10.22376/ijpbs.2019.10.1.p1-12 Volume 1 Issue 3 2010 (July - September) The twenty-first century is an era of Nanotechnology which deals with nanomaterials both in products & processes. The increasing utilization of products containing these nanoparticles is resulting in the release of nanoparticles into atmospheric, aquatic, and terrestrial environments during their manufacturing, transport, utilization, and disposal processes. This raises environmental concerns since these metals can lixiviate from the material and contaminate water and soil, affecting both plants and animals. Not many studies are present to check the phytotoxicity of nanoparticles. Hence an lessThan i greaterThan in vitro lessThan /i greaterThan effort is made to check the toxicity levels of widely used nanomaterials. The phytotoxicity of silicon dioxide nanoparticles is evaluated as a function of concentration (600 to 1200ppm) toward lessThan i greaterThan Vigna radiata lessThan /i greaterThan grown in culture bottles in Murashige and Skoog medium (MS medium, 1962) for 2 weeks. The phytotoxic effects are observed in the form of reduced development and chlorosis in the plants. The higher concentration of nanoparticles is attributed to the accumulation of the nanoparticles in the root system of the plants and this is supported by both morphological analysis and phytochemical assays. This study demonstrates that the silicon dioxide nanoparticles enhances the growth of lessThan i greaterThan Vigna radiata lessThan /i greaterThan at low concentrations but turns toxic at higher concentrations (1000ppm) and is observed to hamper plant growth. Dr. Neeta Shivakumar*, Darshan S, Jyoti Raikar and Nandita Ramprasad M Vigna radiata, seeds, silica nanoparticles, morphology, phytotoxicity 113-120