碳酸钙和粉煤灰对铅胁迫下小麦毒害的缓解效应

Calcium carbonate and fly ash as remediation agents for reducing lead toxicity to wheat

采用室内盆栽和网室盆栽的方法,研究了碳酸钙和粉煤灰对铅污染土壤的小麦幼苗生物效应、成熟期籽粒含铅量和蛋白质含量及生物产量的影响,探讨了碳酸钙和粉煤灰缓解铅毒害小麦的生理机制。结果表明,在轻度铅污染(铅为350mg/kg)的小麦农田,1.0g/kg碳酸钙或50g/kg粉煤灰对小麦生长有明显的促进作用,能有效缓解铅对小麦的毒害;在重度铅污染(铅为600mg/kg)的小麦农田,1.0～2.0g/kg碳酸钙或50～100g/kg粉煤灰对小麦铅毒害缓解效果较好。

Indoor and outdoor pot wheat growth experiments in Pb contaminated soils （two levels） were conduc- ted to determine the effects of adding CaCO3 or coal fly ash on physiological characteristics of wheat seedling as well as Pb and protein contents and yield of wheat grains. The mechanism of reduced toxicity due to addition of CaCO3 or fly ash was proposed. Adding 1.0 g/kg of CaCO3 or 50 g/kg of fly ash to the soil of less Pb （350 mg/kg） effectively alleviated its toxicity with enhanced wheat growth. A higher dose of CaCO3 （1.0-2.0 g/kg） or coal fly ash （50-100 g/kg） achieved better remediation of the more polluted soil （600 mg/kg）. The benefits of remediation were notable in （relative to the controls） longer roots and seedling, heavier dry weight, more chlorophyll, higher root activity, and lower contents of peroxidase （POD） isoenzymes and malondialdehyde （MDA）. The addition of CaCO3 or coal fly ash also resulted in less Pb and more protein in the larger quantity of wheat grains.