained at 80 mg.L-1 TiO2. The lowest MTG (1.55 day) was observed in A. homolocarpum seeds at 10 mg.L-1 TiO2 concentration. Moreover, the highest SVI (102.6) was observed in the 20 mg.L-1 of the reference treatment for S. alba seeds. In N. sativa seeds, the highest GI value (9.29) was found at the anatase concentration of 20 mg.L-1 . In conclusion, application of TiO2 stimulated the seed germination of all species. However, this response was dependent on the concentration of applied TiO2 and plant species as well.