DIVERSIDADE FUNCIONAL DA MICROBIOTA ENDOFÍTICA E RIZOSFÉRICA DE Hymenaea courbaril L. NO CERRADO E PANTANAL

Abstract

The soil microbiota can influence the maintenance of biodiversity, contribute to nutrient cycling, promote plant growth, establish antibiosis to pathogens, and even help repair the environment, by establishing associations with plants. These relationships are of considerable interest to researchers, given that they may have numerous ecological and biotechnological applications. This study is the first report on the diversity of the microbiota associated with Hymenaea courbaril. The study evaluated the effects of the nutritional attributes of the soil on the functional features of the radicular, endophytic, and rhizospheric microbiota of Hymenaea courbaril, sampled in the Cerrado savanna and Pantanal wetlands, and the functionality of this microbiota for the promotion of plant growth. Samples of the roots and rhizospheric soil were obtained from specimens collected in the Cerrado and Pantanal. The study was based on the nutritional analysis of the soil and tests for the solubilization of phosphates CaHPO4, AlPO4, and FePO4, the synthesis of AIA and the enzyma ACC desaminase, as well as antagonist action toward the phytopathogens Fusarium sp. Rhizoctonia sp., and Sclerotinia sclerotiorum. A total of 56 bacteria and 21 fungi were isolated, and the analyses indicated that soil characteristics, such as the pH, organic matter, Fe in the root, plant, and soil, and Mn in the soil had an effect on the functionality of the microbial community. The analyses also determined the capacity, in different degrees, of some of the isolates to solubilize phosphates, CaHPO4, FePO4, and AlPO4, synthesize the phytohormone auxin and the ACC desaminase enzyme, as well as antagonistic action against Fusarium sp., Sclerotinia sclerotiorum, and Rhizoctonia sp. Overall, the results of the study indicate the existence of endophytic and rhziopheric microorganisms associated with Hymenaea courbaril that have the potential to promote plant growth, and may be exploited for the production of bioinoculants.