Abstract

One of the primary objectives in agriculture is providing high-quality crops to consumers. Multiple techniques and methods are utilized to achieve this objective, including nanotechnology that depends on the use of very small materials, which will help in decreasing the amounts usually used with similar effects. Nanomaterials are used as fertilizers and also as component of nano-pesticides for plants. Despite their benefits, however, studies have noted their potential for cytotoxicity and genotoxicity. In this study, five nanoparticles (NPs) were tested to assess their effects on plants. The chromosomal aberration assay was used. The results showed that some NPs decreased the mitotic index (MI) significantly, which indicates the NPs’ potential cytotoxicity. In addition, different NPs’ treatments caused different types of chromosomal abnormalities e.g., chromosomes stickiness and disturbance of the metaphase and anaphase, lagging chromosomes, bridges, disturbed poles, micronuclei, s-metaphase, s-telophase, c- metaphase and bi-nucleus cells. All treatments had significant effects at p≤005. Treatments with NPs concentrations for 24 h affected the DNA content, AlO₂ and Fe₃O₄ NPs’ increased the DNA content, while CeO₂, TiO₂ and Ag NPs’ decreased it. High concentrations of the tested NPs decreased the DNA content. The study results showed that CeO₂ was the most harmful NP compared to the control and other NPs. Some types of chromosome abnormalities such as lagging chromosomes, bridge, and micronuclei indicate potential genotoxicity for these NPs. Despite of the positive effects, they also had negative side effects such as decreasing the MI and increasing the occurrence of different types of chromosomal abnormalities.

Key words: Cytotoxicity, genotoxicity, nanoparticles, mitotic chromosomes abnormalities.