Investigating the Synergistic Effects of Nano CeO2 and Pr2O3 Rare Earth Element Oxides as Fertilizers on the Growth of Salvia Miltiorrhiza Bunge

The study aims to synthesize nano CeO2 and Pr2O3 materials to use as fertilizer for cultivation of the Salvia miltiorrhiza Bunge, which is also known as Danshen, an important medicinal plant in many Asian countries. The extraction experiments were also conducted to determine tanshinone IIA contents in the Danshen root to acutely explore effects of the nano-materials on accumulation of valuable medicine in the plant. The obtained results indicated that nano CeO2 and Pr2O3 applications significantly induced both growth and tanshinone IIA contents of the Danshen. Firstly, the CeO2 application greatly induced side branch and root development of the Danshen rather than the height of the plant, while the Pr2O3 application greatly induced plant height and root growth of the Danshen rather than side branch development. In comparison, the CeO2 effectively induced root growth and tanshinone IIA content in the Danshen rather than the Pr2O3 did. Finally, simultaneous applications of nano Pr2O3 and CeO2 revealed synergic effects to greatly promote the growth of the Danshen. The tanshinone IIA content extracted from the roots of the mixture Pr2O3 and CeO2 exposed Danshen was approximately 0.4318 %, which was higher than those of single CeO2 and Pr2O3 exposed plants.