Phyto-toxic Effect of Heavy Metal (CdCl2) on Seed Germination, Seedling Growth and Antioxidant Defence Metabolism in Wheat (Triticum aestivum L.) Variety HUW-234

Abstract

The experiments were conducted to assess the phytotoxic effect of heavy metal (CdCl₂). The responses of treatment effect comprises the variables germination %, length (cm), fresh weight and dry weight (mg) of shoot and root, root/shoot ratio, seed vigour index (SVI), reducing sugar, non reducing sugar, total sugar (mg g^-1), chlorophyll content (mg g^-1), cadmium uptake (ppm g^-1), proline content (µg g^-1), relative water content (RWC%) and superoxide dismutase (SOD, unit×10² g^-1 f. weight min^-1).  CdCl₂ treated sets showed reduction in percent of seed germination, length (cm), fresh weight and dry weight (mg) of shoot and root, root/shoot ratio, seed vigour index (SVI) with increasing the concentrations of CdCl₂ in comparison to control set. A reduction in breakdown of reducing sugar to non reducing sugar and total sugar is correlated with decline of amylase activity along with increasing the concentrations of CdCl₂ in comparison to control one. The chlorophyll content was found in decreasing trend with increasing the concentrations of CdCl₂ in comparison to control. However, the uptake of cadmium was increased with increasing the concentrations up to 100 ppm CdCl₂. The proline content and superoxide Dismutase (SOD) was found to be high in higher concentrations of CdCl₂ treated set and while the enhancement was started since initial concentration CdCl₂ (i.e., 25 ppm). However, the least amount was recorded in control set. On the contrary, RWC% was found to be reduced with increasing the concentrations of CdCl₂ up to 100 ppm even though the maximum RWC% was measured in control set.