UV-B辐射增强对三种赤潮微藻DNA的伤害效应

运用生态毒理学和生物化学方法研究了UV-B辐射增强对赤潮异弯藻、亚历山大藻和中肋骨条藻DNA的伤害作用.结果表明,3种赤潮微藻的生长状况对UV-B辐射增强的敏感性不同;对UV-B辐射增强的敏感性由高到低依次是赤潮异弯藻、亚历山大藻和中肋骨条藻.随着UV-B辐射剂量的增加,3种赤潮微藻的DNA损伤程度提高,而且赤潮异弯藻DNA的损伤程度明显高于亚历山大藻和中肋骨条藻,亚历山大藻DNA的伤害程度又远远高于中肋骨条藻.UV-B辐射处理解除后,损伤DNA可明显恢复.赤潮异湾藻和亚历山大藻恢复培养6d,损伤DNA可明显恢复(P＜0.05);而中肋骨条藻恢复培养3d,损伤DNA可明显恢复(P＜0.05),说明3种赤潮微藻的DNA损伤水平不适合作为指示UV-B辐射增强的生物学指标.

Effects of UV-B radiation enhancement on DNA damage of three red-tide microalgae species

The ecotoxicological and biochemical study with Heterosigma akashiwo,Alexandrium tamarense and Skeletonema costatum showed that the test three species of red tide microalgae had different sensitivities to UV B radiation enhancement,and the order from high to low was Heterosigma akashiwo,Alexandrium tamarense and Skeletonema costatum .The DNA damage of algal cells increased with UV B radiation enhancement,being more notable in Heterosigma akashiwo than in Alexandrium tamarense and Skeletonema costatum ,and in Alexandrium tamarense than in Skeletonema costatum .The DNA damage of Heterosigma akashiwo and Alexandrium tamarense could be significantly repaired ( P <0.05) after 6 days of UV B radiation removal,and that of Skeletonema costatum could be significantly repaired ( P <0.05) after 3 days,which illustrated that the DNA damage of three red tide microalgae species could not indicate the damaged degree of marine microalgae resulted from UV B radiation enhancement.