Application of Silver and Molybdenum Nanoparticles in In Vitro Propagation of Vanda tessellata Orchids: Effects on Growth, Morphogenesis, and Contamination Control

The potential for nanotechnology to increase the efficiency of tissue culture and control contamination is significant. The study investigated the effects of silver nanoparticles (AgNPs) and molybdenum oxide nanoparticles (MoO3 NPs) individually and in combination on in vitro culture of Vanda tessellata, focusing on contamination control, bud break, shoot multiplication, and root induction. The completely randomized design was applied to investigate the effects of different concentrations of AgNPs (0, 5, 10, 20 mg/L) and MoO3 NPs (0, 1, 3, 5 mg/L) in MS medium. The results showed that the application of these nanoparticles can effectively reduce contamination and increase growth responses in vitro. The results also demonstrated that the interaction of 10 mg/L AgNPs and 3 mg/L MoO3 NPs was the most favourable treatment for Vanda tessellata in vitro culture, as it recorded the lowest contamination (7%), the highest survival (91.67%), maximum bud break (12.68 days), maximum shoot multiplication (6.90 shoots/explant), maximum shoot length (4.25 cm), maximum number of leaves (11.80 leaves/explant), maximum fresh biomass (1.18 g), and maximum root induction (92%), while a hormetic effect was observed at 20 mg/L, as it recorded lower growth responses due to mild phytotoxicity. This indicates that the synergistic effect of silver and molybdenum oxide nanoparticles can effectively increase contamination resistance, growth responses, and morphogenic efficiency in Vanda tessellata. Therefore, this study provides valuable information to develop an efficient protocol for nanoparticle-assisted micropropagation of Vanda orchids.