Effects of cadmium on growth and metabolism of Phaseolus mungo.

An attempt has been made to assess the response of Phaseolus mungo L. under influence of cadmium chloride (Cd Cl2) with special reference to growth, morphology, yield and biochemical aspects. Surface sterilized seeds of Phaseolus mungo L. cv. T-9 were exposed to various concentrations of Cd Cl2 solution (10(-2) M, 10(-4) M, 10(-5) M, 10(-8) M and control) for 12 hr at room temperature and these seeds were transferred to petriplates and polythene bags in triplicate. 10(-2) M conconcentration was found to have deleterious effects on seed germination, germination relative index, length and dry weight of root and shoot, shoot root ratio and seedling vigour index, plant height, phytomass, number of leaves and branches, leaf area and chlorophyll contents while 10(-8) M revealed slightly promotory effects. Phytotoxicity percentage and chlorophyll stability index were maximum in (10(-2) M) concentration, while minimum in 10(-8) M conconcentration of Cd Cl2. Nitrate and nitrite reductase activity was markedly inhibited at higherconconcentration. Low dose of Cd (10(-8) M) did not affect soluble sugar contents of seeds but it induced a significant increase at higher conconcentration (10(-2) M). It however, did not affect protein contents of seeds accept at higher concentration.