Exploring Bacillus thuringiensis coated zinc oxide nanoparticles for improving chili seed germination

Abstract

Agriculture plays a pivotal role in global food security, and the use of agrochemicals like pesticides and fertilizers is essential for enhancing crop yield. However, the overuse of these chemicals leads to environmental pollution and health risks. In this context, nanotechnology offers a promising solution to mitigate these adverse effects while improving agricultural productivity. This study focuses on the synthesis and application of Bacillus thuringiensis coated zinc oxide nanoparticles (Bt-ZnO NPs) to enhance the germination and growth of chili pepper seeds (Capsicum annuum). The successful synthesis was confirmed by characterization of the nanoparticles, with an average size of 130 nm. The combination of Bt and ZnO nanoparticles could provide dual benefits such as boosting plant development while minimizing environmental impact and may show insecticidal effect. The optimal concentration of 500 ppm of Bt-ZnO nanoparticles resulted in a notable enhancement in germination indices compared to the control. The values for germination percent (88.3%), root length (2.3 cm), shoot length (4.9 cm), seedling length (7.2 cm), seedling vigor index I (636.4), fresh weight (140.7 mg), and dry weight (13.3 mg) were all higher than those observed in the control group. Higher concentrations showed inhibitory effects, likely due to zinc toxicity. This study suggests that Bt-ZnO NPs, at appropriate concentrations, can be an effective tool for improving seed germination and promoting early plant growth, offering a sustainable alternative to conventional agrochemicals.