On the Role of Colloidal System Stabilizers in the Stimulating Activity of Copper Oxide Nanoparticles on Poplar Plants in Culture In Vitro

The effects of copper oxide nanoparticle solutions stabilized by nonionic surfactants (Tween 20 and Triton X100) and polyhexamethylene biguanide (PHMB) on various stages of clonal micropropagation of white poplar × aspen plants (Populus alba × Populus tremula) in culture in vitro are discussed. The use of stabilized nanoparticles at a concentration of 5 mg/L in the Murashige–Skoog culture medium at the stage of introduction into the culture in vitro allows an increase in the yield of sterile viable explants by 16.7–26.7%. During the multiplication stage, the positive effect of nanopreparations is noted by the multiplication coefficient. The maximum value of this indicator (3.3) was obtained for 5 mg/L nanoparticles stabilized with PHMB (compared to 2.6 in the control). For stimulating root formation in poplar microshoots, media with the addition of copper oxide nanoparticles stabilized by Triton X100 and Tween 20 turned out to be optimal. An increase in the number of rooted shoots by 10% and the number of roots per shoot by up to 46% is experimentally confirmed.