In epiphytic associations, cyanobacteria form the periphyton with phytoplanktonic algae and with aquatic macrophytes. In this study, we found homocytous and heterocytous filamentous strains of epiphytic cyanobacteria associated with submerged leaves of the aquatic fern Salvinia auriculata. Filamentous morphotypes can produce adaptive structures such as heterocysts, akinetes, and hormogonia. Based on the premise that light limitation and nutrient limitation affect the adaptive strategies of cyanobacteria epiphytic we hypothesized that the heterocysts production would be greater under nutrient scarcity and full sunlight conditions, akinetes would be predominantly produced under growth-limiting conditions, such as nutrient scarcity and shade, and hormogonia would be abundantly produced under shade. In addition, for purposes of recording, identification and assembling a collection, we carry out the isolation of cultivable cyanobacteria. We conducted an experiment in a greenhouse applying a shade cloth and Hoagland’s solution to manipulate, respectively, the light intensity and the concentration of nutrients. Both factors, light and nutrients, affected the production of adaptive structures. Heterocysts were produced in greater numbers when no nutrient was added and under full light. Akinetes were produced mainly in the treatments under shade and no nutrient addition. In its turn, hormogonia were produced in the treatments with nutrients and mainly in the shade. Accordingly, akinete differentiation was negatively correlated with that of hormogonia. We conclude that the non-addition of nutrients stimulates heterocysts production, as well as akinete production. Therefore, due to the BFN BNF performed in heterocysts, we suggest that in oligotrophic aquatic environments, cyanobacteria epiphytic on the roots of aquatic macrophytes can supply fixed nitrogen to the aquatic ecosystem. Besides, with the shading produced by macrophytes, and available nutrients, the production of hormogonia is stimulated due to positive phototaxis. At the end of the experiment, nine morphologically distinct strains were isolated and taxonomically classified, up to the level of family and genus, and will allow us to assemble a collection for future research.

在附生联合中，蓝藻与浮游植物藻类和水生大型植物形成附生生物。在这项研究中，我们发现了与水生蕨类植物Salvinia auriculata 的沉水叶相关的附生蓝藻同细胞和异细胞丝状菌株. 丝状形态型可以产生适应性结构，如异囊、运动体和激素。基于光限制和营养限制影响蓝藻附生适应性策略的前提，我们假设在营养缺乏和充足阳光条件下杂囊的产生会更大，动植物将主要在生长限制条件下产生，例如营养缺乏和阴凉处，在阴凉处会大量产生激素。此外，为了记录、识别和组装集合，我们进行了可培养蓝藻的分离。我们在温室中进行了一项实验，分别使用遮光布和霍格兰氏溶液来控制光照强度和养分浓度。这两个因素，光和营养，影响适应性结构的产生。当不添加营养物且在充足光照下时，会产生更多数量的杂囊。Akinetes主要在遮荫处理和不添加养分的处理中产生。反过来，在有营养的处理中产生了激素，主要是在阴凉处。因此，akinete 分化与hormogonia 呈负相关。我们得出的结论是，不添加营养物质会刺激异囊的产生，以及阿基尼特的产生。因此，由于 BFN BNF 在杂囊中进行，我们建议在贫营养水生环境中，水生大型植物根部的附生蓝藻可以为水生生态系统提供固定氮。此外，借助大型植物的遮荫和可利用的养分，由于正趋光性，激素的产生受到刺激。在实验结束时，九个形态不同的菌株被分离出来并进行分类分类，达到科和属的水平，这将使我们能够为未来的研究组装一个集合。