Physiological study of Lemna minor as bioremediator under various ld Cycles

Response of Lemna minor, to hormones, biomarkers and enzymes towards various Light and Dark cycles was studied in Hogland's nutrient solution. Gibberellic acid 1.0 mg/lit had a remarkable effect in retarding the chlorophyll destruction, where kinetin had no effect on the retention of chlorophyll in any condition used. GA₃ treated plants enhanced the cell division and delayed the senenscence over kinetin which affected the frond multiplication. The effect of darkness is abolished by brief light exposures on biomarkers like frond weights, protein, Chlorophyll content which is clearly showed in catalase and peroxidase activity at various Light-Dark cycles. LD cycles in model A (continuous L&D) showed the adverse effect on chlorophyll contents. Chl b showed a steady decline with decreasing dark periods where as Chl-a is linearly increased. In model B, under treatments of LDCs, the content of Chl-a, Chl-b and Chl-total showed a decline order in comparison with control (1/4 L / 223/4D), no matter increasing their fresh weights. Protein content increased in fronds is unaffected after various LD interruptions.