Effect of different copper sulfate concentrations on growth, mineral nutrient uptake and copper accumulation in Silybum marianum and Artemisia absinthium

This study was conducted to investigate the potential of copper (Cu) absorption and accumulation and the effects of its contamination on the growth and mineral nutrient content of Artemisia absinthium and Silybum marianum under greenhouse conditions. This was done under factorial experiment based on a completely randomized design and Copper sulfate (CuSO4.5H2O) solution was added to the pots with three replicates at 0 (control), 100 and 200 mg/kg and then seeds of two plant species were sown. Plant harvesting was done after two months when growth was completed and then plant growth characteristics and mineral elements (Ca, Mg, K, P, Fe, Zn, Mn, and Cu) were measured for roots and shoots. The results showed that there was no effect of copper sulfate stress on roots and shoots of A. absinthium while shoot biomass and root volume, area and length of S. marianum were significantly reduced. The Cu accumulation in roots of both plant species and in shoots of S. marianum significantly increased by increasing the copper sulfate in soil. The highest level of Cu accumulation was found in shoots and roots of S. marianum with 53.50 and 168.72 mg/kg dry matter, respectively. A transfer factor less than one for both plants indicated their ability to copper accumulation in the roots. Potassium content in the shoot of S. marianum was significantly greater than that in A. absinthium at treatment of 200 mg/kg. There was no effect of copper sulfate stress on the micronutrients content of A. absinthium while it caused a significant decrease in Mn and Zn in shoot and root of S. marianum, respectively, and a significant increase in Fe in the shoot of S. marianum.