Effects of environmental factors on photosynthesis of a high biomass bloom forming species Prorocentrum donghaiense

利用测定净光合放氧速率的方法研究了温度、盐度、pH值和光照强度对东海原甲藻(Prorocentrum donghaiense)光合作用的影响.东海原甲藻适宜的温度范围是15～30℃,最适温度22～28℃,低于9℃和高于33℃,不能进行光合作用;适宜的盐度范围为22～35,最适盐度28～30;适宜的pH范围较小,为6.0～9.0, 最适pH值范围7.5～8.5,与所生活的海洋环境一致,pH高于9.5,不能进行有效的光合作用,pH10.0可致死全部细胞;光饱和点在600 μmol/(m~2·s)附近,在更高光强下没有发生光抑制.测定的对光合作用适宜的条件和最适条件与他人培养试验结果一致,与东海原甲藻赤潮发生现场的生态调查结果吻合.表明通过测定光合作用速率对主要生态因子变化的响应,可以掌握藻类生长繁殖对主要生态因子的要求以及对这些因子变化的适应能力.了解赤潮藻的生理生态特性是认识赤潮发生机理的基础,本研究结果为认识赤潮发生的机理提供了重要的信息.The effects of temperature, light intensity, pH and salinity on photosynthesis of Prorocentrum donghaiense were investigated by measuring a net photosynthetic oxygen evolution. The photosynthesis of the alga was sensitive to temperature. The temperature range for growth of P. donghaiense was 15～30℃ and the optimal temperature was 22～28℃. The photosynthesis depleted when temperature was below 9℃ or above 33℃. The suitable salinity ranged 22～35 and optimal salinity was 30. P. donghaiense was very sensitive to pH and suitable pH was 6.0～9.0, with optimal pH of 8.0 which was in accordance to that of the sea water. The photosynthesis of the alga was not efficient when pH was above 9.5, while pH10.0 was lethal to it. The saturation light intensity for P. donghaiense was about 600 μmol/(m~2·s). Photoinhibition was not observed under higher light intensities. The suitable and optimal conditions were in accord with the results of other culture experiments, and were consistent with the investigation data at the locale of P. donghaiense water bloom. The results indicated that the algal requirements for and adaptation to the main environmental factors can be realized by measuring the response of photosynthesis to the changes of main environmental factors. To understand the ecophysiological characteristics of algae is the base for finding out the mechanism of water bloom formation, and the results of this study provided important information for understanding the mechanism of water bloom formation.国家重点基础研究发展规划(973计划); 中国科学院武汉植物园创新工程所长基金中文核心期刊要目总览(PKU)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)01234-393