Ecophysiological responses of rice (Oryza sativa L.) to hexavalent chromium

The effects of hexavalent chromium (cr) were studied in rice plants by applying its different concentrations ranging from 50-500 mg/kg of soil. cr significantly altered growth of rice plants and reduced dry weights of shoot (7-58%) and roots (7-73%) in different treatments. cr impact was remarkably high on photosynthetic rate (21-62%),transpiration rate (5-59%),and stomatal conductance (21-66%). chlorophyll a and b and carotenoid contents were also reduced in cr-treatment plants by 17-47%,12-43%,31-50%,respectively. highly pronounced reductions were recorded in nitrogen (23-82%),phosphorous (4-37%),and potassium (6-42%) content of treated plant leaves. cr accumulation was extremely higher in shoots (3575-19150%),roots (1023-5869%),and seeds (21-249%) of treated plants compared with control. present investigation has reported injurious effects of cr6+ on different aspect of rice plants. cr accumulation in threshold amounts in plant parts and seeds is a matter of serious concern to human health as it causes cardiovascular diseases,kidney failure and cancer.