Biosynthesis of silica and copper nanoparticles fromTrichoderma,StreptomycesandPseudomonasspp. evaluated against collar canker and red root-rot disease of tea plants

Tea is an important beverage with several health benefits to human beings, but increase in tea diseases is of much concern in recent days. Amongst several stem and root diseases of tea plants,Poria hypolateritiacausing red root-rot andPhomopsis theaecausingPhomopsiscanker diseases are very important in terms of heavy crop loss in young as well as mature tea plantations, respectively. In the present study, indigenous biocontrol agents such as bacteria, fungi and actinomycetes were isolated from southern Indian tea soils collected from different agroclimatic regions and subjected to biosynthesis of copper and silica nanoparticles. Copper and silica nanoparticles were produced using selected indigenous biocontrol agents such asPseudomonas fluorescens,Trichoderma atrovirideandStreptomyces griseusand then characterise for their nature, size, shape, elemental analysis, distribution and functional groups. The results showed that copper and silica nanoparticles were inhibited the growth ofP. hypolateritiaandP. theae. Nanocopper and nanosilica were subjected to prepare various nanoformulations using suitable inert and eco-friendly carrier materials. Toxicity of nanoformulations was done using zebrafish model. It was confirmed that there was no toxicity of nanocopper and nanosilica when exposed to 0.5, 3 and 30 mu g concentrations in terms of viability percentage of embryo, hatching rate, body mass index and heartbeat counts. The present investigation could be a novel approach for the management of root and stem diseases in tea plantations which in turn useful to enhance tea quality parameters.

Automated summary

Tea diseases have been a major concern recently, and this study focused on using indigenous biocontrol agents to synthesize copper and silica nanoparticles for managing root and stem diseases in tea plantations. Results showed that nanocopper and nanosilica inhibited the growth of diseases, and were non-toxic to zebrafish.