Bactérias associadas à cana-de-açúcar: isolamento e potencial promoção de crescimento vegetal.

Abstract

The exploration and understanding of the mechanisms of bacteria-plant interaction may be used in management systems that seek a sustainable production of several crops in agriculture, mainly sugar cane, which has great importance in today's economy. Therefore, the objective was to evaluate the diversity of bacteria (endophytic and rhizoplane) associated with different varieties of cane sugar grown in the Northeast and select bacteria with potential to promote plant growth (nitrogen fixing and phosphate solubilizing) for a possible reduction of fertilizer. Endophytic bacteria, leaf and root, and rhizoplane were isolated from three commercial varieties (RB 92579, RB 867515 and RB 863129) of cane sugar grown in the Northeast, in areas with and without the application of Termiticide and in two seasons (4 and 10 months) of plant development. The bacteria were isolated in 10% TSA media and selective media NFB and selected based on their ability to solubilize inorganic phosphate and nitrogen fixation. At the end of the process were isolated about 410 strains in rich media (TSA) and about 245 isolated media NFB(diazotrophic), that for both harvests. In the interaction bacteria-cane sugar, the total population of yellow and white bacteria was influenced by the varieties of cane and evaluated by plant tissues, and its management, and, moreover, it was concluded that the varieties of sugarcane sugarcane grown in the Northeast have a bacterial community associated with potential application to plant growth promotion, since they have the ability to fix nitrogen, solubilize inorganic phosphate and produce AIA. Plant cane sugar grown in Pernambuco has a distinct community of endophytic bacteria in relation to other producing states, some being identified as the genus Burkholderia, Pantoea, Klebsiella, Pseudomonas and Enterobacter.