Estudo de bactérias potencialmente promotoras de crescimento em Citrus sp

Abstract

Plant growth promoting bacteria shows beneficial mechanisms that can promote better development of the host plant. The interaction between host and bacteria can be affected by several factors, such as plant genotype, plant specie, and the niche with microorganims lived. The citros culture have a great socieoeconomic importance for the country, which is one of the largest producers and exporters of citrus fruits. The aim of this study were to evaluate the bacterial communities associated with diferente hybrid citrus genotype, and observed the bacterial density, associated with niches diferents and evaluate the potencial ability to become culture inoculantes. through the study of production growth promoters production substances. Bacterial strains were isolated from the rhizosphere niches, roots, stems and leaves of 13 different genotypes rootstock hybrids of citrus and evaluated its production capacity of amylase, cellulase, pectinase (polygalacturonase and pectate lyase), inorganic phosphate solubilization, IAA producing dependent pathway of tryptophan, the potential biological nitrogen fixation and production of siderophores. Data were analyzed using statistical nonparametric test of Kruskal-Wallis and Wilcoxon using the R software. The results showed that bacteria associated with citrus plants have great potential, and the population density varies from the niche and host plant. Of the 183 isolates from 80% of the isolates were positive for the production of IAA, producing up 85μg.mL-1, 55.7% produced one or more types of enzymes, solubilized 48% phosphate, 37% were positive for nitrogen fixation and 60% for the production of siderophores. Confirming the potential to be potential inoculants culture.