蚕豆-土壤系统对^(14)CO_2的吸收和积累

Uptake ^(14)CO_2 from air and accumulation of ^(14)C in broadbean-soil system

为了探明14CO2在环境中的行为,采用核素示踪技术研究了蚕豆-土壤系统对14CO2的吸收和积累动态.结果表明,通过蚕豆叶片光合作用从空气中吸收的14CO2会向蚕豆其他部位组织输送并形成积累趋势,被检测到的14C比活度数值比较大,表明空气中的14CO2易于通过叶片吸收而进入蚕豆各组织器官中;蚕豆各部位组织中14C比活度随时间呈线性增长,增长速率介于20.3~45.1Bq/(g d),大小次序为:叶>茎>根>豆壳>豆粒.蚕豆对14CO2(14C)具有较强的富集作用,各部位的富集系数随时间呈快速增加,其中叶片中的富集系数最高(56d时高达31.61),豆壳次之(56d时达25.57).利用蚕豆的这一富集特性可监测大气14CO2污染的情况.

Uptake 14CO2 from air and accumulation of 14C in broadbean-soil system were studied by using the isotope-tracer techniques,which was used to get a better understanding of the environmental behavior of 14CO2.The 14CO2,which was absorbed from the air by the leaf photosynthesis of broadbean,would be sent to the other parts of the broadbean and form a accumulating trend.14C specific activity was detected high,which demonstrated 14CO2 in the air easily got into every tissue of broadbean through photosynthesis.The specific activity of 14C in every tissue increased linearly with time.And the increasing rate was within the range from 20.3 to 45.1 Bq/（g·d）.The order of the rate in tissues was as below： leaf blade stalk root huskseed.The broadbean had an intensive concentration of 14CO2.The concentration factor values increased rapidly with time,and those in the leaf blade reach the highest level（31.61 in 56 days） and followed by the husk（25.54 in 56days）.Owing to its high accumulation of 14CO2,the broadbean could be used as the indicator plant in the supervisor of 14CO2 air pollution.