Germination Responses of Soybean Seeds to Fe, ZnO, Cu and Co Nanoparticle Treatments
Engineered nanometals have been used as stimulants or micronutrients to improve yield and quality of crops. In order to elucidate the effects of important metal nanoparticles (NPs) on the germination of soybean seeds, early responses of this procedure were evaluated. Soybean seeds were treated with Fe, ZnO, Cu and Co NPs at different concentrations. Germination percentage, germination rate, primary root and leaf growth at morphological and cytological levels were analyzed. Obtained results indicated that treatment of soybean seeds promoted germination rate, the growth of primary roots and leaves, depending concentrations of metal NPs used. The number of germinated seeds treated with 50 mg/L Fe, ZnO and Cu NPs achieved 62.19, 66.41 and 57.62%, respectively, significantly higher than control. ZnO NP seemed to be the strongest in root growth acceleration. The maximum primary root length of 9.26 mm was obtained at ZnO NP concentration of 50 mg/L. The growth of leaves from the treated seeds was significantly faster than the control after 39 hours (h) of germination, especially treated with ZnO and Co NPs. Fe and Cu NPs did not show the influence in growth of primary leaves during the first 60 h of germination. The positive effect of metal NPs also revealed through the root mitotic index, which was increased from 26 to 34% compared to the control. The obtained results will provide an evident for further investigation of the response of plant cells at molecular level to nanometal application.