| 摘要: |
| 采用共培养的方法，研究了塔玛亚历山大藻和中肋骨条藻种群竞争关系对UV-B辐射增强的响应变化。结果表明，不同的接种密度对塔玛亚历山大藻和中肋骨条藻种群竞争有明显的影响。当塔玛亚历山大藻和中肋骨条藻的接种比例为A∶S=1∶4时，中肋骨条藻在竞争中占优势；当接种例为A∶S=1∶1时，虽然塔玛亚历山大藻在竞争中占优势，但也受到了中肋骨条藻的抑制；接种比例为A∶S=4∶1时，塔玛亚历山大藻的生长竞争优势更加明显。UV-B辐射增强(在预备实验的前提下，选择1.4J/m2)可改变塔玛亚历山大藻和中肋骨条藻种群竞争的关系，使塔玛亚历山大藻种群竞争能力降低，中肋骨条藻种群竞争能力大大提高，从而导致处理Ⅰ(A∶S=1∶4)中，中肋骨条藻在竞争优势更加明显，在处理Ⅱ(A∶S=1∶1)中，中肋骨条藻在竞争中占一定的优势。 |
| 关键词: UV-B辐射 种群竞争 抑制作用 中肋骨条藻 塔玛亚历山大藻 |
| DOI： |
| 分类号: |
| 基金项目:中国博士后科学基金资助项目,20060390312号;山东省教育科技计划项目,J06I03号 |
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| UV-B RADIATION PLAYS DIFFERENT ROLES IN THE COMPETITION BETWEEN ALEXANDRIUM TAMARENSE AND SKELETONEMA COSTATUM |
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ZHANG Pei-Yu1,2, TANG Xue-Xi1, DONG Shuang-Lin1, CAI Heng-Jiang1, XIAO Hui1, FENG Lei1
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1.Division of Life Science and Technology,Ocean University of China,Qingdao 266003;2.Department of Environmental Science and Engineering,Qingdao University,Qingdao,266071
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| Abstract: |
| Eutrophication and harmful red tides have raised considerable concerns in marine environment. Complexity of blooming and fading mechanism, in physical, chemical & ecological processes, and lacks of knowledge on cysts germination, feeding, reproduction, of red tide organisms, make it difficult to be quantitatively described objectively. Therefore, the population dynamics of major red tide algae and the conditions of the occurrence remain a puzzle.
Ozone layer depletion was one of the major global environmental damages. UV-B radiation is harmful to the DNA of organisms. Increased UV-B radiation has altered greatly some ecological systems on the earth’s surface exposing potential danger to many marine organisms.
In this paper, we selected two red tide algal species [Skeletonema costatum (S) and Alexandrium tamarense (A)] in our research into UV-B radiation impact on their population competition, aiming to clarify the influence of intensified UV-B radiation on marine ecological system and red tide formation. Three treatments were set up in our experiment.
1. The initial inoculation density of A was 0.2×104 cells/ml, S at 0.8×104 cells/ml, at the proportion of A:S = 1:4;
2. The initial inoculation density of S and A were both 0.4×104 cells/ml at A:S = 1:1;
3. The initial inoculation density of A was 0.8 × 104 cells/ml, that of S 0.2×104 cells/ml at A:S = 4:1.
Results of these mixed cultures showed that different proportion could directly change the population competition between A and S. at A:S = 1:4, S grew dominantly. At A:S = 1:1, A overcame S. at A:S = 4:1, A overwhelmed S. Meanwhile, the responses of A-S population competition to UV-B radiation intensification was studied in the co-cultures. The intensification could favor S in the competition. This was why the rivalrousness of S changed more remarkably at A:S = 1:4, and S prevailed over A at A:S = 1:1 under UV-B radiation dosage of 1.4 J/m2. The UV-B radiation treatment could break the original growth of two in competition balance. Result of this experiment shows that A was more sensitive to UV-B radiation treatment than S. |
| Key words: UV-B radiation, Population competition, Inhibitation, Alexandrium tamarense, Skeletonema costatum |
