Effects of Nano silver on bacterial contamination and morphological and biochemical indices of in vitro GN15 almond rootstock

Nanotechnology has been able to pave the way for new methods in plant sciences and agricultural research. This research was carried out to investigate effects of Nanosilver in 4 concentrations (0 (control), 100, 150 and 200 mg L-1) at 8 replications in a complete randomized block design, on viability, bacterial contamination and some morphological and biochemical indices of GN15 explants at Urmia University. Shoot tip of cultivated GN15 rootstock were placed in MS medium containing 3% sucrose and 0.8% agar and different concentrations of Nanosilver and 1 mg L-1 BAP. Samples were recultured and were grown in growth chamber. By increasing Nanosilver concentration, the plants survival increased and the percentage of bacterial and fungal contamination decreased. Nanosilver increased the root length, leaf number, chlorophyll a, b, total chlorophyll, carotenoids and soluble carbohydrates at concentrations from 0 to 100 mg L-1. At higher concentrations, these factors were decreased. Increasing the concentration of Nanosilver decreased the shoot number and lateral branches number of explants, but did not have a significant effect on root number. Despite the effect of increasing the concentration of Nano silver on reducing bacterial contamination, up to 200 mg L-1, even to less than 10%, the best level, improving the biotic properties of GN15 explants was 100 mg L-1.