Resumo

PACHECO-HERNANDEZ, X.J. et al. Evaluation of phytotoxic effect of deleterious rhizobacteria on the root growth of Axonopus affinis (Chase) and Lens esculenta (Moench). Polibotánica [online]. 2015, n.40, pp.137-152. ISSN 1405-2768.

Weeds are a group of plants that commonly generate a huge loss of land crops; the management strategies and contention of these plant species includes the application of herbicides, although in recently years, it is now an interest to the establishment of safety biocontrol mechanisms, with the employment of microorganisms for the weeds' management, one microbial group that has been employed is the Deleterious rhizobacteria (DRB), a non-parasitic rhizospheric bacteria that causes a subtledeleterious effects on plants through the production of harmful metabolites. The aim of the present work was to characterize the cyanide production of rhizospheric pseudomonads isolated from weeds of alfalfa crop and evaluates their phytotoxic effect on the root growth of Axonopus affins (Chase) and Lens esculenta (Moench) seedlings. According to the obtained results related with the evidence that the pseudomonads isolates were cyanogenic rhizobacteria and with their phytotoxic effect measured on the plant species under study, these rhizobacteria are recommended as biocontrol agents of grass weeds, because the inhibitory effect on A. affinis plantlets. Particular focus possess the Pseudomonas sp. A52 strain, because it presents not only activity as DRB, it has also activity as plant growth promoter, that makes to analyze this rhizobacteria regarding to its potential and action spectra for monocotyledonous and dicotyledonous weeds, and as a recommendable biocontrol agent with multiple activity.

Palavras-chave : weeds; deleterious rhizobacteria; cyanhidric acid; root growth.