Enhanced rooting in in vitro derived shootlets of Jasminanthes tuyetanhiae T.B. Tran & Rodda (Apocynaceae, Asclepiadoideae) through microponic system

A microponic system (MP system), a propagation system combines micropropagation and hydroponic that, has been studied on some flower and fruit plants; however, the MP system has not yet been tested on herbal plants, especially Jasminanthes tuyetanhiae (Apocynaceae, Asclepiadoideae). This study used the MP system with nylon film (A4 cover nylon) to evaluate rooting, abnormal developmental phenomena, antioxidant enzyme activities, secondary metabolites of plantlets, and subsequent growth. Results showed that 2-cm shoots cultured on a micropropagation system obtained a rooting rate of about 50–60%, and plantlets recorded abnormal phenomena reaching 85% consisting of 22.33% vitrification, 19.33% leaf abscission, 43.33% callus at the root and only 15% plantlets without abnormalities. In contrast, the MP system pre-treated with 0.5 mg/L indole butyric acid (IBA) and supplemented with 4 mg/L silver nanoparticles (AgNPs) obtained 100% rooting and improved plantlet quality. Furthermore, the plantlets developed using the MP system recorded a 2-fold reduction in vitrification and leaf abscission compared to those using the micropropagation system. A reduction in callus formation and increased antioxidant activities were also noted. The acclimatization of plantlets derived from the MP system pre-treated with 0.5 g/L IBA and 4.0 g/L AgNPs was higher than the conventional treatments.