【摘要】 研究了微囊藻群体从底泥中释放进入水体的过程及这一过程与水体温度、光照及营养盐的关系 ,并比较了底泥和水体中微囊藻群体的生长特性。同时 ,比较了温度对经低温 (4℃ )处理的和处于对数期的Microcystis.sp .94 0的叶绿素荧光强度的影响。结果表明 ,在 15℃ ,30 μEm-2 s-1光照条件下 ,底泥中的微囊藻群体复苏开始启动 ,并于15d后开始上升到水体中。研究表明 ,存在于底泥中的微囊藻群体从底泥中迁移至上层水体的最适条件为 2 0℃ ,30 μEm-2 s-1。分别培养底泥微囊藻群体和同时期水体中的微囊藻群体 ,研究它们的生长特性 ,发现底泥中的微囊藻群体生长的最适温度为 2 0℃ ,光照强度为 30 μEm-2 s-1,与同期水体中的微囊藻群体生长条件相似。经低温 (4℃ )处理的微囊藻群体和生长周期处于对数期的微囊藻群体叶绿素荧光的影响的实验中 ,作者发现在 2 0℃和 2 5℃时 ,两种经过不同处理的微囊藻群体都随着时间增加而增长。但是 ,在 10℃和 15℃时 ,低温处理的微囊藻群体的叶绿素荧光随着时间增加而增长 ,而处于对数期的微囊藻群体的叶绿素荧光随着时间增加而降低。这表明长期处于低温和黑暗环境中的微囊藻细胞的光系统Ⅱ未受到严重的损伤 ,当环境转变有利于生长时 ,微囊藻细胞的光系统Ⅱ恢复活性。本研究结更多还原

【Abstract】 Effect of different environmental factors, such as temperature, light and N/P, on the recruitment of Microcystis colony has been studied. The growth characteristics of Microcystis colony samples from the sediment and pelagic zone were also compared. Meanwhile, the influence of temperature on the chlorophyll a fluorescence of both dormant and vegetative cells of Microcytis sp. 940 was investigated too. The results suggested that the recruitment of Microcystis colony out of the sediment was affected significantly by temperature and light, but not N/P. Microcystis colony in the sediment initiated growth at 15℃ and 30μEm -2s -1, then buoyed to the surface after 15 days. Cultured at 10℃ and 30μEm -2s -1,Microcystis colony in sediment couldn’t recruit during experiment. At 20℃ and 30μEm -2s -1,Microcystis colony grew actively in sediment, then moved into water after 5 days. The recruitment wasn’t affected by different N/P. Microcystis colony initiating growth could obtain enough N/P in sediment. After Microcystis colony moved into water, its growth was restrained by N/P in water. The growth characteristic of Microcystis colony in sediment and pelagic zone was researched. Incubated at 10℃ and 15℃, The growth of Microcystis colony in sediment and pelagic zone was laggard. In contrast to low temperature, its growth at 20℃ and 25℃ was active. The growth of Microcystis colony depended on light. With increasing of light intensity, its growth rate enhanced gradually. In darkness, it couldn’t grow normally and was decomposed gradually by bacteria. However, the Mcrocystis colony that were illuminated at 15℃ and 30μEm -2s -1 grew actively . N/P had no effect on the initiating growth of Microcystis colony in sediment, because the colony could absorb N/P from sediment. But Microcystis colony that had already come into pelagic zone would be constrained by N/P. It was found that the optimal condition for recruitment occurred at 20℃ And 30μEm -2s -1, and the optimal condition for its growth was also 20℃ and 30μ Em -2s -1, which was similar to the growth Microcystis colony in the pelagic zone. Incubated at 10℃ and 15μEm -2s -1, the F 0 fluorescence of the vegetative cells of Microcystis reduced, but that of the dormant cells of Microcystis sp. 940 increased similarly at 20℃ and 25℃, respectively. Microcystis colony that could survive in low temperature might have a mechanism to protect photosystem from damage. Our result illustrated that there is a close relationship between recruitment of Microsystis out of the sediment and the outbreak of Microcystis blooms.更多还原