The area known as Farrapos wetlands is a Protected Natural Area of Uruguay and is a RAMSAR site. It is characterized for being one of the most extensive fluvial wetlands of the country, with an important heterogeneity of environments. The aim of this work was to survey native legumes and the nodulating rhizobial symbionts present in this protected area in order to contribute to the conservation of native biological resources. Nodules of legumes growing in their natural habitat were collected for the isolation of rhizobia. Interestingly, each legume species presented nodules with distinct morphologies reinforcing the idea that nodule phenotype can be included as additional information in legume taxonomy studies. Nodulation ability of selected isolates was assessed in gnotobiotic conditions. Isolates were identified by analysing 16S rRNA sequences and characterized by phylogenetic analysis. Papilionoideae legumes harbour rhizobia from the Bradyrhizobium, Rhizobium, Azorhizobium and Ensifer genera, while nodules from the Caesalpinoideae, including the mimosoid clade, harbour Alpha-rhizobia belonging to the Rhizobium, Bradyrhizobium and Mesorhizobium genera, as well as Beta-rhizobia from the Cupriavidus and Paraburkholderia genera. We found that the Farrapos protected area possess a great diversity of rhizobia, with high host specificity in their natural environment.

被称为Farrapos湿地的地区是乌拉圭的自然保护区，是RAMSAR所在地。它的特点是它是该国最广泛的河流湿地之一，具有重要的环境异质性。这项工作的目的是调查该保护区中存在的豆科植物和根瘤菌的结节共生菌，以有助于保护本地生物资源。收集在其自然栖息地中生长的豆类瘤节，以分离根瘤菌。有趣的是，每个豆类物种都呈现出具有不同形态的结节，从而强化了这样的观念，即在豆类分类学研究中可以将结节表型包括在内。在致病菌条件下评估选定菌株的结瘤能力。通过分析16S rRNA序列鉴定分离物，并通过系统发育分析进行表征。Papilionoideae豆科植物的根瘤菌从根瘤菌，根瘤菌，Azorhizobium和Ensifer属，而从Caesalpinoideae结节，包括mimosoid分支，港湾阿尔法-根瘤菌属于根瘤菌，慢生与慢生根瘤菌从属，以及β-根瘤菌贪铜和Paraburkholderia属。我们发现法拉波保护区的根瘤菌种类繁多，在其自然环境中具有很高的宿主特异性。