The effect of magnesium dioxide nanoparticles on morphological and physiological traits on Achillea millefolium L.

Achillea millefolium L. from Asteraceae family has valuable medicinal properties. Nowadays, nanotechnology plays a very important role in various scientific fields. Magnesium nanoparticles, like other bio-synthesized nanoparticles, has several properties which can cause positive or negative changes in the morphological and physiological characteristics of the plant which lead to an increase or decrease in their medicinal properties. In this study, in order to evaluate the effect of Magnesium dioxide nanoparticles spraying and time of spraying on morph physiological characters of Achillea millefolium L, an experiment was designed as split factorial based on a complete randomized block design with four replications in two years in Malard, Safadasht. Irrigation as the main plot at two levels such on: Irrigation every 7 days (control) and irrigation every 14 days, and Four stages of spraying (tilling, stem elongation, before flowering and after flowering) and application of different concentrations of Magnesium dioxide nanoparticles (0, 1, 3, and 5%) were factorial in sub-plots. Leaf area every month measured by leaf area meter to calculate CGR and NAR growth indices. Sampling was performed to measure traits such as relative water content (RWC) for each treatment 72 hours after the third stage of foliar application. At flowering time, plant height, flower dry weight and pedicel dry weight were measured. In general, it is concluded that by increasing the concentration of magnesium dioxide, the adverse effects of drought stress are reduced however, the tendency for nanoparticles to condense at higher concentrations appears to suppress their true effects.