Lead and Cadmium Toxicity on Seedling Growth and Metabolism of Trigonellafoenum-graecum L.

The present experiment was carried out to investigate the toxic effect of lead and cadmium on seedling growth and metabolism of medicinally important plant Trigonella foenum-graecum L. Physio-morphological changes was studied at early seedling growth under different concentrations (5, 10, 15 mg/l) of lead and cadmium. These metal showed toxic effect on seedling length, root-shoot ratio, dry weight accumulation, seedling vigour index. On the other hand, content of photosynthetic pigments viz. chlorophyll a, chlorophyll b and carotenoid were decrease in a dose dependent manner in both heavy metal solution. The content of total free amino acids, soluble proteins and soluble and insoluble carbohydrate were initially increased as compared to control but at higher concentration in both the metal treatment showed decreased in content. Oxidative stress induced by heavy metals in plant causing membrane injury as observed by enhanced level of malondialdehyde (MDA) and in all experiments, higher concentration of cadmium showed the maximum toxicity as compared to lead.