Characterization of endophytic bacteria growth-promoting in potato plants (Solanum tuberosum)

Abstract

Objective/Background. The purpose of this research was to evaluate the in vitro plant growth-promoting activity of endophytic bacteria isolated in tissue from Atlantic variety potato plants from the municipality of Guasave, Sinaloa, Mexico. Materials and Methods. The bacterial population was isolated in Lb agar culture medium; two bacterial isolates were obtained from the root and two from the stem, all four Gram positive. The bacterial population of the tissue samples was expressed as (CFU/g-1). The phosphate solubilization capacity, production of chitinases and siderophores were qualitatively evaluated. Results. Partial sequencing of the 16S rDNA gene was performed, allowing the identification of associated bacterial species within the Firmicutes. 100% of the strains were identified as Bacillus sp. with identities greater than 97%: B. cereus, B. tropicus, B. thuringiensis, B. fungorum. The B. thuringiensis and B. cereus strains showed positive activity in promoting plant growth in vitro through phosphate solubilization, production of chitinases and siderophores. B. cereus and B. tropicus presented inhibitory capacity greater than 50% for Sclerothium rolfsii. Conclusion. It is relevant to continue research carried out in the laboratory, in order to determine its potential in the field, improving the production of potato crops.