Effect of silver nanoparticles on vegetative growth indices and physiological parameters of canola (Brassica napus L.) under in vitro condition

Ethylene in plant tissue culture produces and accumulates under in vitro condition. It causes negative effects on growth of plants. Silver ion is known as an inhibitor of ethylene action under in vitro condition. In this study the effect of silver nanoparticle (0, 0.5, 1, 1.5 and 2 mg/L) was evaluated on canola under in vitro growth medium. After 28 days, the effects of silver nanoparticle were studied on growth, and content of photosynthetic pigments and proline in roots and shoots. The percentage of seed germination was decreased 40% at 2 mg/L of nanosilver concentration in comparison with the control. The nanosilver had significant effect on root height while decreased shoot height at all concentrations in comparison with the control. The enhancement of shoot weight, root weight and carotenoid content was 47, 73 and 76 percent under 1.5 mg/L of nanosilver treatment. The total chlorophyll and flavonoid content did not show any significant changes. Treatment of the plants with nanosilver decreased significantly anthocyanin pigment and some elements content in 1 and 1.5 mg/L of nanosilver in shoots. The proline content of shoot was decreased in all nanosilver treatments whereas did not show significant different in roots. In this study, it seems that nanosilver at 1.5 mg/L concentration was the best treatment as an ethylene inhibitor because of its positive effect on oxidative stress decrease and shoots weight increase in canola plant.