The Brazilian dry forest (Caatinga) is located in one of the world’s largest tropical semiarid regions, and it occurs on two large geological environments named the crystalline and sedimentary basins. In order to determine the structure and the main drivers of the composition of communities of arbuscular mycorrhizal fungi (AMF) in the Caatinga, we collected soil samples from the rhizosphere of Jatropha mollissima, J. mutabilis, and Mimosa tenuiflora, species that occur in crystalline and sedimentary areas. Ninety-six AMF taxa were identified from soils collected directly in the field and trap cultures. Acaulospora, Glomus, and Rhizoglomus represented almost 49% of the taxon richness. The composition of the AMF communities differed between the crystalline and sedimentary areas and between the rhizospheres of the three plant species. Coarse sand, total sand, natural clay, calcium, soil particles density, flocculation, pH, and base saturation were the principal edaphic variables related to the distribution of these organisms. We registered nine and 17 AMF species classified as indicators, for the geological environments and plant species, respectively. Glomerospores of Glomerales predominated in crystalline basins, whereas glomerospores of Gigasporales prevailed in sedimentary areas; among the plant species, lower number of glomerospores of Archaeosporales and Glomerales was recorded in the rhizosphere of J. mollissima. The results show that the AMF community composition is shaped by geological environments and plant hosts. In addition, soil characteristics, mainly physical attributes, significantly influence the structure of Glomeromycota communities occurring in areas of the Brazilian semiarid.

巴西干旱森林 (Caatinga) 位于世界上最大的热带半干旱地区之一，它发生在两个称为结晶盆地和沉积盆地的大型地质环境中。为了确定结构和在卡丁加群落丛枝菌根真菌（AMF）的社区的组合物的主要驱动力，我们收集了从根际土壤样品麻疯板栗，J.木芙蓉，和细花含羞草，发生在晶体物种和沉积区。从直接在田间收集的土壤和陷阱培养物中鉴定了 96 个 AMF 分类群。Acaulospora，球囊和Rhizoglomus占分类群丰富度的近 49%。AMF 群落的组成在结晶区和沉积区之间以及三种植物的根际之间有所不同。粗砂、总砂、天然粘土、钙、土壤颗粒密度、絮凝、pH 值和碱饱和度是与这些生物分布相关的主要土壤变量。我们分别登记了 9 个和 17 个 AMF 物种，它们被列为地质环境和植物物种的指标。在结晶盆地中，Glomerales的球孢子占优势，而Gigasporales的球孢子在沉积区占优势；在植物物种中，在J. mollissima的根际记录到的 Archaeosporales 和 Glomerales 的球孢子数量较少. 结果表明，AMF群落组成受地质环境和植物寄主的影响。此外，土壤特征，主要是物理属性，显着影响巴西半干旱地区的Glomeromycota 群落的结构。