Effect of Heavy Metals on Physiology and Biochemical Profiling in Cyamopsis tetragonoloba L

Abstract

In the present investigation effect of abiotic stress in the form of heavy metals was studied for their effect on biochemical parameters including seedling growth and fresh weight of Cyamopsis tetragonoloba L. For this seeds treated with different concentrations (10, 50, 100, 200, 500 and 1000 ppm) of Cu, Cd, Pb, Ni and Zn along with control.  Maximum reduction in seed germination percentage was observed at 1000 ppm concentration. It decreased up to 40% in Cd, 60% in Pb 83% in Ni and Zn and 93% in Cu, whereas it was found to be 100% in the control. The shoot length at 500 ppm concentration was drastically reduced to led than one third of control in case of cadmium. At 500 ppm concentration of lead it was reduced to less than half of control. It was observed that heavy metal significantly reduced the fresh weight of seedling of Cyamopsis tetragonoloba. The percentage decreased in the fresh wright of seedling due to heavy metal application as compared to control. With increases in concentrations of heavy metals there was a gradual decrease in total chorophyll content in Cyamopsis tetragonoloba  except in respect of Zn and Cu up to 10 and 50 ppm concentration, respectively where it was superior to control. It was observed that Zn and Cu were less inhibitory to the amount of total carotenoid content in comparison to other heavy metals. In the control of carotenoid content was 0.37 mg/g fresh weight which decreased to 0.1 mg/g in Cd 0.20 mg/g in Pb, 0.23 mg/g in Ni 0.26 mg/g in Zn and Cu of fresh weight  at 1000 ppm concentration. All biochemical parameters reduced at 1000ppm increasing from 10 ppm.