Effect of Hydroxyapatite and Zinc Oxide Nanoparticles on the Germination of Some Seeds

germination. The present study aims to investigate the effects of hydroxyapatite (HA-NPS) and zinc oxide (ZnO-NPs) Nanoparticles on seed germination of four plant species; ( Raphanus sativus ), ( Solanum lycopersicum ), wheat ( Triticum aestivum L . ) and cucumber ( Cucumis sativus L . ). Seeds were treated with DI-water (control) and nanoparticle suspensions (HA-NPS and ZnO-NPs) solutions, at six concentrations of 10, 20, 50, 100, 200 and 500 ppm. The treatment of HA-NPS showed an inhibition effect on all treated seed germination with significant dose dependence. The inhibition effect was related positively to HA-NPS concentration and was significant at the rate of 50 ppm in radishes and tomatoes, and at 100 ppm in cucumber and wheat seeds. In ZnO-NPs treatment, the inhibition effect was related positively to ZnO-NPs concentration and was significantly started from 20 ppm in radish, tomatoes, and cucumber. Meanwhile, wheat seeds weakly responded to ZnO-NPs inhibition showing a significant effect when applied at 200 ppm. The germination index data (combined seed germination and root elongation), indicated that the response of the tested seeds against Hydroxyapatite Nanoparticles was evident at the highest applied rate (500 ppm), and was as follows: recommend the use