钙对非洲凤仙铅累积特性的影响

摘要

The effect of Ca on Pb tolerance and Pb concentrations in Impatiens walleriana under Pb stress were studied.It showed that Pb inhibited the growth of I.walleriana and the biomass of the seedling decreased with the increase of Pb treatment concentrations.And Pb concentrations in the root and leaf increased with the increase of Pb treatment concentrations.Pb concentrations in organs were 10-250 mg/kg under Pb ≥100 mg/L treatment concentrations.The inhibition of Pb was aggravated after Ca pretreatment in 50,100 and 300 mg/L Pb treatment.The effect of Ca on Pb concentrations in organs varied with Pb treatment concentrations.Ca significantly increased Pb concentrations in roots in 50 and 100 mg/L Pb treatment and inhibited Pb concentrations in roots in 300 and 600 mg/L Pb treatment.Ca significantly decreased Pb concentrations in the overground parts in 100 and 300 mg/L Pb treatment.In 100 mg/L Pb treatment,the availability of Pb in the root and leaf significantly dropped and the Pb transfer was reduced by Ca.So that Pb tolerance in L walleriana was high and L walleriana was a Pb accumulator and not a Pb hyperaccumulator;Ca alleviated the toxin of Pb in L walleriana under 50,100 and 300 mg/L Pb treatment that was related to the reduce of Pb content in above ground organs and lower availability of Pb in seedling of L walleriana.%通过水培实验,研究钙对非洲凤仙铅耐性和累积特性的影响.结果表明,无钙处理下,随着铅处理浓度增加,非洲凤仙生物量逐渐降低,根系和叶片铅含量逐渐升高,铅处理浓度高于100 mg几时,非洲凤仙各器官铅含量在10～250 mg/kg之间;与无钙处理相比,外源钙显著促进50、100和300 mg/L铅处理下非洲凤仙的生长;钙对非洲凤仙各器官铅含量影响随铅处理浓度不同而不同,与无钙处理相比,钙显著促进50和100 ng/L铅处理下根系铅累积,显著抑制300和600 mg/L铅处理下根系对铅的吸收累积,钙显著降低100和300 mg/L铅处理非洲凤仙地上部分铅含量;铅处理浓度为100 mg/L时,钙显著降低铅在根系和叶片中活性,也降低根向地上部分转运.由此可知,非洲凤仙对铅具有较高耐性,是Pb富集植物;外源钙能够缓解一定铅胁迫对非洲凤仙的毒害作用,推测缓解效应与钙降低地上部分铅累积含量和降低铅在植株体内活性有关.