Silicon Nanoparticles on the Enhanced Micropropagation of Hemidesmus indicus (L.) R. Br. ex Schult

Silicon nanoparticles (SiNPs) in Murashige and Skoog (MS) medium improved micropropagation of Hemidesmus indicus (L.) R. Br. ex Schult. (Apocynaceae), a valuable and threatened medicinal plant. Nodal explant-derived shoots amplified (130 shoots/inoculum/culture vessel) on MS medium + 1.0 mg L−1 SiNPs and 1.0 mg L−1 6-benzylaminopurine (BAP) + 0.5 mg L−1 kinetin (Kn) + 0.1 mg L−1 indole-3-acetic acid (IAA). These shoots exhibited superior growth over control. The SiNPs-derived shoots developed functional stomata, cuticle, multi-layered mesophyll, hypodermis, increased density of cells in the cortex, and vascular elements in the leaf and stem. In contrast, shoots generated on the control were with non-functional stomata, underdeveloped mesophylls, and few dermal, ground, and vascular tissues. The shoots were amplified on SiNPs-amended medium rooted maximum (99%) than control (90.3%) on 1/4th MS + 3.0 mg L−1 IBA (Indole-3-butyric acid). The rooted plants were acclimatized with ease and successfully transferred to the field. It is suggested that the addition of 1.0 mg L−1 SiNPs in the cultivation medium induced micro-morpho-anatomical features improving the micropropagation of H. indicus.