| 摘要: |
| 工业革命以来，人类活动加剧了全球气候变化。臭氧层变薄，使到达地面的短波紫外辐射日益增加。同时，全球变暖导致海水混合层变浅，迫使混合层的浮游植物暴露于更高的紫外辐射下。近岸海域赤潮频发，中肋骨条藻作为赤潮的典型藻种之一，研究不同紫外波段对其生理特性的影响具有重要意义。本实验通过在室外培养，模拟赤潮爆发状态，对中肋骨条藻进行七种不同紫外波段的处理(分别使用280、300、320、340、360、380、400 nm截止型滤光板)。实验结果表明：紫外辐射会显著抑制中肋骨条藻的光合固碳速率，随着紫外波段逐步被滤除，光合固碳速率越来越高；>280 nm和>300 nm波段下的比生长率显著低于>400 nm波段处理；280-300 nm波段紫外对叶绿素a有显著的漂白效应，同时也会显著减少类胡萝卜素的含量；这表明紫外辐射对中肋骨条藻的抑制效应主要是紫外辐射B导致的，而紫外辐射A的作用不显著。在估测浮游植物海洋初级生产力的过程中，紫外辐射的作用往往被忽视。因此，在全球变暖的背景下，该研究对准确估测浮游植物日生产力提供了一定参考价值。 |
| 关键词: 光合固碳速率 生长 色素 中肋骨条藻 紫外波段 |
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| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Effects of different ultraviolet wavelength bands on the photosynthetic physiological characteristics of Skeletonema costatum |
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Zhu Rongjun, Gao Jiayu, Wu Yaping, Xu Juntian
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Jiangsu Ocean University
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| Abstract: |
| Since the iIndustrial rRevolution, human activities have exacerbated global climate change. Stronger short-wave UV radiation reaches the ground through thinner ozone layer. At the same time, global warming has resulted in shallower mixed seawater layers, in which phytoplankton have to be exposed to higher ultraviolet radiation. Red tide happens frequently in coastal waters and Skeletonema costatum is one of the typical algae species in red tide. It is of great significance to study the effects of different ultraviolet wavelengths on its physiological characteristics. In this experiment, seven types of UV bands were treated on Skeletonema costatum by culturing outdoors to simulate the state of red tide (using 280, 300, 320, 340, 360, 380, 400 nm cut-off filters, respectively). The experimental results showed that UV radiation could significantly inhibit the photosynthetic carbon fixation rate of Skeletonema costatum. The photosynthetic carbon fixation rate increased as the UV bands were gradually filtered out; the specific growth rates at > 280 nm and > 300 nm treatments were significantly lower than that of treatment of > 400 nm; 280-300 nm had a significant bleaching effect on chlorophyll a, and it also significantly reduced the content of carotenoids; this study indicated that the inhibitory effect of UV on Skeletonema costatum is mainly caused by UV, while the effect of ultraviolet A is not significant. In the process of estimating the primary productivity of phytoplankton in the ocean, the role of ultraviolet radiation is often overlooked. Therefore, in the context of global warming, this study provides a certain reference value for accurately estimating the daily productivity of phytoplankton. |
| Key words: Photosynthetic carbon fixation rate growth pigments Skeletonema costatum UV band |