Growth response and phytoremediation efficacy of Daisy (Bellisperennis) in lead-contaminated Soil

Soil contamination caused by heavy metals is one of the important factors that endangers human health and plant growth which causes long-term effects on soil fertility and land value. Moreover, soil contamination leads to decreasing cultivated area and human access to valuable lands which discourages food production for growing population of world. Soil and water shortage resulted in social and economic problems and crisis. In order toinvestigation the potential of plant growth and phytoremediation capacity in the presence of heavy metal lead, this experiment was conducted in a completely randomized design. The treatments were applied to soil with six levels of lead nitrate (375, 750, 1350, 1850, 2450 mg / kg soil) and control without any lead nitrate, with 5 replications. The results showed that by increasing the concentration of lead in the soil, relative growth rate (RGR) and leaf area index decreased compared to the control. The rate of net absorption (NAR) has also decreased with increasing contamination level compared to control. By calculating the tolerance index (TI) for all levels of contamination, the highest rate of this index was shown for Levels 1 and 2, indicating that this plant is suitable for levels of 375, 750 mg / kg of soil to eliminate contamination.