Profile of fluorescent pseudomonads for biocontrol use isolated from a brazilian agroecological production system

Resumo

Major part of fluorescent Pseudomonads isolated from a mixed plantation of lettuce and carrot grown in an organic experimental station (Integrated Agroecological Production System) were identified as P. putida. Phenotypic characterization of these isolates indicated their specificity to their host plant. A cluster formed by strains with high percentage of similarity was predominant on carrot while in lettuce the isolates were grouped in discrete clusters. Genotypic characterization carried by BOX-PCR distinguished these isolates more precisely, in terms of species or genera, while ITS-RFLP pro- files confirmed specificity of the isolates for plants, or even for their compartments. These results suggested that there was a level of specificity in the interaction of fluorescent Pseudomonads and the host plant. Specificity may be an important feature to identify efficient BCA (biological control agents)/PGPR (plant growth promoting rhizobacteria)