We evaluated symbiotic (rhizobia) and non‐symbiotic efficiency and the diversity of native communities of plant growth‐promoting rhizobacteria (PGPR) in soil samples from an area in recovery after iron mining (RA) and from adjacent phytophysiognomies (Ironstone Outcrops, Neotropical Savanna, Atlantic Forest) in the Quadrilátero Ferrífero region, MG, Brazil, in two climate seasons. Greenhouse experiments were conducted with siratro (Macroptilium atropurpureum) as a trap plant. The SPAD index in siratro was more effective in detecting the difference between the symbiotic efficiencies of the communities of PGPR than shoot dry matter, with readings of the SPAD index greater in RA. Genetic diversity, of 327 strains evaluated by partial sequencing of the 16S rRNA gene, showed 29 genera in the dry season and 19 in the rainy season, among these genera some recognized as nodulating and endophytes, and others potentially endophytes. Genera belonging to the phyla Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were found. The nodule‐forming genera Bradyrhizobium and Rhizobium and the endophytic Paenibacillus were those of highest occurrence in both seasons and in all phytophysiognomies. The greater symbiotic efficiency and the high genetic diversity of the rhizobacterial community found in RA indicate that soil rehabilitation is effectively in process. As most of native legume species form symbiosis with Rhizobium and mainly Bradyrhizobium, these bacterial communities are an important source of potential inoculant strains, as well as, a relevant feature for the successful establishment of diverse legumes for revegetation purposes.

中文翻译：

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受铁矿开采影响的地区以及具有高度遗传多样性的邻近植物生理学促进植物生长的根瘤菌群落

我们评估了铁矿开采（RA）后恢复区域和邻近植物生理学（铁石露头，新热带热带稀树草原）土壤样品中的共生（根瘤菌）和非共生效率以及植物促生根瘤菌（PGPR）原生群落的多样性，位于巴西MG的QuadriláteroFerrífero地区的大西洋森林，处于两个气候季节。用siratro（Macroptilium atropurpureum）进行温室实验。）作为陷阱植物。siratro中的SPAD指数比干物质更有效地检测PGPR群落的共生效率之间的差异，而RA中SPAD指数的读数更大。通过对16S rRNA基因进行部分测序评估的327个菌株的遗传多样性显示，干旱季节有29属，雨季有19属，其中有些属结瘤菌和内生菌，其他有内生菌。发现了属于酸性细菌，放线菌，拟杆菌，硬毛菌和变形杆菌的属。根瘤菌和根瘤菌的根瘤形成属和内生的杆状芽孢杆菌在两个季节和所有植物生理学中发生率最高。RA中发现的较高的共生效率和较高的根瘤菌群落遗传多样性表明，土壤修复正在有效进行。由于大多数天然豆科植物与根瘤菌（主要是根瘤菌）共生，这些细菌群落是潜在接种菌菌株的重要来源，并且是成功建立各种豆科植物以进行植被恢复的重要特征。