苋菜、小麦和玉米对铯的吸收和积累差异

苋菜、小麦和玉米用石英砂和Hoagland营养液进行盆栽培养,3叶期时,向培养液中添加不同浓度铯(0、0.5、1、5、10、20 mmol/L CsCI),在处理后第7、14、21、28天取样,分析3种植物对铯的吸收富集差异.结果表明:苋菜、小麦和玉米中铯含量均与处理浓度和时间呈显著正相关,在20 mmol/L铯浓度下处理28 d后达到最大值；苋菜对铯的富集能力和富集系数远远高于小麦和玉米,在处理浓度小于1 mmol/L时,小麦和玉米对铯的吸收富集无显著差异,但随着处理浓度的增加和处理时间的延长,小麦对铯的富集能力显著高于玉米；苋菜、小麦和玉米的根、茎、叶对铯的吸收富集也存在显著差异,苋菜叶片是主要的富集器官,富集量表现为叶、茎、根依次减小,而小麦和玉米的根是主要富集器官,富集量表现为根、茎、叶依次减小；铯显著抑制苋菜、小麦和玉米的生长发育,随着处理浓度的增加,生物量显著降低,根冠比显著增加.本研究结果表明苋菜是一种铯富集能力强的具有较高潜在应用价值的铯污染修复植物,而小麦和玉米是铯低富集植物.

Difference in Uptake and Accumulation of Cesium between Amaranth,Wheat and Maize

The seedlings of amaranth(Amarantus mangestnus),wheat(Triticum aestivum) and maize(Zea mays) were cultivated with quartz sand and Hoagland nutrient solution,and were treated with different concentrations of cesium(0,0.5,1,5,10,20 mmol/L CsCl) after the three-leaf stage,and the difference in absorption and accumulation of cesium in plants were analyzed on 7,14,21 and 28 d after cesium treatment.The results showed that the cesium content in three plants was significantly positively correlated with the treatment concentration and culture time,and it reached the maximum under 20 mmol/L concentration for 28 d.The cesium uptake capability and enrichment coefficient of amaranth were much higher than those of wheat and maize.When the concentration was less than 1 mmol/L,there was no significant difference in absorption and accumulation of cesium between wheat and maize,but with the increase of the concentration and culture time,the cesium absorption capacity of wheat was significantly higher than that of maize.Moreover,there were significant differences in cesium uptake capability in roots,stems and leaves of three plants.As for amaranth,leaves were main organ for cesium accumulation,and the trend of cesium content showed leaves > stems> roots.As for wheat and maize,the roots were the main accumulation organ,and the trend of cesium content showed roots >stems > leaves.In addition,cesium significantly inhibited the growth and development of three plants.With the increment of cesium concentration,the biomass significantly reduced,and the root to shoot ratio obviously increased.These results indicated that amaranth had strong cesium accumulation capability,which was a kind of potential remediation plants for cesium contamination,while wheat and maize were proved to have low accumulation capability for cesium.