THE EFFECTS OF DIFFERENT CONCENTRATIONS OF NANO-SILVER ON ELIMINATION OF BACTERIAL CONTAMINATIONS AND PHENOLIC EXUDATION OF ROSE (ROSA HYBRIDA L.) IN VITRO CULTURE

Rose is known as the first and the most important cut flower all over the world. One of the common methods of mass production of this plant is propagation through tissue culture. The main limiting factor of rose tissue culture is bacterial contaminations and phenolic exudation in the establishment phase that significantly makes most of explants spoiled. Nano-silver is able to control and stop the bacterial contamination. In this experiment nano-silver was added to medium with concentrations of 0, 50, 100 and 150 ppm and in the other experiments explants were immersed in solutions of nano-silver with concentrations (0, 100, 200 and 400 ppm) in complete random design. The experiments were carried out with four replications. The results showed that the concentration of 100 ppm which is directly added to the medium can reduce bacterial contamination and phenolic exudation rate. Concentration of 200 ppm for 20 min after surface sterilization was the best treatment of immersion to control bacterial contaminations. High concentrations of nano-silver make regeneration of explants more and more slower and in some cases lead to destroy explants. In general, nano-silver had no effects on fungal contamination.