Diversidade funcional de bactérias diazotroficas isoladas do trigo tratado com biofertilizante e diferentes concentrações de fertilizante nitrogenado

Abstract

Bacteria Promoting plant growth have the ability to stimulate plant growth and promote protection of the host plant, reducing the use of nitrogen fertilizers and the environmental impact caused by agricultural practices. It was analyzed whether different doses of nitrogen and the presence or absence of the inoculant containing Azospirillum brasilense could interfere in the diazotrophic population, NMP, present in the rhizosphere and in the root of the wheat in a crop rotation system. The 80 isolates obtained from the wheat root and the 193 obtained from the rhizosphere using the NFb, JNFb, JMV and LGI media were submitted to biochemical tests to verify the production capacity of siderophores, protease, AIA, Cyanide and cellulase and phosphate solubilization to evaluate the potential of plant growth promoter of these bacteria. The different treatments did not interfere in the NMP found in both rhizosphere and wheat roots. The presence of the inoculant was shown to be higher in the isolation of the endophytic JMV medium and the rhizosphere NFb and LGI. The different doses of N did not interfere in the population in the different media. Of the endophytic isolates we highlight 25 that presented 3 or more biochemical activities, of which 2 performed all biochemical activities. These were submitted to quantification of AIA in which isolated isolates were high as the producer of this indolite. As for rhizospheric, 43 were distinguished by performing 3 biochemical activities or more, and submitted to quantification of AIA 5 they presented high production. The isolates that stood out were submitted to mass spectrometry (MALDI-TOF). The dendrogram of the isolates showed that isolates of the same medium and treatment presented better grouping which will be identified in the future.