Effect of Lead on Marsilea minuta Linn. Under Hydroponic Conditions

Soil heavy metal contamination is becoming a matter of great global concern. The extent of Lead (Pb) concentration which causes toxicity in lower vascular plants, pteridophytes, remains unclear. So the present study was carried out to investigate the extent of Pb accumulation with its impact on physiological and biochemical basis of heavy metal tolerance in Marsilea minuta Linn. Lead salt in lower concentrations (0 µM, 0.1 µM, 0.3 µM, 0.5 µM and 1.0 µM) was allowed to absorb by the plants for 12 days in hydroponic culture and a significant deterioration of the plant biomass was recorded. However, roots absorbed more metals than the leaves. Changes in leaf area, biomass allocation, chlorophyll content in leaf, total carbohydrate and protein content were monitored. Higher concentrations upto 1.0 µM reduced biomass and chlorophyll contents. A noticeable decrease in total protein content was noticed on early days of treatment followed by a sharp increase in 0.3 µM, 0.5 µM and 1.0 µM treatments. Total carbohydrate content were decreased, as compared to control condition, in 1.0 µM and increased in 0.5 µM treatment.