Physiological and Growth Responses of Castor (Ricinus Communis L) Under Cadmium Stressed Environment

Cadmium (Cd) is considered as phytotoxic in nature, its toxicity on the plant development decrease the antioxidative enzymes activities under stress environment. Castor (Ricinus Communis L.) is a metal tolerant plant and its ability to survive in highly polluted soils. Castor plant exhibited the high level of the Cd stress in the soil and buildup the antioxidants i.e., super oxide dismutase (SOD), peroxidase (POD) and malondialdehyde (MAD) on the top of the ground parts under Cd stress. Castor plant grown in the treated soil for 30 days in various levels of Cd 0, 10, 25 and 50 mg kg-1 soil treatments. Stress caused by heavy metal toxicity effects on reduced the plant growth, biomass, of castor plant respectively under 25- 50 mg kg-1 stress as against to control treatment. Our results indicated that castor significantly enhanced the Cd contents in root, stem and leaves. The POD and SOD enzyme activities were significantly increased 215.30 µmol/g-1 and 53.20 U/g respectively under 50 mg kg-1 stress as against control. While, MAD and chlorophyll content 3.11% and 0.48%, proline content 2.23 to 1.75 µg-1 were decreased under 25 and 50 mg kg-1 Cd stress as against control. According to Pearson’s correlation the our research work exposed strongly positive relationship with root, shoot, proline and malionaldihyde.  Although the destructive relationship was demonstrated by PoD and SOD enzyme activities. Hence, this study recommended that castor can grow in highly polluted soils for phytoremediation