| 摘要: |
| 微囊藻(Microcystis)是最常见的淡水水华蓝藻,它们对磷营养盐的竞争力是其成为优势种的最主要影响因素.本文以太湖水华中的3种优势微囊藻(Microcystis flos-aquae,Microcystis wesenbergii和Microcystis aeruginosa)为材料,比较研究了它们对正磷酸盐(K2HPO4)、三聚磷酸盐(Na5P3O10)、小分子溶解态有机磷(葡萄糖-6-磷酸,G-6-P)和大分子溶解态有机磷(卵磷脂)的吸收和利用能力.结果发现,3种微囊藻对4种磷形态有明显的嗜好.当磷浓度为0.2 mg/L时,M. flosaquae只在正磷酸盐下生长最快,M. wesenbergii在三聚磷酸盐和大、小分子有机磷下生长最快,M. aeruginosa在所有磷形态下生长都最慢.而当磷浓度为2.0 mg/L时,M. flos-aquae在所有形态磷下生长都最快.在2种磷浓度下M. wesenbergii都表现出最高的溶解态无机磷比例和光合活性Fv/Fm.以上结果说明,3种藻在磷形态利用方面存在明显的互补性差异,即低磷浓度下M. wesenbergii适宜利用的磷形态更多,高磷浓度下M. flos-aquae适宜利用的磷形态更多,而不论磷浓度高低,M. aeruginosa对4种形态磷的适应性最差.由此可知,可利用磷形态的丰富性只是部分优势微囊藻的竞争策略. |
| 关键词: 微囊藻 磷形态 溶解态无机磷 光合活性 太湖 |
| DOI：10.18307/2014.0307 |
| 分类号: |
| 基金项目:国家重点基础研究发展计划"973"项目(2008CB418001-1)资助 |
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| Utilization of phosphorus in four forms of the three dominant Microcystis morphospecies in Lake Taihu |
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YUE Tao1,2, ZHANG Delu3, HU Chunxiang1
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1.Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China;3.Department of Biological Science and Technology, Wuhan University of Technology, Wuhan 430070, P. R. China
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| Abstract: |
| Microcystis is the most common bloom-forming cyanobacteria in freshwater. Its ability in phosphorus utilization is considered as a major factor for their dominance. This study chose three dominant Microcystis morphospecies(Microcystis flos-aquae, Microcystis wesenbergii and Microcystis aeruginosa) in the blooms of Lake Taihu, and compared their growth and phosphorus utilization of orthophosphate (K2HPO4), polyphosphate (Na5P3O10), glucose-6-phosphate (G-6-P) and lecithin. The results showed that the three morphospecies represented differences to phosphorus of four forms. Under the concentration of 0.2 mg/L, M. flos-aquae grew fastest in K2HPO4, while M. wesenbergii had the highest growth rates in Na5P3O10 and lecithin. M. aeruginosa showed the lowest growth rates. On contrary, M. flos-aquae had the highest growth rates under the concentration of 2.0 mg/L. Furthermore, M. wesenbergii showed the highest dissolved inorganic phosphorus rates and photosynthetic activity in terms of Fv/Fm in both phosphorus concentrations. These results implied that there were variations in phosphorus utilization among the three morphospecies. M. flos-aquae had advantages in phosphorus utilization of different forms under phosphorus-replete conditions, while M. wesenbergii showed advantages at low phosphorus concentration. M. aeruginosa represented the lowest adaptability to phosphorus of different forms. Therefore, the adaptability to available phosphorus of different forms was the competitive strategy for part of Microcystis morphospecies. |
| Key words: Microcystis phosphorus forms dissolved inorganic phosphorus photosynthetic activity Lake Taihu |
