Identification Of Plant Growth-Promoting Rhizobacteria Associated With Persea Americana Plantations

Abstract

Rhizobacteria have been studied for carrying out important processes in plants generating benefits, among which are activities such as biological nitrogen fixation, phosphate solubilization, production of indoleacetic acid, production of ACC deaminase and siderophores promoting plant growth. The aim of this study was to identify in vitro plant growth promoting rhizobacteria associated with avocado crops. For this purpose, rhizobacteria were isolated from soils from Salitral, Ovejas (Mountain of the María), department of Sucre, Colombia. In vitro phosphate solubilization, nitrogen fixation, siderophore production and ACC deaminase tests were carried out to finally identify them molecularly by amplification and subsequent analysis of 16S rDNA sequences. The highest population densities were 2.95 x 10⁷, 2.19 x 10⁷, 1.91 x 10⁷, 1.64 x 10⁷, 1.50 x 10⁷, 1.39 x10⁷ and 1. 30 x 10⁷ CFU/ g of soil for the farms Florida S, Sector 2, El Ojito, Sector 1R, Sector 1D, Florida N and Villa Esperanza respectively, a total of 35 morphotypes of rhizosphere bacteria were isolated, only five isolates showed the ability to promote plant growth identifying them as Burkholderia cepacia, Pseudomona aureginosa, Burkholderia cepacea, Bacillus cereus and Bacillus megaterium. These results show the importance of microorganisms as agents of biotechnological value in the search for alternatives to agricultural and environmental problems in crops of agricultural interest.