Silver nitrate mediated improvement in micropropagation and amelioration of micro-morpho-anatomical structures in Oxystelma esculentum (L.f.) Sm.

Abstract

The present study highlights the effect of silver nitrate (AgNO₃) in the promotion of in vitro regeneration and morpho-structural growth and developments in Oxystelma esculentum (L.f.) Sm. The incorporation of AgNO₃ into the Murashige and Skoog (MS) medium resulted in a favorable enhancement of shoot proliferation. Among the different concentrations of AgNO₃ screened, 0.5 mg L⁻¹ AgNO₃ along with 0.5 mg L⁻¹ meta-Topolin (mT) and 0.25 mg L⁻¹ indole-3-acetic acid (IAA) stimulated the highest count, and length of shoots (143 shoots and 14.0 cm length) after 3 mo of incubation and the 3rd subculture. The in vitro–induced deformities in the tissues of the control stem and foliages were improved when the shoots were grown in AgNO₃-enriched medium. Silver nitrate increased the photosynthetic pigments and improved the formation of functional stomata. The AgNO₃-supplemented medium-derived shoots exhibited accelerated adventitious root induction (100% rhizogenesis, 21.0 roots per shoot) when the cut ends of shoots were treated with 200.0 mg L⁻¹ indole-3-butyric acid (IBA) for 5 min under greenhouse conditions. The incorporation of AgNO₃ with optimal plant growth regulators in the medium promoted overall growth. It prevented in vitro–induced morphological and anatomical anomalies in the leaf and stem, which considerably improved the greenhouse and in vivo survival of micropropagated plantlets.