蚕豆对土壤中锶的累积及其器官分配特征分析

Characteristics of strontium accumulation and redistribution in organs of Vicia faba grown on Sr-contaminated soils

为了调查蚕豆不同生育时期对土壤中锶(Sr)的累积效应及Sr在各器官中的分配特征,采用盆栽试验,以外源施加Sr Cl2·6H2O(稳定同位素88Sr)模拟土壤受放射性核素90Sr污染,分析Sr在蚕豆各生育时期(苗期、现蕾期、开花期、结荚期、成熟期)及各器官中的累积、分配特征。结果显示,随外源Sr污染浓度的增加,蚕豆体内Sr的累积量显著增加(P<0.05),各生育时期对Sr的累积量呈现成熟期>结荚期>开花期>现蕾期>苗期,生物富集系数(BCF)和转移系数(TF)呈"上升"趋势,Sr在蚕豆各器官中的累积百分比表现为叶>茎>根(苗期和现蕾期)、茎>叶>根>花(开花期)、根>豆荚>茎>叶(结荚期)和茎>叶>根>荚壳>种子(成熟期)。同时,蚕豆根系对Sr的吸收速率与外源Sr污染浓度显著相关。综上认为,Sr在蚕豆体内具有明显的累积效应,并可转移到蚕豆地上部分各器官中,导致这些器官或组织被Sr污染。

The aim of this study was to investigate the characteristics of strontium accumulation and its redistribution in organs of Viciafaba grown on contaminated soils. Viciafaba was grown on SSSr-contaminated soils（simulating 90Sr pollution） under pot culture conditions, and the accumulation, transport, and organ redistribution of Sr were then analyzed at various growth stages. The growth stages included the seedling stage at 46 days, the budding stage at 87 days, the blooming stage at 136 days, the podding stage at 151 days, and the maturation stage at 176 days. The results showed that Sr accumulation by V. faba was significantly greater on soils with a higher Sr content（p[Sr] 25- 100 mg· kg^-1） （P〈0.05）. The accumulation of Sr at various growth stages showed the following pattern：maturation stage 〉podding stage〉 blooming stage〉budding stage〉seedling growing stage. The bioaccumulation factor（BCF） and the translocation factor（TF） of Sr in V. faba gradually increased with an increase in growing time. Meanwhile, the distribution of Sr in different organs showed the following pattern ： leaf 〉stem〉root（seedling stage and budding stage）, stem〉leaf〉root〉flower（blooming stage）, root〉pod〉stem〉leaf（podding stage）, and stem〉 leaf〉root〉pod shell〉seed（maturation stage）. Furthermore, in this study Sr uptake rates had a connection with the concentration of sr con- taminant in the soil. This implies that Sr has an obvious biological accumulation effect in V. faba, is easily transferred to aboveground parts, and results in serious pollution of the plant＇s organs and tissues.