The effects of heavy metals on seed germination and plant growth on alfalfa plant (Medicago sativa)

Abstract

The effects of Cd+2, Cr+6, Cu+2, Ni+2, and Zn+2 on Alfalfa Plant (Medicago sativa) were studied in this research. The doses of 0, 5, 10, 20, and 40 ppm were used. The seed germination and plant growth were significantly affected by Cd+2 and Ci(+6) at 10 ppm, as well as by Cu+2 and Ni+2 at 20 ppm and higher concentrations. Zn+2 did not affect seed germination. The plant roots were exposed to 5 ppm-dose of Cd+2 5 and 10 ppm-dose of Cr+6, Cu+2, Ni+2, and Zn+2. Meanwhile, the dose of 5 ppm of Cr+6, Cu+2, Ni+2, and Zn+2 increased the shoot size by 13.0%, 59.0%, 35.0%, and 6.6%, respectively. Zn+2 were only promoted the shoot growth at the doses of 20 and 40 ppm.