اثر تیمار نیکل و سرب بر محتوای کلروفیل و تجمع این فلزات در گیاه یونجه (Medicago sativa)

Heavy metals have a important roles to environmental pollution as a result of human activities. Higher concentration of heavy metals in environment lead to a toxicity symptoms and growth inhibition in most plants. The aims of this study was Ni and Pb accumulation in alfalfa plants when its exposure in this metals and the effects of this heavy metals on photosynthetic pigments. In this study seeds of Alfalfa (Medicago sativa) were raised in the pots and plants grown after 21 days in 2-3 leaves stage were treated with the concentration of 0, 2, 4, 6 and 8mM NiCl2 and PbCl2. Then take place remove plants in 2stages (2 and 15 days after treatment) and were measured and compared chlorophyll content and heavy metal uptake in roots and shoots of plants. The results showed that significant decrease in total chlorophyll content in plants treated compaired with the control plants. Also that significant increasing Ni and Pb concentration in plant treated compaired with the control plant. This increase in shoot parts more than roots in both treatment and different concentration . It seems that play somewhat Alfalfa plant as a accumulator for a Ni and Pb metals.