Physiological, morphological and ecological studies on the multiplication of red tide organisms

1)分类学研究：我们澄清了分类学上的混淆如下：a)许多物理学家以Olisthodisus luteus的名字描述的藻类与H.akashiwo相同。2)细胞分裂和叶绿体复制：赤潮异弯藻的细胞分裂和叶绿体复制在细胞周期中作为独立的同步事件发生，此时细胞处于明暗状态。在12h L/12hD培养条件下，细胞分裂的同步性指数为0.79-0.83，表明同步性较好。这些结果表明赤潮细胞是分析各种生物事件的良好材料。在电子显微镜下观察到伴随细胞分裂和叶绿体复制的精细结构的变化。3)昼夜垂直迁移行为：赤潮藻细胞明显地显示出昼夜…更多垂直迁移。向上迁移在灯亮前几个小时开始，向下迁移在灯关闭前几个小时开始。这种昼夜垂直迁移行为与细胞比重的昼夜变化和/或中性脂肪在远离鞭毛基的核一侧的积累密切相关。这一行为也与氮代谢有关，在氮饥饿下，向上迁移失去了。这些结果表明赤潮藻细胞是分析细胞行为的良好材料。4)碳和氮代谢：赤潮藻的光合作用&lt；CO_2&Gt_2固定速率不受较高光强的抑制，光合作用的氧抑制很小。该藻细胞的光合作用&lt；CO2&gt；主要通过还原的戊糖磷酸循环进行，光合作用的主要储存产物是-lt；β&gt；-1，3-葡聚糖。在富氮条件下培养的细胞，硝酸还原酶活性有明显的日变化，而在缺氮条件下培养的细胞，硝酸还原酶活性的日变化不明显。这种变化模式与日垂直迁徙行为的变化模式具有很好的相关性。较少

1)Taxonomical studies : We have clarified the taxonomic confusions as follows: a) the algae described under the name of Olisthodiscus luteus by many phocologists is identical to H. akashiwo. b) Fibrocapsa japonica must be treated with an autonomous genus separated from Chattonella.2)Cell division and chloroplast replication : The cell division and chloroplast replication in Heterosigma akashiwo occurred as separate synchronous events during the cell cycle, when the cells were subjected to light-dark regimes. The synchronization index of cell division in cells cultured under a 12h L/12h D was calculted to be 0.79 - 0.83, indicating the better synchronization. These results indicated that H. akashiwo cells are an excellent material for the analysis of various biological events. Changes in fine structures accompanying with the cell division and chloroplast replication were observed using electrom microscope.3) Diurnal vertical migration behavior : H. akashiwo cells clearly showed diurnal … More vertical migration. The upward migration commenced a few hours before the light turned on and the downward migration a few hours before it was turned off. The diurnal verical migration behavior was closely correlated with diurnal changes in the specific gravity of the cells and/or the accumulation of neutral fat on the side of the nucleus away from the flagellar bases. This behavior was also correlated with the nitrogen metabolism, the upward migration being lost under nitrogen starvation. These results indicated that H. akashiwo cells are an excellent material fot eht analysis of cell behaviors.4) Carbon and nitrogen metabolism : The rate of photosynthetic <CO_2> fixation in H. akashiwo was not inhibited by higher light intensities, The oxygen inhibition of photosynthesis was very small. Photosynthetic <CO_2> fixation in this algal cell was mainly carried out through the reductive pentose phosphate cycle and <beta> -1,3-glucan was the major storage product of photosynthesis. The diurnal variations in nitrate reductase activity were found, if the cells were cultured in N-rich medium, whereas such variations could not be detected in cells cultured in N-starved medium. The pattern of variation was well correlated with that of the diurnal vertical migration behavior. Less