The objective of this study was to isolate and select autochthonous rice rhizobacteria with the potential for the in vitro control of Pyricularia grisea, the control of fungi propagated by seeds, and the growth promotion of rice seedlings. Accordingly, 18 isolates of autochthonous rice rhizobacteria were obtained and submitted to an in vitro antibiosis test, in which mycelial growth rate and percent inhibition of mycelial growth were evaluated. In seed treatment with rhizobacteria, seeds were exposed to the bacteria, and health quality (fungi incidence), physiological quality (vigor, germination and rate of seed germination) and growth promotion of the seedlings were then evaluated. In the antibiosis test, all the isolates displayed potential for antagonism against P. grisea. There were improvements in the health quality of rice seeds. However, the isolates had no positive effect on the physiological quality of the seeds. Three isolates induced the greatest increases in shoots and roots of rice seedlings in growth promotion. Thus, we conclude that the rhizobacteria tested have the potential to control fungi in vitro, especially P. grisea, and to promote the growth of rice seedlings as well.
