青菜对14CO2的吸收和积累动态

为了探明¹⁴CO₂在环境中的行为,采用同位素示踪技术研究了青菜对¹⁴CO₂的吸收和积累动态.结果显示,通过叶片光合作用从空气中吸收的¹⁴CO₂会向青菜其他部位组织输送并形成积累趋势,各部位组织中^１４Ｃ比活度随时间呈线性增长,增长速率介于95.3～270.2 Bq/(g·d)范围内, 大小次序为:菜心＞叶＞叶柄＞茎盘＞根.青菜对¹⁴CO₂(^１４Ｃ)具有强烈的富集作用,各部位的富集系数随时间呈快速增加,积累效应十分明显,其中菜心中的富集系数最大(48 d时高达156.4),叶片次之(48 d时为135.6). 青菜各部位^１４Ｃ比活度均随¹⁴CO₂引入次数的增加而递增,回归分析表明:各部位组织中^１４Ｃ比活度C的变化与引入次数N间呈线性正相关.青菜对空气中¹⁴CO₂的高富集特性可用来作为监测大气¹⁴CO₂污染的指示作物.

Uptake 14CO2 from air and accumulation of 14C in Chinese cabbage

Uptake1 4CO2 from air and accumulation of 14C in the Chinese cabbage were studied by using the isotope-tracer techniques in order to get a better understanding of the environmental behavior of14CO2.The results show that the CO2,which was uptaken from the air by the leaf photosynthesis,would be sent to the other part of the Chinese cabbage and form a accumulating trend.The specific activity of 14C in every tissue increases linearly with time,and the increasing rate is in the range of 95.3~270.2 Bq/(g.d).The order of rate in tissues is as below: cabbage heart > leaf blade > leaf stalk > basal plate > root.The Chinese cabbage has an intensive concentration of14CO2,and the concentration factor values increase rapidly with time.The concentration factor values in the cabbage heart reach the highest level(156.4 in 48 days) and following with the leaf blade(135.6 in 48 days).The specific activity in each part of the Chinese cabbage also increases with the introduction times of the 14CO2.Regression analysis has proved that the specific activity(C) of every part is positively correlated to the introducing times(N).Owing to its high accumulation of 14CO2,Chinese cabbage can be used as the indicator plant in the supervisor of14CO2 air pollution.