Sterilising of tissue culture media and growth stimulation of banana seedlings at rooting and ex vitro nursery stages using chitosan silver nanoparticles at low concentration

Abstract

Banana is a major fruit crop in Vietnam. Plant tissue culture technology is used to produce a large number of disease-free and genetically identical banana seedlings. Tissue culture media are generally thermally sterilised at high temperature and pressure. In this study, the synthesised highly stable silver chitosan nanoparticles (AgCS) with an average size of 54 nm were utilised for sterilising plant tissue culture media without thermal treatment. After four weeks, the percentage of uncontaminated culture media at concentrations of 0.25 and ≥0.5 ppm reached 96.7 and 100%, respectively. Investigation of the effects of AgCS (0.25-4 ppm) on tissue-cultured banana plantlets at the rooting stage showed that AgCS at 0.25 ppm increased root length and fresh weight by 70 and 30%, respectively. The ex vitro banana plantlets derived from in vitro cultures supplemented with AgCS 0.25 and 0.5 ppm grew better than the control. AgCS (0.25-0.5 ppm) increased the number of new roots (about 5 times), root length (1.1-3 times), pseudostem length (1.4-1.7 times), and fresh weight (2.4-4.5 times). In conclusion, AgCS can be used as a culture medium steriliser and plant growth stimulant for in vitro and ex vitro banana plantlets.