| 摘要: |
| 对1991年分离自南海大鹏湾海域的塔玛亚历山大藻单克隆培养林在不同光照条件、辐射强度（9.5，5.9 W/m2）（辐射剂量为：95，190，380, 760, 1520 J/m2）和营养盐（N，P）浓度下，进行紫外辐射敏感性的研究。结果表明，紫外辐射可以导致细胞变形、增大和死亡。不论在什么条件下，低剂量的紫外辐射（95 J/m2）就能使该藻的存活率和生长率大幅下降。此后，随着辐射剂量的增加，虽然存活率和生长率继续下降，但下降幅度渐缓。充足的营养盐和辐射处理后的连续光照对藻群的恢复有益，但在缺氮和缺磷条件下培养的藻群，可能由于生理活性减弱而导致对紫外辐射敏感性的迟钝。辐射强度对该藻的紫外辐射敏感性的影响十分显著，而且与辐射剂量具有明显的双重效应。 |
| 关键词: 甲藻 紫外辐射 塔玛亚历山大藻 生理 生态 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，9389008号 |
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| THE ECOLOGICAL EFFECTS OF UV RADIATION ON A TOXIC DINOFLAGELLATE ALEX ANDRIUM TAMARENSE |
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Qi Yuzao, Huang Changiiang, Ying Zhehong, Qian Feng
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Institute of Hydrobiology, Jinan University, Guangzhou 510632
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| Abstract: |
| A toxic dino?agellate Alexandrium tamarense collected in 1991, from Dapeng Bay in the South China Sea was studied to assess its sensitiveness to different UV radiative doses (0, 95, 190, 380, 760 and 1520 J/m2) under four different pairs of culture conditions, i. e., continuing light for 24h to continuing dark for 24h, different UV radiative intensities of 5.9W/m2 and 9.5W/m2, lack of nitrogen to half nitrogen concentration (6.17mg/L) and lack of phosphorus to half phosphorus concentration (646 ug/L).
The results showed that UV radiation changed the cell morphology, increased the cell size and even killed them. The averaged length and width of the distorted cells were 1.54 and 1.33 times more than the normal cells. Under all four experiments, a low dose of UV (95 J/m2) decreased greatly the survival and growth rates of A. tamarense. Although the survival and growth rates continued to decline as UV dose increased, the decrease rate became smaller and smaller. Light radiation and full supply of nutrients seemed to be good for the recuperation of the population exposed to UV radiation. However, the population pre-cultured under lack of nutrients (N or P) became insensitive to UV radiation probably due to the declined physiological activity. Higher UV doses significantly reduced the survival and growth rates, and effects were doubled with the increase of UV dose. |
| Key words: Dinoflagellate, UV radiation, Alexandrium tamarense, Physiology, Ecology |
