内陆水体盐度升高对小球藻生理特性的影响

全球气候变化引起内陆水体盐度缓慢升高，对浮游植物造成显著影响。为了探究水体盐度升高对浮游植物生理特性的影响，以普通小球藻为试验对象，在原水和不同盐度（1、3、5 g·L^-1）条件下研究普通小球藻生长增殖情况，分析其抗氧化酶活性及对光合作用的生理响应。结果显示，盐度升高会抑制普通小球藻生长，当达到3 g·L^-1以上时抑制作用明显，细胞分裂增殖指标均明显下降，叶绿素a合成速率衰减，藻细胞膜损坏严重，同时其光合活性显著降低。这表明过高盐度（>3 g·L^-1）极有可能破坏藻细胞的生理结构和抗氧化能力，导致其生长增殖受到抑制。研究结果从细胞增殖和生理特性角度分析了水体盐度变化对水体浮游藻类的影响，以期为保护内陆水体生物多样性提供参考。

Effect of Salinity Rising of Inland Water on Physiological Characteristics of Chlorella vulgaris

With the change of global climate， the problem of salinity slowly rising of inland water has a remarkable effect on the phytoplankton. To investigate the effect on physiological property of freshwater phytoplankton under the increasing salty environment， Chlorella vulgaris was taken as the research object and cultured at raw water and salinity（1， 3， 5 g·L^-1）. The effect of low salt level on growth and multiplication of Chlorella vulgaris was studied and its physiological response such as antioxidant enzymatic activity and photosynthesis were analyzed. The results showed that， with the rising of salinity， the growth of Chlorella vulgaris slowed down， the generating rate of chlorophyll-a decreased， its membrane structure was badly damaged， and the photosynthetic activity markedly decreased. All the results showed that high salinity （>3 g·L^-1） very likely damaged cells physiological structure and enzyme system of algae cells so that inhibited its growth and multiplication. The effects of salinity changes on planktonic algae were studied from the perspective of cell proliferation and physiological characteristics， which was expected to provide reference for protecting the biodiversity of inland water.