Abstract

The objective of this work was to isolate, screen and evaluate in vitro, the phosphate solubilization activity of rhizobacteria isolated from Triticum aestivum rhizosphere soil in the Meknes region of Morocco. Five best isolates from 240 ones were selected based on the solubilization of insoluble phosphates (Ca₃ (PO₄)₂) in both agar plate and broth assays using National Botanical Research Institute's phosphate (NBRIP) medium. The bacterial isolates were identified based on their phenotypic and 16S rRNA genes sequencing data as Variovorax paradoxus (BT1), Pseudomonas reinekei (BT4), Pseudomonas libanensis (BT10), Pseudomonas lurida (BT11) and Pantoea agglomerans (BT12). P solubilization index of these isolates ranged from 2.88 to 3.48, amount of phosphate solubilized ranged from 24.23 to 56.95 mg P L^-1 and drop in pH of the medium ranged from 7 to 3.2. All the isolated PSB were efficient phosphate solubilizers and can be used as bioinoculants to increase the available phosphorus in the soil for wheat plant growth.

Key words: Triticum aestivum, rhizobacteria, rhizosphere, phosphate, solubilizing capacity.