Study of Antimicrobial and Growth-Stimulating Activities of Copper(II) Oxide Nanoparticles on the Microshoots of the Hybrid White Poplar × Aspen and Downy Birch under In Vitro Culture Conditions

The effect of copper(II) oxide nanoparticles (CuO NPs) of various morphologies at concentrations of 10–200 mg L–1 on the microshoots of the hybrid white poplar × aspen and downy birch was studied. Low NP concentrations increased sterility and stimulated growth, whereas high concentrations inhibited development. Nanospheres and nanoflakes reduced contamination more effectively than nanorods. For the white poplar × aspen hybrid, the use of nanoflakes at a concentration of 10 mg L–1 was optimal for sterilization and stimulation of multiplication, while for birch, nanospheres at concentrations of 10–100 mg L–1 were optimal for reducing contamination. White poplar × aspen exhibited higher resistance to the effects of CuO NPs, whereas birch was more sensitive to NP exposure. Overall, CuO NPs appear to be promising agents for micropropagation; however, further studies are required to minimize phytotoxic effects.