UV-B辐射增强对褶皱臂尾轮虫种群增殖的影响

Effects of UV-B radiation on the population growth of the rotifer Brachionus plicatilis

运用群体累计培养的方法研究了UV-B辐射增强对褶皱臂尾轮虫(Brachionus plicatilis)种群增殖的影响。结果表明:UV-B辐射对褶皱臂尾轮虫的种群数量、雌体抱卵率和种群增殖率都有显著影响。在本实验辐射强度(20μW/cm2)和剂量范围内,低剂量的0.24和0.48 kJ/m2处理组在实验的一定时期内对褶皱臂尾轮虫的种群数量和雌体抱卵率有一定的刺激作用;而高剂量的0.72、0.96和1.20 kJ/m2处理组对轮虫的种群数量和雌体抱卵率则有显著的抑制作用,甚至可导致整个种群的灭绝。褶皱臂尾轮虫的种群增殖率随UV-B辐射的增强显示出了一致性减小的变化规律,因此可以作为指示大气UV-B辐射强弱的生物指标。

The effects of different doses of UV-B radiation （0.00, 0. 24, 0. 48,0. 72, 0. 96 and 1.20 kJ/m^2 ） on the population growth of the rotifer Brachionus plicatilis feeding with algae Chlorella sp. were studied using the method of population accumulative culture. The results showed that the population numbers, the percentage of egg-bearing females relative to the total number of females and population growth rate of the rotifer Brachionus plicatilis were notably affected by UV-B radiation. At the experimental intensity of 20 μW/cm2 and in the dose range studied, the population number and the percentage of egg-bearing females of the rotifer Brachionus plicatilis could be promoted significantly by the low dose UV-B radiation （0.24 and 0. 48 kJ/m^2） , but significantly inhibited by the high dose UV-B radiation （0.72, 0. 96 and 1.20 kJ/m^2） during experimental period. More seriously, the high dose UV-B radiation even can lead to the extinction of the population. In addition, the population growth rate of the rotifer Brachionus plicatilis was highest in the control and showed a tendency of decrease with the dose increase of the UV-B radiation. The population growth rate can be used as an ideal biomarker for the enhancement of UV-B radiation.