CADMIUM EFFECTS ON PHOTOSYNTHETIC PIGMENTS OF GERMINATING SEEDLINGS OF PIGEONPEA (CAJANUS CAJAN L.)

Cadmium (Cd) is a widespread heavy metal pollutant in the environment with a long biological half-life. It is easily taken up by plants. Treatment of three pigeonpea (Cajanus cajan L.) cultivars LRG30, LRG41 and ICPL85063 with different concentrations of cadmium (cadmium chloride: CdCl2¬.H2O) representing 0.02, 0.04 and 0.06 mM was used in the present study. Photosynthetic parameters like chlorophyll a, chlorophyll b, total chlorophyll, pheophytin a, pheophytin b, total pheophytin and total carotenoids content were analysed on 6-8 day old seedlings only. Cadmium treatment at all levels tested decreased chlorophyll and total carotenoid content, increased pheophytin content were observed in the order of increasing concentrations of externally supplied Cd in the three pigeonpea cultivars. The pigment composition was affected in the pigeonpea cultivars, LRG41 and ICPL85063 than LRG30 in response to Cd treatment.