3种植物在水培方式下对锶的富集和迁移实验研究

Accumulation and migration of strontium in three plants under hydroponic culture

目的:研究绿萝、吊兰和吊竹梅对锶的富集和迁移情况,以及锶处理对植物吸收其他6种主要营养元素的影响。方法:采用水培扦插方式培养3种植物,每种植物设置1个对照组和3个水培液锶(浓度分别为1、2和3 mmol/L)处理组,每组培养绿萝和吊竹梅各4株,吊兰3株,整个实验在光照培养箱中进行,各组实验条件保持一致,实验周期为28 d。采用电感耦合等离子体发射光谱仪检测植物根、茎、叶组织中钙、铁、钾、镁、磷、硫和锶元素的含量。结果:在3 mmol/L锶处理下,3种植物根、茎、叶组织中的锶含量与对照相比显著升高(P<0.05)。从植物各组织中的锶质量分数来看,w锶,吊竹梅叶>w锶,绿萝叶>w锶,吊兰叶,w锶,吊竹梅茎>w锶,绿萝茎,w锶,吊竹梅根>w锶,吊兰根。随水培液中锶浓度的增加,植物组织中钙和铁含量呈显著降低趋势(P<0.05)。吊竹梅叶、茎和吊兰叶的迁移系数(TF)在0.36～2.54之间,在1 mmol/L锶处理下吊竹梅叶和茎的TF最高,分别达到2.54和2.33,随水培液中锶浓度的增加,其TF呈下降趋势。结论:对比3种实验植物,吊竹梅可作为锶污染水体修复的备选植物。水体中锶含量的增加可降低植物根系对钙和铁的吸收和富集。

OBJECTIVE:To study the accumulation and migration of strontium by Epipremnum aureum,Chlorophytum comosum(Thunb.)Baker.and Tradescantia zebrine Bosse.,and the effect of strontium exposure on absorption of other six main nutrients.METHODS:Three kinds of plants were maintained by hydroponic culture.Each kind was treated as control and 3 treatment groups with strontium concentrations of 1,2 and 3 mmol/L,respectively.Each treatment was experimentally cultured with 4 plants of Epipremnum aureum and Tradescantia zebrine,and 3 plants of Chlorophytum comosum.The entire experiment was carried out in the light incubator,and the experimental conditions of each treatment were consistent.The lasted 28 d.The contents of calcium,iron,potassium,magnesium,phosphorus,sulfur and strontium in plant tissues were determined by ICP-AES.RESULTS:The content of strontium in three kinds of plant tissues treated with 3 mmol/L strontium was significantly different from that of control(P<0.05).Strontium concentrations among the plant tissues were Tradescantia zebrine leaves>Epipremnum aureum leaves>Chlorophytum comosum leaves,Tradescantia zebrine stems>Epipremnum aureum stems,Tradescantia zebrine roots>Chlorophytum comosum roots.With the increase of strontium,the contents of calcium and iron in plant tissues were decreased significantly(P<0.05).In this experiment,the transportation factor(TF)of Tradescantia zebrine leaves,stems and Chlorophytum comosum leaves were between 0.36 and 2.54.The TF of Tradescantia zebrine leaves and stems were the highest under 1 mmol/L strontium treatment,reaching 2.54 and 2.33,respectively.With the increase of strontium concentration in hydroponic solution,the TF showed a downward trend.CONCLUSION:Compared with the 3 experimental plants,Tradescantia zebrine can be used as an alternative plant for strontium phytoremediation in contaminated water.The increase of strontium content can reduce the absorption and accumulation of calcium and iron in plants.