Toxicological effect of copper on growth and metabolism of barley (Hordeum vulgare L)

In vitro experiments were carried out to study the effect of various concentrations of Cu on germinatiion of seeds, seedling growth and metabolism of barley. The germination % (92,90,84,75 and 64), plumule and radicle length, number of lateral roots, fresh and dry weights, moisture %, total protein and sugar contents were found to be decreased with increase in copper concentration (0, 5, 25, 50 and 100 mgL⁻¹) respectively. The maximum protein and sugar contents (5 mgL⁻¹ Cu) 69.19 μg/mg and 7.55 μg/mg at 14^th and 66.63 μg/mg and 3.99 μg/mg fresh weight of tissue at 21^st days could be recorded following the exposure of Cu (5 mg/lit). Total chlorophyll and pheophytin pigment contents declined with increased copper concentration. The lower concentration of copper (5 mgL⁻¹) could induce most significant increase in total chlorophyll and pheophytin contents 1.560 and 1.491 at 14^th and 1.360 and 1.418 mg/g fresh weight at 21^st day of experiment. However carotenoid contents were found to be increased on 14^th and 21^st days of copper treatment. The activity of amylase was found to be reduced on 14^th and 21^st days in all the concentrations of copper used in the study. The maximum amylase activity 15.79 mg/g at 14^th and 13.73 mg/g fresh weight of tissue was also recorded following the exposure of minimum concentration of Cu i.e. 5 mg/L. The catalase and peroxidase activity was found to be increased with the increase in copper concentrations.