Abstract—The present study is aimed at investigating the effects of zinc oxide nanoparticles (nano-ZnO) and titanium dioxide nanoparticles (nano-TiO2) on rice (Oryza sativa L.) roots. Three parameters are examined in this study: seed germination percentage, root length, and number of roots. The results show that there is no reduction in the percent seed germination from both nanoparticles, however nano-ZnO is observed to have detrimental effects on rice roots at early seedling stage. Nano-ZnO is found to stunt roots length and reduce number of roots. Whereas nano-TiO2 has no effect on root length. This study shows that direct exposure to specific types of nanoparticles causes significant phytotoxicity, emphasizes the need for ecologically responsible disposal of wastes containing nanoparticles and also highlights the necessity for further study on the impacts of nanoparticles on agricultural and environmental systems.

Index Terms—Zinc oxide, Nanoparticles, Rice root, Toxicity.

P. Boonyanitipong and B. Kositsup are with Chulalongkorn University, Bangkok, Thailand 10330 (e-mail: sucuait@yahoo.com; Corresponding author, B. Kositsup, e-mail: boonthida.k@chula.ac.th).
P. Kumar is with School of Environment, Resources and Development, Asian Institute of Technology, Pathumthani, Thailand 12120 (e-mail: pkipm @ait.ac.th)
S. Baruah is with Elektronmikroskopi och Nanoteknologi, The Angstrom Laboratory, Uppsala, Sweden (e-mail: Sunandan.Baruah@angstrom.uu.se).
J. Dutta is with Center of Excellence in Nanotechnology (CoEN), Asian Institute of Technology, Pathumthani, Thailand 12120 (e-mail: nanoait @gmail.com).

Cite: Prapatsorn Boonyanitipong, Boonthida Kositsup, Prabhat Kumar, Sunandan Baruah, and Joydeep Dutta, "Toxicity of ZnO and TiO₂ Nanoparticles on Germinating Rice Seed Oryza sativa L," International Journal of Bioscience, Biochemistry and Bioinformatics vol. 1, no. 4, pp. 282-285, 2011.