Caracterização de rizobactérias e avaliação de seu potencial antagônico a microrganismos fitopatogênicos e na promoção de crescimento em mudas de hortaliças

Abstract

The plant growth-promoting rhizobacteria may be an interesting way to promote increased vegetable production. Here, we aimed to isolate, identify, and characterize PGPRBs by using biochemical tests, sequencing of 16S ribossomal DNA, in vitro assessment of antagonism against pathogenic fungi, screening for indolacetic acid production, evaluating phosphate-solubilizing capacity, and evaluating the isolates on development assaysin green house of cabbage, peppers and tomatoes seedlings. The isolated have been identified through system vitek 2, by biochemical tests as Alcaligenes faecaliss sp faecalis, Pseudomonas putida, Proteus vulgaris, Providencia rettigueri, Serratia marcescens e Myroides sp; whereas by analysis of sequencing data for 16S ribossomal RNA the isolated bateria have been identified as A. faecalis, Myroides sp, P. putida, P. vulgaris, Providência sp e Serratia sp. In the in vitro assessment of in the screening for indolacetic acid production under presence of tryptophan all isolated bacteria produced indolacetic acid highlighting with higher concentrations by Providencia sp and Myroides sp. In the antagonism against patogenic fungi, Pythium sp, Colletotrichum sp, Colletotrichum musae, Cercosporidium sp, Curvularia sp and Sclerotium sp showed mycelial growth inhibition by volatile organic compounds produced. However, the best results were obtaind with the isolated that has been identified as Serratia sp, P. putida and Providencia sp were efficient phosphate solubilization. In trials for the development of vegetable seedlings, the means of the majority of variables for each treatment with the isolates were higher than the control. For tomato, and Serratia sp and pool, the best results showed. Por cabbage however, Providencia and Pool stood out. there was an increase in all treatments However for the chili. Pool treatment with results the best in the development promoted of seedlings of vegetables studied. The species of growth promoting rhizobacteria interactions demonstrate, that a in a plant, for another plant species may not be effective. The rhizobacteria studied here have shown the potential to be used in the development of new products for plant growth-promoting and control of phytopathogenic fungi.