Resumo

The sugarcane assumes significant importance due contributions on energy, environmental, food and socioeconomic aspects. Several factors that contribute to the successful cultivation of this crop, as for example, the favorable climatic characteristics and the interactions with microbial communities in the soil. However, little is known about the microbial community and the interactions that occur in this crop, especially with important beneficial microorganisms such as arbuscular mycorrhizal fungi (AMF). These microorganisms form a symbiotic association with more than 80% of terrestrial plants, assisting it in the uptake of water and nutrients outside the depletion zone of the roots system. In this study we assess the influence of changes in the soil microbial community, promoted by inoculating serial dilutions of natural soil in sterilized soil, on the mycorrhizal colonization of Acaulospora sp. in sugarcane. The treatments consisted of sterile soil with the total microbial community (TMC) and three levels of dilution of the microbial community (10^-3, 10^-6 and 10^-9) with the AMF. In addition, TMC and AMF species were analyzed separately with three replicates per treatment. The mycorrhizal colonization was assessed at 30 and 60 days of cultivation, and the results were superior in both assessments in plants grown in soils with the presence of TMC and the first dilution (10^-3). At 30 days there significant differences were observed in the colonization at TMC and the third dilution (10^-9), indicating that the impact caused on the soil microbial community affected the colonization of the fungus. At 60 days there was a lower colonization in pots only inoculated with the FMA. These results indicate that the AMF Acaulospora sp. presents an interaction with the microbial community, what can promote the colonization of the sugarcane roots, indicating the importance of the biodiversity maintenance on the preservation of extreme important interactions for the plant development.