Toxicity of Cadmium on Mineral Nutrition of Seedlings of Pigeonpea (Cajanus Cajan (L.) Millspaugh) Cultivars

Heavy metals are naturally occurring in the earths crust but anthropogenic and industrial activities have led to drastic environmental pollutions in distinct areas. Cadmium (Cd) toxicity was investigated with different concentrations representing 0, 0.02, 0.04 and 0.06 mM was used in three pigeonpea cultivars (LRG30, LRG41 and ICPL85063) on the changes in activity of mineral composition of roots, shoots and cotyledons. Except for the Cd accumulation in the respective metal-treated seedlings sodium, magnesium, potassium, calcium, iron, copper, zinc, manganese and molybdenum contents of the roots and shoots decreased with increasing concentrations of externally supplied metal ions and registered lower values when compared to their controls. However, the cotyledons of the three pigeonpea cultivars registered higher values when compared to their controls and the retention of various elements in the cotyledons increased with increasing concentration of externally supplied heavy metal ions. The decrease in the contents of different mineral elements was more in cv. LRG41 and ICPL85063 than in LRG30 in response to Cd treatment.