Abstract

BARBOZA-GARCIA, ADRIÁN;; PEREZ-CORDERO, ALEXANDER;  and  CHAMORRO-ANAYA, LINA;. Endophytic bacteria isolated from rice culture (Oryza sativa L.) with plant growth promoting activity. Rev.Bio.Agro [online]. 2023, vol.21, n.1, pp.28-39.  Epub July 01, 2023. ISSN 1692-3561.  https://doi.org/10.18684/rbsaa.v21.n1.2023.1728.

Endophytic bacteria have become an alternative to improve crop production and replace agrochemicals which cause serious environmental damage. In this work, the plant growth promoting activity of endophytic bacteria isolated from different tissues of rice varieties of the Montería municipality, department of Córdoba, Colombia, was evaluated in vitro. The population of endophytic bacteria was isolated in R2A agar culture medium, counted and qualitatively evaluated the capacity of nitrogen fixation, phosphate solubilization and siderophore production. Endophytic bacteria with positive activities were identified by sequencing the 16S rRNA gene with 5 sets of oligonucleotides specific to the firmicutes class, beta-proteobacteria; gamma-proteobacteria; alpha-proteobacteria and actinobacteria. We isolated 107 morphotypes of endophytic bacteria with a higher presence in variety 2000 and lower in variety 67; the colonized major tissue corresponded to the root. Of the 22 isolates, 11 showed the ability to solubilize phosphate, 6 to produce siderophores, and 5 to fix nitrogen. The sequencing results proved the identity of Bacillus cereus and B. thuringiensis, which have the ability to promote growth in rice cultivation through phosphate solubilization, nitrogen fixation and siderophore production.

Keywords : Endophytic bacteria; Bacillus cereus; Bacillus thuringiensis; Colonization; Fixation of nitrogen; Production of siderophores; Plant growth promotion; Oryza sativa; Performance; Phosphate solubilization.

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