Potencial de bactérias endofíticas no controle biológico da podridão vermelha do sisal

Abstract

Endophytic bacteria live inside plants without causing visible symptoms. These microbes are recognized for their potential as plant growth promoters, induction of disease resistance, and biological control activity against plant pathogens. Thus, the objective of this work was to isolate endophytic bacteria with potential for biological control of the bole rot disease of sisal, caused by the fungus Aspergillus niger and to evaluate the population densities of endophytic bacteria in sisal. Simultaneously the identification of isolates was performed by PCR. There was a higher bacterial density in symptomatic seedlings when compared to asymptomatic ones. Higher densities of bacteria were associated to stems, followed by roots and leaves. Ten isolates with antagonistic potential were obtained. In vitro assays resulted in 96 % inhibition of A. niger and greenhouse experiments in 60 % of disease inhibition. The genus Bacillus (three isolates) and Pseudomonas (five isolates) were identified by using PCR among the potential biocontrol agents. This work evidenciates the potential of endophytic bacterial isolates in the control sisal bole rot disease.