Abstract

CAVALCANTE DE LIMA, Robson; KOZUSNY-ANDREANI, Dora Inés; ANDREANI JUNIOR, Roberto  and  FONSECA, Lucas da. PHENOTYPIC CHARACTERIZATION OF ENDOPHYTIC DIAZOTROPHIC BACTERIAS ISOLATED OF SUGARCANE. Rev. Fac. Nac. Agron. Medellín [online]. 2011, vol.64, n.1, pp.5803-5813. ISSN 0304-2847.

The use of inoculants containing diazotrophic microorganism in sugarcane can contribute to promoting the growth of these plants and tp promote significant gains in productivity. The objective of this study was to characterize diazotrophic bacteria isolated from stalks of sugarcane. We used the means of a semi-solid NFB and JNFb without added nitrogen. Five strains were isolated native diazotrophs which were evaluated microscopically by Gram stain, the intrinsic resistance to antibiotics, fungicide Furadan (i.a. carbofuran) and insecticide Regent (i.a. fipronil ) and ability to fix nitrogen in greenhouse and field conditions. All isolates were characteristic of Gram-negative, and for the intrinsic resistance to antibiotics showed widespread resistance. A native UCCBc5 strain showed resistance to the fungicide Furadan and the insecticide Regente. Bacteria isolated UCCBc1 and UCCBc5 present capacity and efficiency of fixing atmospheric nitrogen under conditions of greenhouse. It was found that the strain UCCBc5 resistant to the fungicide Furadan and the insecticide Regente has capacity of fixing atmospheric nitrogen in field conditions. In the evaluation of doses of inoculation was observed that there is a dose of inoculant / efficiency of nitrogen fixation. These results indicate that endophytic bacteria can be used, in some cases as a substitute for nitrogen in sugarcane.

Keywords : Diazotrophic bacterias; sugarcane; antibiotics; carbofuran; fipronil.

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