The Effect of Silver Nano-particles on Microbial Contamination and In Vitro Growth of Apical and Auxiliary Buds of Hazelnut Cultivars

Apical and auxiliary buds of six cultivars of hazelnut were prepared in different seasons, and disinfected with different treatments (including sodium hypochlorite, silver nanoparticles supplementary disinfectant and mercuric chloride) and then were cultured on solidified MS medium. The percentage of bacterial or fungal infected and developed explants were recorded. In addition, the effect of different levels of BAP and IBA on the establishment and growth of explants were evaluated. The results indicated that silver nanoparticles was effective in reducing in-vitro microbial contamination of hazelnut explants, and caused minimal injuries to the growing tissues. In spring, the lowest bacterial and fungal infections, with the highest percentage of shoot growth were obtained in 2.5% sodium hypochlorite for 10 min and submergence of explants into 100 mg/l silver nanoparticles solution for 30 or 45 min after 2.5% sodium hypochlorite for 5 min. MS medium supplemented with 1 mg/l BAP and 0.01 mg/l IBA produced the highest percentage of shoot growth (47.22), number of leaves (6.22) and shoot length (1.87 cm), which was significantly higher than the other levels of BAP. While in summer and autumn, the lowest percentage of bacterial and fungal infection and the highest percentage of shoot growth were obtained with submergence of explants into 100 or 150 mg/l silver nanoparticles solution for 120 min after 2.5% sodium for 20 min. The highest percentage of shoot growth was observed in MS medium containing 3 or 5 mg/l BAP and 0.01 mg/l IBA.