الخلاصة

The current study was conducted to investigate the anatomical and physiological effects of cadmium in Hydrilla verticillata and plant response when exposed to cadmium metals from (January to March 2017). Hydrilla verticillata was used to expose to different concentrations (0.5, 1, 3, 6 mg / l) for cadmium cd + 2 for 15 days laboratory during days (1, 7 and 15). The physiological tests were measured including (Total chlorophyll content, chlorophyll a, b, protein content, catalase enzyme, Superoxide dismutase (SOD)) and anatomical changes showed by preparation tissues slides for Leaves of plant. The highest values of cadmium was recorded during the experimental period in Hydrilla verticillata Leaves and highest proportion of removal ratio of the metals was (99.4%) at (3) mg / l during the 15th day. The bioaccumulation factor (BCF) of the Cd+2in the plant Leaves recorded the highest value at 0.5 mg / l during the 15th day. The current study showed a decrease in protein content during the experiment period, and a gradual increase in the SOD values during the experimental period compared to the control. The values of the efficiency of catalase enzyme of Cd+2 were observed to be the highest during the 7th day and decreased in the 15th day at concentrations 6 mg / l. The anatomical changes of plant showed increased air spaces and small area and mesophyll cells occupied the Leaves center and epidermis cells increased in thickness at 0.5 mg/l of metal, while at 6 mg/l decreased in thickness of Leaves and air space decreased in number and increased in the area and the mesophyll cells has been degradation and epidermis cells increased in thickness. The study concluded that the high concentration of heavy metals was caused by the dissolution of plant cells and plant death.