7种海洋微藻对UV-B辐射的敏感性差异分析

在实验室条件下研究了UV B辐射对 7种海洋微藻生长的影响 .结果表明 :7种微藻的相对增长率随着UV B辐射剂量的增强呈明显的下降趋势 (P <0 0 5 ) .实验微藻对UV B辐射的敏感性符合绿藻 >硅藻 >金藻的分类学规律 ,其中金藻 870 1是最敏感的一种 .叶绿素a和类胡萝卜素的 48h半数有效抑制浓度EC50 远远大于相对增长率的EC50 .分光光度法测定微藻在UV波段的吸收峰集中在UV C波段 .在UV B波段 ,每 10 4 个细胞的最大吸收度的顺序为 :绿藻 >硅藻 >金藻 .微藻对UV B辐射的敏感性可能与其在该波段的吸收度之间存在一致性关系

The sensitivity variability of seven species of marine microalgae to the influence of UV-B radiation

Acute toxic experiments to 7 species of marine unicellular algae were performed under laboratory conditions.Three phenomena were observed:The relative growth rate( K ) in treated groups provoked significant decrease( P <0.05)compared with the controlled groups. Chlorophyta and Bacillariophyta were more resistant while Chrysophyta was vulnerable in response to UV\|B radiation and Isochrysis galbama Park 8701 was the most UV\|B\|sensitive species.The values of 48?h chl.a EC 50 and 48?h car.EC 50 were much higher than that of 48?h K (EC 50 ),predicting that K was the most sensitive indicator among the three indexes.Spectrophotometric method was used to investigate the absorption in UV protion.Results showed that the absorption peaks concentrated in UV\|C spectrum.The order of absorbency per 10\+4 cells from low to high in UV\|B portion was Chlorophyta>Bacillariophyta>Chrysophyta ,which was concordant with the sensitivity order.The results also indicated a rough relationship between sensitivity and UV absorbency.