Bacillus effect on the germination and growth of tomato seedlings (Solanum lycopersicum L)

Abstract

The capacity to solubilize phosphate and to produce indole compounds Indole Acetic Acid type, was evaluated in 15 strains isolated from castor bean lignocellulosic residues (Ricinus communis). To determine the solubilizing activity of phosphates a qualitative test by using Pikovskaya culture medium was employed and for the evaluation of the production of indole compounds (IAA) a Salkowsky colorimetric analysis technique was applied. Among the microorganisms tested, the Bacillus pumilus GIBI 206 demonstrated capacity to solubilize phosphates and Bacillus subtilis GIBI 200 showed of capacity to solubilize phosphates and to produce Indoleacetic Acid (IAA). To determine the effect of the Bacillus subtilis strain on germination and growth promotion, tomato seeds (Solanum lycopersicum ‘Santa Clara’) were inoculated; the inoculation of the seeds along with the microorganism revealed statistically significant differences, during the germination stage compared to the control treatment. Nevertheless, it revealed a positive influence on the development of tomato plants, originating a significant increase on the mass and length of its stem and root. The results of this research offer the possibility of using the Bacillus subtilis as a growth promoter in tomato seedlings and in the formulation of bio-products.