Aims

The nitrogen-fixing symbiosis fixation between legumes and Rhizobium helps the plant to survive and to compete effectively on nitrogen poor soils. The soil environment attached to the root system is characterized by intense microbial activity. This work aimed to study the diversity of indigenous rhizobia living in the rhizosphere of forage pea in eastern and central Algeria.

Methods

Bacteria were trapped in vitro from collected soils. They were isolated from nodules by direct isolation or by bacterial trapping, and tested for nodulation. Further characterization was carried out to identify the isolates.

Results

Ninety-four isolates were obtained. Thirty-four were rhizobial strains that could, with two exceptions, establish root-nodule symbioses with the host plant. Different profiles of susceptibility to rhizobiophages indicated that the majority of isolates were likely to be members of the Rhizobium leguminosarum group of species. The strains revealed diverse plasmid profiles, and diverse restriction patterns of cpn60 gene amplicons and on Southern blot analysis of nodABC genes. Sequences of 16S rRNA gene showed that all isolates exhibited 99.85% identity with R. leguminosarum sv. viciae USDA 2370^T, R. laguerreae FB206^T and R. anhuiense CCBAU 23252^T. Analysis of cpn60 sequences revealed two groups. One of them clustered with ≤99% identity with R. laguerreae FB403. The second was clustered with ≤99% identity with R. laguerreae FB206^T.

Conclusion

Our findings suggest that the isolates may belong to the species R. laguerreae.

中文翻译：

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从阿尔及利亚东部和中部Pisum sativum L.自然栖息地捕获的本土根瘤菌的系统发生多样性

目的

豆科植物和根瘤菌之间的固氮共生固定有助于植物存活并在贫氮土壤上有效竞争。根系附着的土壤环境具有强烈的微生物活性。这项工作旨在研究生活在阿尔及利亚东部和中部饲草豌豆根际中的土著根瘤菌的多样性。

方法

从收集的土壤中体外捕获细菌。通过直接分离或通过细菌捕获从结节中分离出它们，并测试结节情况。进行了进一步的鉴定以鉴定分离物。

结果

获得了94个分离株。有34种是根瘤菌菌株，除了两个例外，它们可以与寄主植物建立根瘤共生菌。对根瘤菌噬菌体的敏感性不同，表明大多数分离株可能是豆科根瘤菌物种的成员。该菌株显示了不同的质粒图谱和cpn60基因扩增子的不同限制模式，以及对nodABC基因的Southern印迹分析。16S rRNA基因序列表明，所有分离株均与豆科根瘤菌具有99.85％的同一性。蚜USDA 2370 ^Ť，R. laguerreae FB206 ^Ť和R. anhuiense CCBAU 23252^牛逼。对cpn60序列的分析揭示了两组。其中一人聚集与≤99％同一性R. laguerreae FB403。第二个与拉格酵母FB206 ^T的聚集度≤99％。

结论

我们的研究结果表明，分离株可能属于拉氏乳杆菌。