Phaseolus vulgaris is a grain cultivated in vast areas of different countries. It is an excellent alternative to the other legumes in the Venezuelan diet and is of great agronomic interest due to its resistance to soil acidity, drought, and high temperatures. Phaseolus establishes symbiosis primarily with Rhizobium and Ensifer species in most countries, and this rhizobia-legume interaction has been studied in Asia, Africa, and the Americas. However, there is currently no evidence to show that rhizobia nodulate the endemic cultivars of P. vulgaris in Venezuela. Therefore, we herein investigated the phylogenetic diversity of plant growth-promoting and N2-fixing nodulating bacteria isolated from the root nodules of P. vulgaris cultivars in a different agroecosystem in Venezuela. In comparisons with other countries, higher diversity was found in isolates from P. vulgaris nodules, ranging from α- and β-proteobacteria. Some isolates belonging to several new phylogenetic lineages within Bradyrhizobium, Ensifer, and Mesorhizobium species were also specifically isolated at some topographical regions. Additionally, some isolates exhibited tolerance to high temperature, acidity, alkaline pH, salinity stress, and high Al levels; some of these characteristics may be related to the origin of the isolates. Some isolates showed high tolerance to Al toxicity as well as strong plant growth-promoting and antifungal activities, thereby providing a promising agricultural resource for inoculating crops.

中文翻译：

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从位于委内瑞拉对比农业生态系统的特有菜豆品种中分离出的共生细菌的遗传多样性和特征。


菜豆是各国广大地区栽培的粮食。它是委内瑞拉饮食中其他豆类的绝佳替代品，并且由于其对土壤酸性、干旱和高温的抵抗力而具有巨大的农艺价值。在大多数国家，菜豆主要与根瘤菌和 Ensifer 物种建立共生关系，这种根瘤菌与豆科植物的相互作用已在亚洲、非洲和美洲进行了研究。然而，目前没有证据表明根瘤菌在委内瑞拉特有的 P. vulgaris 品种上结瘤。因此，我们在本文中研究了从委内瑞拉不同农业生态系统中的 P. vulgaris 品种根瘤中分离的植物促生长和固氮结瘤细菌的系统发育多样性。与其他国家相比，普通假单胞菌根瘤分离株的多样性较高，包括α-变形菌和β-变形菌。一些属于慢生根瘤菌、Ensifer 和中生根瘤菌物种内几个新系统发育谱系的分离株也在一些地形区域被专门分离。此外，一些分离株表现出对高温、酸性、碱性pH、盐度胁迫和高铝水平的耐受性；其中一些特征可能与分离株的来源有关。一些分离株表现出对铝毒的高度耐受性以及较强的植物生长促进和抗真菌活性，从而为接种农作物提供了有前景的农业资源。