锌铬复合污染对水稻根系可溶性糖代谢的影响

植物具有逐步适应逆境的能力,在不同生育期对逆境的适应程度不同。可溶性糖是植物碳代谢的主要物质之一,与植物的抗性有密切关系。通过盆栽试验,研究了锌铬复合污染下,在水稻(Oryza sativa L.)不同生育期,水稻根系可溶性糖的代谢。结果表明,随着土壤中锌、铬质量分数的增加,在水稻不同生育期,其根干质量及地上部分干质量均呈降低的趋势,而根冠比呈现一定的升高趋势;水稻根系可溶性糖含量呈升高的趋势。偏相关分析表明,在水稻不同生育期,土壤中锌、铬质量分数与水稻根系可溶性糖含量均呈显著或极显著的偏相关关系。锌在水稻孕穗期及灌浆结实期对水稻根系可溶性糖含量的作用均大于铬,在分蘖期小于铬。这表明在重金属胁迫下,水稻通过增加其根系中可溶性糖含量来协调源流库的关系,从而提高自身对锌铬复合污染的生态适应能力。

Effects of compound pollution of Zn and Cr on soluble carbohydrate metabolism of rice roots

The plant has the ability of accommodating itself to the adversity,and the ability of adapting extent is different at different growth stages. Soluble carbohydrate is one of the major metabolites in plant carbon metabolism,and it is closely correlated with plant resistance. By soil pot experiment,the soluble carbohydrate metabolism of rice roots were studied under compound pollution of Zn and Cr at different growth stages of rice plant. Roots and shoot dry weight of rice reduced with increasing of concentrations of Zn and Cr,but the ratio of root to shoot (W/W) and soluble carbohydrate content of rice roots had an increasing trend at different growth stages of rice plant. Partial correlation analysis showed that it was significant or highly significant partial correlation between Zn,Cr and soluble carbohydrate content of rice roots at different growth stages of rice plant. Zn had more influence on soluble carbohydrate than Cr at booting and filling stages of rice plant,and less influence at tillering stage of rice plant. It indicated that rice increased soluble carbohydrate content in roots to harmonize source-translocation-sink,and then,improved the ecological adaptability to com-pound pollution of Zn and Cr.