铁对尖刺拟菱形藻生长及光合作用的影响  

Effects of iron on the growth and photosynthesis of red tide diatom Pseudonitzschia pungens Grunow

作　　者：左冬梅[1] 韩志国[1] 武宝玕[2] 

机构地区：[1]暨南大学水生生物研究所,广东广州510632 [2]暨南大学生物工程系,广东广州510632

出　　处：《暨南大学学报（自然科学与医学版）》2002年第5期81-87,共7页Journal of Jinan University(Natural Science & Medicine Edition)

摘　　要：　目的:研究铁对尖刺拟菱形藻生长及光合作用的影响,探讨其作用机制及生态意义.方法:以赤潮硅藻尖刺拟菱形藻为材料,采用细胞计数、测光合放氧和测DCMU增益叶绿素荧光的方法,研究了不同铁浓度对该藻生长和光合作用的影响.结果:尖刺拟菱形藻的最适生长铁浓度为10-7～10-6mol/L,缺铁(10-9～10-8mol/L)抑制其生长.在10-9～10-6mol/L,随着铁浓度的增加,光合放氧及叶绿素合成均受到促进,荧光增益比率FD/FN上升,荧光产额F/Chla下降.结论:缺铁使光合器官吸收的光能减少,光合电子传递链的活性降低,从而抑制光合作用,延缓生长.提出"临界铁浓度"概念,并有可能作为预报赤潮的指标.Aim:To investigate the effects of iron on the growth and photosynthesis of the red tide diatom Pseudonitzschia pungens Grunow. Methods: The effect of different iron concentrations on Pseudonitzschia pungens was studied by using cell counter technique, DCMU-enhanced chlorophyll (Chl) fluorescence technique, and also by measuring photosynthetic oxygen evolution. Results: The optimum range of iron concentration for growth was 10 -7 ～10 -6 mol/L. Within the range of iron concentration from 10 -9 to 10 -8 mol/L, the algal growth was inhibited. With the increase of iron concentration from 10 -9 mol/L to 10 -6 mol/L, photosynthetic oxygen evolution and Chl synthesis were promoted. DCMU-enhanced fluorescence ratio F D/ F N increased and F /Chla ratio decreased with iron concentration increasing. Conclusion: Iron deficiency led to decrease of absorbed light energy by reducing the cross-section of light-harvesting complex. Iron deficiency also led to low photosynthetic electron transport activity. All of these inhibited photosystems, reducing the absorption, transfer and utilization of light energy, and lowering the photosynthetic capacity. As a consequence, algal growth was inhibited. It is suggested that the critical concentration of iron in seawater can be used as an indicator for the prediction of red tide occurrence.

关 键 词：尖刺拟菱形藻 铁 光合作用 DCMU增益叶绿素荧光 赤潮 作用机制 海洋污染 生长 

分 类 号：Q949.27[生物学—植物学] X55[环境科学与工程—环境工程]