提高供镁水平对西洋参幼苗镉胁迫缓解作用研究

Study on Cadmium Stress of Panax quinquefolium Seedling under Increased Magnesium Level Mitigation

本研究通过水培试验探究镉胁迫下提高供镁水平对西洋参幼苗的缓解作用。通过增加Mg2+的用量对30μmol·L^(-1)的Cd^(2+)胁迫下西洋参幼苗的生物量、根系活力、保护性酶、荧光参数及镉的动态积累特性进行测定及分析,结果表明,30μmol·L^(-1)的Cd^(2+)胁迫显著抑制了西洋参幼苗的生长发育,随着增施不同浓度的Mg^(2+)后,西洋参幼苗均得到不同程度地缓解,表型指标中CM2组缓解效应最优;生理指标中CM3组缓解效应最优,但各指标与CM2组差异均不显著;在各部位镉元素积累曲线中,随着镁浓度的增加,Cd含量呈降低趋势,CM3组对镉吸收、积累的抑制效果最显著。结合西洋参幼苗的生长、生理特性及镉元素积累等方面进行综合分析,西洋参幼苗在30μmol·L^(-1)的Cd^(2+)胁迫条件下,最适的Mg2+培养浓度范围为4~5 mmol·L^(-1);提高供镁水平短期内可显著抑制镉元素的吸收与积累。

The effect of increasing magnesium concentration on cadmium stress in Panax quinquefolium seedlings was studied by hydroponics experiment.The biomass,root activity,protective enzymes,fluorescence parameters and cadmium accumulation characteristics of Panax quinquefolium under Cd^(2+)stress of 30 mol·L^(-1)were measured and studied by increasing the dosage of Mg^(2+).The results showed that the Cd^(2+)stress of 30 μmol·L^(-1)significantly inhibited the growth and development of Panax quinquefolium seedlings.With the increase of Mg^(2+)at different concentrations,the Panax quinquefolium seedlings were alleviated to different degrees.In the phenotypic index,the CM2 group had the best remission effect.Among the physiological indexes,the CM3 group had the best mitigation effect,but there was no significant difference between each index and the CM2 group.Among the physiological indexes,the CM3 group had the best mitigation effect,but there was no significant difference between each index and the CM2 group.Among the cadmiumaccumulation and enrichment characteristics of each part,Cd content showed a decreasing trend with the increase of magnesiumconcentration,and the inhibition effect of CM3 group on cadmiumabsorption and accumulation was the most significant.Combined with the growth,physiological characteristics and cadmiumenrichment characteristics of Panax quinquefolium seedlings,the optimal concentration range of Mg^(2+)under Cd^(2+)stress of 30 μmol L^(-1) was 4~5 mmol·L^(-1).It was concluded that magnesium can significantly inhibit the absorption and accumulation of cadmium.