Influence of chitosan-stabilized silver nanoparticles on the physiological and biochemical state of potato plants (Solanum tuberosum L.) in vitro culture

The article contains the results of study of the influence of added to culture medium silver-containing chitosan- based nanocomposites (Chitosan-Ag) at a dilution of 1:500 and 1:1000 (the mass ratio of the components is 50:1 for Chit- Ag 50:1 and 100:1 for Chit-Ag 100:1) on the development of potato microshoots and microclones with a formed root system. Potato microshoots cultivated for 4 weeks on nutrient medium modified with nanocomposites were characterized by slow development and the absence of rhizogenesis, which indicates the toxic effect of the studied nanocomposite concentrations. When replacing the standard nutrient medium with nanocomposites modified for a potato microclone with developed roots, the Chit-Ag 50:1 reduced the rate of growth and development of microclones compared to control and pure chitosan. The Chit- Ag 100:1 nanocomposite had no influence on the microclone growth compared to the control, but reduced the root biomass compared to chitosan. The preservation of photosynthetic pigments and proline concentrations with decreasing the hydrogen peroxide level indicates the absence of the toxic effect of silver-containing chitosan-based nanocomposites on the formed potato microclones. The chitosan concentration increase in the nanocomposite composition helps us to reduce the toxic effect due to the formation of a dense stabilizing shell that delays the silver ion generation.