Pereira, Sofia I. A.Castro, Paula M. L.2014-10-292014-10-292013-12-06PEREIRA, Sofia I.A.; CASTRO, Paula M.L. - The effect of phosphate-solubilizing rhizobacteria on Zea mays growth on P-deficient soils. In MicroBiotec’13, Aveiro, Portugal, 6-8 December 2013 - In MICROBIOTECH 2013: Book of Abstracts. p. 211. Available at: http://microbiotec13.web.ua.pt/docs/e-book%20Microbiotec%202013%20Aveiro.pdfhttp://hdl.handle.net/10400.14/15369P-deficiency in soils is a limiting factor for plant growth. Several phosphate-solubilizing rhizobacteria (PSB) were used to enhance growth of Zea mays growing in a P-deficient soil. Strains were screened for their ability to solubilize P and to produce plant growth promoting (PGP) substances. The best-P solubilizing strains Rhodococcus sp EC35, Pseudomonas sp. EAV and Arthrobacter nicotinovorans EAPAA were inoculated in maize growing in P-deficient soils without P fertilization and amended with soluble (KH2PO4) and insoluble P (Ca3(PO4)2). Results showed that PSB significantly enhanced Z. mays biomass production in all P-treatments. Without P fertilization, bacterial inoculation increased plant dry biomass by ca. 20%, while under soluble P conditions the enhancement was higher. Pseudomonas sp. EAV was the strain that better performed improving root and shoot biomass by 104% and 60 %, respectively. In soils amended with insoluble P, plant biomass was also positive influenced by bacterial inoculation. Plant growth enhancement seems to be related not only to P-solubilization but also to other PGP traits, such as IAA and ACC-deaminase. This work shows that PSB may be used as bioinoculants and consequently constitute an attractive alternative to the phosphatic fertilizers amendments used to improve crop production.engPhosphate-solubilizing bacteriaPlant growth promotionP solubilizationconference object