A shared genus-level arbuscular mycorrhizal fungal community associated with three native Cerrado tree species

The Cerrado contains a great variety of plants and soil microorganisms, including arbuscular mycorrhizal fungi (AMF), which coexist with most plant species and aid in the absorption of water and nutrients. Buriti ( Mauritia flexuosa ), Cerrado cashew ( Anacardium othonianum ), and pequi ( Caryocar brasiliense ) have food, economic and cultural importance in the biome, and their production in nurseries and use in the recovery of degraded areas depend, in part, on their symbiosis with these fungi. In this study, the AMF community associated with these three trees in Cerrado soil in the Vale do São Patrício region, Goiás, Brazil, was characterized. Sixty-three rhizospheric soil samples were collected, and the spore density, root mycorrhizal colonization, and occurrence of nine AMF genera were recorded. In addition to comparisons of means, several methods were applied: parametric and nonparametric tests with assumption checks and effect sizes, incidence-based diversity indices, permutational multivariate analysis (PERMANOVA, ANOSIM, PERMDISP), indicator values, and ordinations. The mean spore density was 180.9, 153.3 and 148.0 spores per 50 mL of soil in the Cerrado cashew, pequi and buriti, respectively, with no statistically significant difference among species according to the nonparametric tests. Root colonization also did not differ among hosts. At the genus level, the AMF community was similar among the three trees, with no significant difference in composition and no association between the genus and host and with a predominance of Glomus and Acaulospora . After correction for multiple testing, one pair of genera cooccurred significantly, Sclerocystis and Ambispora . Because no soil chemical or physical variables were measured and the sampling was restricted to a single season, the data indicate low apparent host specificity at the genus level rather than a mechanistic cause. The similarity among hosts may reflect shared local edaphic conditions, a hypothesis that requires direct confirmation.