Division of Marine Biology and Ecology, Institute of Oceanography, University of Gdańsk, Av. Piłsudskiego 46, 81-378, Gdynia, Poland.
Division of Marine Ecosystems Functioning, Institute of Oceanography, University of Gdańsk, Av. Piłsudskiego 46, 81-378, Gdynia, Poland.
Environ Sci Pollut Res Int. 2018 Dec;25(36):36403-36411. doi: 10.1007/s11356-018-3579-5. Epub 2018 Oct 28.
The role of macroalgal allelopathy in aquatic systems has received increasing attention as a potential means of controlling cyanobacterial blooms. However, the allelopathic activity of Chara sp. on coexisting and bloom-forming picocyanobacteria is still largely unknown. Therefore, the laboratory experiments were conducted to investigate the allelopathic activity of extracts of Chara aspera, C. baltica, and C. canescens on the growth, the fluorescence parameters: maximum and effective quantum yield of photosystem II (PSII) photochemistry (F/F and ΦPSII, respectively) and photosynthesis parameters such as the initial slope of photosynthesis-irradiance (P-E) curves (alpha) and photosynthetic capacity (P) of the picocyanobacterium Synechococcus sp. Batch cultures of picocyanobacterium were exposed to three concentrations of extracts originating from three charophyte cultures and the effect was followed at three sampling times. Dried specimens of C. aspera, C. baltica, and C. canescens were extracted in the water-based matrix and the initial Synechococcus sp. inoculum, derived from unialgal culture media, was used. We found both negative and positive allelopathic effects of all tested Chara extracts on Synechococcus sp. The strongest adverse impact of picocyanobacterium growth was caused by C. baltica. This study clearly demonstrated that the allelopathic effect depends on the Chara species identity. Our results also suggested that some allelopathic Chara sp. have the potential to mitigate harmful cyanobacterial blooms in systems dominated by Synechococcus sp.
大型藻类的化感作用在水生系统中作为控制蓝藻水华的一种潜在手段受到越来越多的关注。然而，Char 属植物对共存和形成水华的微囊藻的化感活性在很大程度上仍然未知。因此，进行了实验室实验以研究 Chara aspera、C. baltica 和 C. canescens 的提取物对微囊藻生长、荧光参数：光合作用系统 II（PSII）光化学的最大和有效量子产量（F/F 和 ΦPSII，分别）以及光合作用参数如光合作用-辐照度（P-E）曲线的初始斜率（alpha）和微囊藻 Synechococcus sp.的光合作用能力（P）的化感活性。微囊藻的分批培养物暴露于来自三种 charophyte 培养物的三种提取物的三个浓度下，并在三个采样时间进行了后续跟踪。C. aspera、C. baltica 和 C. canescens 的干燥标本在基于水的基质中进行提取，并且使用源自单藻培养物的初始 Synechococcus sp.接种物。我们发现所有测试的 Char 提取物对 Synechococcus sp.都有负面和正面的化感作用。微囊藻生长的最不利影响是由 C. baltica 引起的。这项研究清楚地表明，化感作用取决于 Char 物种的身份。我们的结果还表明，一些具有化感作用的 Char 属植物有可能减轻由 Synechococcus sp.主导的系统中的有害蓝藻水华。
