Nano silver:: a novel nanomaterial for removal of bacterial contaminants in valerian (Valeriana officinalis L.) tissue culture

Bacterial contamination is a serious problem in plant tissue culture procedures. An experiment was conducted to evaluate the potential of nano silver (NS) to remove bacterial contaminants of valerian nodal explants. This experiment was conducted as a completely randomized design in a factorial arrangement with four replications and each replicate with ten explants. Treatments involved NS at two stages (before and after surface sterilization along with control) with three rates (25, 50 and 100 mg l(-1)) at three times of soaking (30, 60 and 180 min). Explants were cultured on MS medium supplemented with 5 mg l(-1) Kin and 0.1 mg l(-1) NAA. Results showed that using 100 mg l(-1) of NS solution after surface sterilization resulted in the highest percentage (89%) of disinfected explants. Nano silver solution did not affect the characters measured. On the basis of the data obtained in this experiment, it was concluded that NS had a good potential for removing of the bacterial contaminants in plant tissue culture procedures. As this is the first report on application of NS in in vitro culture techniques, further investigations on other plant species are needed to clarify the effectiveness of NS for the removal of bacterial contaminants in tissue culture of other crops.