Silver Nanoparticles in the In Vitro Aseptic Establishment of Poinsettia (Euphorbia Pulcherrima Willd. Ex Klotzsch) Var. Belén

Abstract Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) is the worldwide symbol of Christmas, and its demand constantly grows. The main challenge for the poinsettia in vitro propagation protocol is to maintain aseptic conditions in the culture, as the latex present in poinsettia stems significantly contributes to carbohydrates and other molecules that promote the development of endogenous phytopathogens in the culture medium after establishment. Therefore, the primary objective of this work is to assess the efficacy of AgNPs in achieving an aseptic in vitro culture using six concentrations of AgNPs (0, 100, 200, 300, 400, 500, and 600 mg L-1) added to the MS culture medium. Entirely aseptic nodal segments were obtained with the addition of 300 to 600 mg/L of AgNPs. The best shoot induction and growth promotion without compromising explant viability was obtained with the addition of 400 mg L-1 to the medium. It is essential to note that shoot induction and growth promotion were achieved without the addition of 6-benzylaminopurine (BA) or naphthalene acetic acid (NAA), which have previously been reported as the optimal conditions for poinsettia micropropagation. These results highlight the potential of AgNPs to accomplish both tasks for in vitro establishment of poinsettia cultures, eliminating bacterial and fungal contamination, and promoting conditions for shoot induction and growth.